ADK MODEL Air Dehydration System INSTALLATION, OPERATING & MAINTENANCE MANUAL

Transcription

1 Air Dehydration System INSTALLATION, OPERATING & MAINTENANCE MANUAL 745 Clark Avenue Bristol, Connecticut TOLL FREE: (860)

2 Thank you for choosing an ADK Air Dryer System by McIntire for your cable pressurization needs. All ADK Dryer Systems have been designed to provide years of outstanding performance and reliable service with minimal maintenance. This manual covers the installation, operation, maintenance and servicing of the Air Dryer System. Please read it carefully to better understand the dryer s operation and maintenance requirements. About Us Since 1963, McIntire Company has been engaged in the design, development, manufacturing and field-service support activities of cable pressurization air dryer systems and related accessory equipment. The needs of the telecommunications industry have changed dramatically over the last decade and we have continued to develop our product line to better serve the requirements of this dynamic market. The acquisition of several, popular industry-related product lines make "The McIntire Companies" the single largest and most complete supplier of telecommunications pressurization equipment in the world. Our extensive catalog includes: Fully Automatic Air Dryer Systems with capacities from 200 SCFD to 30,000 SCFD engineered for maximum operational and servicing flexibility, minimum maintenance and high reliability Central Office air distribution equipment including Manifolds, Racks, Cable Transducer Panels, Flow Transducer Pipe Panels, and all related fittings and tubing from the Air Dryers to the cable vault Manifolds, check valves, Air Feeder Pipe and associated fittings for use in underground air distribution Manhole and work area protection equipment including ventilator/blowers, portable heaters, manhole accessories and complete traffic warning systems, all field proven and designed to provide years of dependable service. In addition, our nationwide repair facility in Somerset, New Jersey is equipped to handle many types of repairs and maintenance including: Piston-type Compressor Rebuilding and Repair McIntire Water-seal Compressor Rebuilding and Repair Complete Dryer Rebuilding Western Progress Ventilator and Heater Repairs For more information on any of the above products or services, call our Sales & Service office toll free at

3 AUTOMATIC AIR DEHYDRATION SYSTEM INSTALLATION, OPERATING AND MAINTENANCE MANUAL DRYER SYSTEM LOG Installation Data Model No. Serial No. Compressor No. Installation Date Location Page No. Revision Date All Operating Manual Information Manual P/N Issue Date 5/01 ADDENDA Reformatted all pages. Revised Pressure Switch diagrams. Revised Part Numbers. 5/01 Yearly Maintenance Kits: Ordered Installed McINTIRE COMPANY SUBSIDIARY OF WM. STEINEN MFG. CO. 745 CLARK AVE., BRISTOL, CT

4 TABLE OF CONTENTS SECTION TITLE PAGE 1.0 GENERAL SPECIFICATIONS COMPONENT DESCRIPTIONS CHASSIS/CABINET AIR COMPRESSORS AIR INTAKE FILTERS COOLING FANS REFRIGERATION UNIT DESICCANT DRYING SYSTEM AIR COMPRESSOR CONTROL CIRCUIT ELECTRICAL SYSTEM HIGH HUMIDITY ALARM SYSTEM HIGH-LOW OUTPUT PRESSURE ALARM SYSTEM SYSTEM PRESSURE ALARM SYSTEM AIR PRESSURE AND FLOW CONTROLS PRINCIPLES OF OPERATION AIR SYSTEM AIR DRYING SYSTEM INSTALLATION PREVENTIVE MAINTENANCE TROUBLE SHOOTING PROCEDURES MAINTENANCE AND SPARE PARTS LISTS LIST OF ILLUSTRATIONS FIGURE NO. TITLE PAGE 1 SYSTEM PRESSURE ALARM SWITCH HIGH-LOW OUTPUT PRESSURE ALARM SWITCH AIR DRYER SYSTEM, FRONT VIEW AIR DRYER SYSTEM, BACKVIEW AIR DRYER SYSTEM, TOP VIEW ELECTRICAL CONTROL BOX AIR FLOW DIAGRAM WIRING DIAGRAM PREVENTIVE MAINTENANCE SCHEDULE AIR COMPRESSOR, EXPLODED VIEW

5 1.0 GENERAL 1.1 This manual contains the description, installation and maintenance instructions for the Model Air Dryer. The dryer is designed to provide a continuous dry air flow of 7000 SCFD at adjustable pressures of 0-15 PSIG for continuous feed pressure cables, pipe systems and other systems requiring dry air. The maximum emergency capacity is SCFD. 2.0 SPECIFICATIONS CAPACITY: One Compressor Operation: Two Compressor Operation: 7000 SCFD SCFD Standard Conditions of 70 F and inches mercury) POWER REQUIREMENTS: 208 or 230 VAC, 20 Amps, Single-Phase, 60 Hertz NOTE: If 230 Volts is used, BEFORE connecting power to machine, move the jumper that connects positions 2 and 3 (between wires 63 and 75) on Terminal Board A (TB-A) to positions 1 and 2 (Refer to the Wiring Diagram, Figure 8 on 18). This will bypass the 10% boost transformer used to increase 208 volt incoming power for longer compressor life and cooler operation. POWER CONSUMPTION: One Compressor Operation: Two Compressor Operation: DELIVERED AIR HUMDITY: Below 3% RH at 70 F DELIVERED AIR PRESSURE: At LOW PRESSURE Outlet : At HIGH PRESSURE Outlet: OPERATING AMBIENT TEMPERATURE RANGE: 33 F to 125 F OUTPUT PORT SIZE: LOW PRESSURE Outlet: HIGH PRESSURE Outlet: ALARMS: High/Low Output Pressure High Humidity System Pressure GAUGES: Output Flow ( SCFD) System Pressure (0-60 PSIG) Output Pressure (0-15 PSIG) 11.1 Amps 16.5 Amps Adjustable 0-15 PSIG 25 PSIG Maximum ½ FNPT ½ FNPT DIMENSIONS: 49" High x 30 1/2" Wide x 24 1/4" Deep WEIGHT: 450 Pounds 3.0 COMPONENT DESCRIPTIONS Refer to Figures 3,4,5,6 3.1 CHASSIS/CABINET. The cabinet has a hinged top door and removable front door. The electrical box is mounted to the top door and the box cover is secured by four (4) 1/4 turn fasteners. The front door is secured by two (2) 1/4 turn fasteners The air compressors are mounted in the acoustically insulated and ventilated lower section of the unit. 3.2 AIR COMPRESSORS. The air compressors are mounted on slide out bases and can be easily removed form the housing by first removing two (2) hold down bolts from the front corners of the sliding base. To remove the compressor, CAREFULLY slide the compressor out from the housing and disconnect the discharge tubing and the quick connect electrical terminals Each air compressor is direct-driven by a 3/4 HP motor which has a built in thermal overload protector which will automatically reset once the motor cools to normal temperatures Each air compressor is a single-stage, twocylinder piston compressor which utilizes Teflon rings and skirts. No lubrication is required for either the compressor or the motor. It is recommended that the rings and valves be replaced annually. 3.3 AIR INTAKE FILTERS. Each air compressor is equipped with two (2) intake filters. The filters have replaceable elements and it is recommended that the elements be replaced every three (3) months. Replacement elements for the first year of operation are furnished with the air dryer. 3.4 COOLING FANS. The lower section of the unit is ventilated by two (2) fans that operate continuously only when the front door is installed. The fans are mounted directly over the air compressors. 3.5 REFRIGERATION UNIT. The compressed air from the air compressors is partially dried in the refrigeration unit before it is delivered to the desiccant drying system. The replaceable refrigeration unit consists basically 1

6 of a refrigeration compressor, condenser, condenser fan and a heat exchanger. The unit can easily be removed and replaced if trouble develops TEMPERATURE GAUGE. Mounted on the front panel, the temperature gauge measures the temperature in the refrigeration unit heat exchanger. The temperature will be maintained within the range of 35 F and 50 F SYSTEM PRESSURE ALARM SWITCH. If the air dryer system pressure falls below 15 PSIG due to increased output flow (above 7000 SCFD) or if the air compressors require maintenance, the system pressure alarm switch (mounted on the system pressure gauge) will close and both air compressors will run continuously. Simultaneously the system pressure alarm lamp will light and office alarm contacts will close. If necessary the pressure switch can be adjusted as follows: 3.6 DESICCANT DRYING SYSTEM. The desiccant drying system completes the drying process started in the refrigeration unit. The system consists basically of two (2) desiccant filled towers with tower heaters submerged in the desiccant, two (2) three-way solenoid valves and a timer assembly DESICCANT TOWERS. The desiccant towers are used to final dry the air from the refrigeration unit to a dew point below 40 F. Each tower dries the air for a period of five (5) hours. There are outlet filters in each tower to prevent the desiccant material from passing out of the towers TOWER SOLENOID VALVES. The three-way tower solenoid valves route the air through the desiccant towers and direct the wet air purge to the water drain outlet. The valves are controlled by a timer and are operated once each five (5) hours TOWER TIMER ASSEMBLY. The tower timer assembly controls the operation of the tower solenoid valves and the tower heaters. A complete timer cycle is ten (10) hours TOWER OUTLET FILTERS. These porous bronze filters prevent desiccant from passing out of the towers. They should be changed annually. The filters are easily replaced by first disconnecting the flexible tubing from the top of each tower and then unscrewing the filter from the tower. 3.7 AIR COMPRESSOR CONTROL CIRCUIT. The air compressor control circuit maintains proper compressor operation by automatically cycling the compressors and selecting one (1) or two (2) compressor operation based on output demand COMPRESSOR TIMER ASSEMBLY. During normal operation (when the air dryer output is 7000 SCFD or less) each compressor runs for 7-1/2 minutes and is off for 7-1/2 minutes. The compressor cycling is controlled by the compressor timer assembly. FIGURE 1. System Pressure Alarm Switch A. Shut off the output air flow from the air dryer. Depress the reset switch to make sure that only one air compressor is operating. B. Pull up on the adjustment knob on the by-pass relief valve (valve mounted on the top of the refrigeration heat exchanger). Note the pressure indicated on the system pressure gauge. C. Slowly turn the adjusting knob on the valve counterclockwise to lower the system pressure to 15 PSIG. D. Loosen the locking ring on the pressure switch (turn it counter-clockwise) and then rotate the inner barrel of the switch clockwise (in) to lower the pressure setting, or counterclockwise (out) to raise the setting. The setting should be made so that the alarm is just activated at 15 PSIG. Once the proper setting is reached, carefully tighten the locking ring on the pressure switch. Note: The switch is very sensitive and the setting may be affected after tightening the locking ring. Check the setting by adjusting the by-pass relief valve to approximately 20 PSIG (as shown on the system pressure gauge) and then readjusting the relief valve back to 15 PSIG to confirm that the setting is correct. It may take several attempts before the proper setting is achieved. It may be necessary to depress the reset switch during the adjusting procedure to return to one compressor operation. E. After the adjustment has been completed, turn the adjusting knob on the by-pass relief valve clockwise to increase the system pressure to the original level. Then 2

7 lock the valve by pushing the knob in towards the valve body RESET SWITCH. The reset switch will return the air dryer to one compressor operation after the system pressure alarm switch has operated. The unit will continue to operate with the compressors alternating provided that the system pressure remains above 15 PSIG RESET OVERRIDE SWITCH. A striker plate mounted on the cam of the compressor timer assembly and a micro switch provide the air dryer with an automatic reset feature. In the event that the air dryer switches to the emergency capacity mode (two compressor operation) because of a power failure or short term increase in output air requirements, the timer switch will attempt to reset the air dryer to the normal capacity mode (one compressor operation) every 15 minutes. If the air requirements are in the range of SCFD, the reset to normal capacity will be permanent. If the air requirements are above 7000 SCFD, the air dryer will immediately return to the emergency capacity mode. If it is known that the air output requirements will be above 7000 SCFD for an extended period of time then it is recommended that the reset override switch be moved to the "on" position. In the "on" position it will override the automatic reset feature and keep the air dryer in the emergency capacity mode continuously. It will also open the system pressure alarm circuit so that there will be no alarm sent to the remote alarm monitoring system. The red "System Pressure Alarm" lamp will always be on when the unit is in two compressor operation COMPRESSOR POWER CONTACTORS. The power contactors, which are operated by the compressor timer or the system pressure alarm relays, control the operation of the air compressors. The contactors are equipped with heavy duty, 30 amp contacts. 3.8 ELECTRICAL SYSTEM. The Wiring Diagram is shown in Figure 8 (page 18). The air dryer is designed to operate from a 208 or 230 volt, single phase, 60 Hertz power source and should be fused for 20 amperes. NOTE: If 230 Volts is used, BEFORE connecting power to machine, move the jumper that connects positions 2 and 3 (between wires 63 and 75) on Terminal Board A (TB-A) to positions 1 and 2 (Refer to the Wiring Diagram, Figure 8 on 18). This will bypass the 10% boost transformer used to increase 208 volt incoming power for longer compressor life and cooler operation. The wiring in this air dryer is color-coded for easier voltage identification. Red wires are used for the 230 volt circuit. Black wires are for the 115 volt wiring, and orange/white wires have no voltage (dry) and are alarm circuit wires START-STOP SWITCH AND SWITCH HEATER. The start-stop switch is located on the left side of the front panel. The switch is equipped with a 18.6 ampere switch heater. If an overload in the air dryer occurs, the mechanism in the switch moves the switch lever to the mid-position. The switch may be reset by waiting two minutes and then moving the switch lever to the "off" and then to the "on" position POWER LAMP. This white lamp, which is located on the left side of the front panel, is energized when the start-stop switch is moved to the "on" position BOOST TRANSFORMER. All electrical components in the air dryer are rated for either 230 volts or 115 volts, therefore, a 10% boost transformer is included in the circuit and is utilized when the incoming power source is 208 volts. The air dryer is factory wired for 208 volts. NOTE: If 230 Volts is used, BEFORE connecting power to machine, move the jumper that connects positions 2 and 3 (between wires 63 and 75) on Terminal Board A (TB-A) to positions 1 and 2 (Refer to the Wiring Diagram, Figure 8 on 18). This will bypass the 10% boost transformer used to increase 208 volt incoming power for longer compressor life and cooler operation CONTROL TRANSFORMER. The control transformer reduces the incoming power to 115 volts to operate the various air dryer control and alarm components which are rated for 115 volts. 3.9 HIGH HUMIDITY ALARM SYSTEM. The humidity alarm is designed to open a circuit and shut off air flow to the high and low pressure outlets in the event that the humidity of the delivered air rises above the humidity alarm point. The main components of this system are the Humidity Monitor Board, Humidity Alarm Relay, Humidity Solenoid Valve, Humidity Alarm Lamp, Sensing Element and the Sensing Element Cord. The humidity alarm circuit is shown in the wiring diagram (Figure 8) and the operation of the alarm system is as follows: a. The humidity solenoid valve is connected to the humidity alarm through the normally open contacts of the 3

8 humidity relay. The office alarm circuit is connected to the normally closed contacts of the humidity alarm relay. The office alarm circuit terminates at an alarm plug located at the rear of the unit. b. During normal operation, the humidity monitor board will be closed, energizing the humidity relay and the solenoid valve. The humidity alarm lamp is out, the office alarm circuit is open and the solenoid valve permits dry air to pass into the cable system. c. If the humidity of the air rises above the alarm point, the humidity monitor board contacts open de-energizing both the humidity relay and the solenoid valve. The humidity alarm lamp is energized, the office alarm circuit closes, and the solenoid valve shuts off airflow to the high and low pressure outlets HIGH-LOW OUTPUT PRESSURE ALARM SYSTEM. High-Low Pressure Alarm Switch Pressure Alarm Relay Pressure Alarm Lamp The high-low pressure alarm switch is connected electrically to the pressure alarm relay coil and the pressure alarm lamp. It will provide a visual alarm and a closed office alarm circuit if the air dryer output pressure falls below or rises above preset values. The alarm is factory preset to operate at 6.5 ± 1.5 and 10 ± 1.5 PSIG. If necessary the switch can be adjusted as follows: alarm setting. After finding the proper setpoint, tighten the locking ring on the switch. Note: The switch is very sensitive and the setting may be affected after tightening the locking ring. Check the setting by adjusting the output pressure back to the normal level and then readjusting the output pressure back to desired alarm level to confirm that the setting is correct. It may take several attempts at adjusting the switch before the proper setting is achieved. b. The low pressure alarm setting is made by adjusting the pressure to the pressure at which the low alarm should operate. The locking ring on the corresponding switch labeled High Pressure should then be loosened (turned counterclockwise) and the inner barrel if the switch rotated turned out (counter-clockwise) to raise and in (clockwise) to lower the low alarm setting. After finding the proper setpoint, tighten the locking ring on the switch SYSTEM PRESSURE ALARM SYSTEM System Pressure Alarm Relays (2) System Pressure Alarm Lamp The relays which are operated by the system pressure alarm switch (described in section 3.7.2) control the air compressor power contactors and provide a visual (system pressure alarm lamp) and office alarm contact closure in the event that the air dryer switches to maximum emergency capacity. The office alarm circuit terminates at an alarm plug located at the rear of the unit AIR PRESSURE AND FLOW CONTROLS BY-PASS RELIEF VALVES AND MUFFLERS. The air dryer is equipped with two (2) by-pass relief valves. One valve is located at the top of the refrigeration heat exchanger and the other is located at the bottom of the humidity sensing tube. These valves are used to limit the system pressure to a maximum of 25 PSIG. Mufflers are installed in the valve outlets to reduce noise level. If it becomes necessary to adjust the valves, first shut off the output air flow to the cable system. Then proceed as follows: Figure 2. High-Low Pressure Alarm Switch a. The high pressure alarm setting is made by adjusting the pressure regulator to give the pressure at which the high alarm should operate. The locking ring on the corresponding switch labeled High Pressure should then be loosened (turned counterclockwise) and the inner barrel if the switch rotated turned out (counterclockwise) to raise and in (clockwise) to lower the high a. Pull up on the adjusting knob on both valves. b. Turn the adjusting knobs all the way out (counterclockwise). The system pressure will drop below 10 PSIG and both air compressors will be operating. c. Turn the adjusting knob on the heat exchanger bypass valve to raise the system pressure (as noted on the system pressure gauge) 2 PSIG. Then turn the adjusting knob on the humidity sensing tube by-pass valve to raise 4

9 the pressure another 2 PSIG. Alternately adjust the valves in 2 PSIG steps until the system pressure is PSIG. NOTE: If the automatic reset system cycles the air compressors while the by-pass valve adjustments are being made, wait approximately 30 seconds and start the adjusting procedure again at step b. d. Push the adjusting knobs back in to lock the valve settings. e. Depress the reset switch to return the air dryer to the normal one compressor operation. It will be noted that the system pressure gauge will drop 1-2 PSIG with one compressor operation SYSTEM PRESSURE GAUGE. This 0-60 PSIG gauge measures the air dryer system pressure AIR FLOWMETER. The air flowmeter measures the total instantaneous flow of air to the cable system. The flowmeter range is SCFD HIGH PRESSURE SHUT-OFF VALVE. This is a 1/4-turn ball valve which is used to shut off the high pressure outlet if it is not being used. The valve is open when the handle is horizontal OUTPUT PRESSURE REGULATOR. This is a single-stage regulator that reduces the system pressure to the desired cable system pressure. The regulator is equipped with a self-contained relief valve feature for ease of making lower output pressure settings. The regulator can be adjusted to the required output pressure by loosening the lock nut and turning the handle clockwise to increase, or counterclockwise to decrease the pressure. When the desired setting has been made the locknut should be retightened OUTLET PRESSURE GAUGE. This 0-15 PSIG gauge measures the pressure at the low pressure outlet. 4.0 PRINCIPLES OF OPERATION 4.1 AIR SYSTEM The air flow schematic is shown in Figure 7 on page During operation, ambient air is drawn in through air filters and into the air compressors where it is compressed to a maximum pressure of 25 PSIG. The compressed air flows through precoolers to the refrigerated heat exchanger The two air compressors are controlled by a 15-minute timer or by the system pressure alarm switch. During normal operation, when the air dryer output is 7000 SCFD or less, each air compressor alternately runs for 7-1/2 minutes and is off for 7-1/2 minutes. If the system pressure falls below 15 PSIG due to increased output flow or if the compressors require maintenance, the system pressure alarm switch will close. The timer override relays will lock in and switch the system to maximum emergency capacity. At the same time the "System Pressure Alarm" lamp will light and alarm contacts will close. Both air compressors will run continuously until the reset switch on the electrical box is depressed. NOTE: Since the compressors operate at low pressure, the unit can be operated indefinitely in the emergency capacity mode without significant deterioration of compressor performance or life The air dryer is equipped with an automatic reset feature so that it is not necessary to manually reset the unit in the event that the air dryer switches to the emergency capacity mode because of a power failure or a short term increase in output air requirements The compressed air is cooled in the heat exchanger to between 35 F and 50 F to remove most of the moisture. The condensed moisture is purged from the heat exchanger through a capillary tube which ejects the moisture through the water drain outlet in the rear of the unit. By-pass relief valves installed in the heat exchanger outlet and at the bottom of the humidity sensing tube are adjusted to the limit the system pressure to 25 PSIG The cooled, partially dried air flows from the heat exchanger to a solenoid valve and into one of the desiccant towers for final drying From the desiccant tower most of the dry air is routed to the humidity sensing tube. A small amount of dry air from the tower being utilized is routed through the tower being reactivated to purge its moisture. The moisture laden air flows through a purge capillary tube to the water drain outlet The dry air flows from the humidity sensing tube through the high humidity solenoid valve to the air flowmeter. The air flow then splits. One tube carries air to the low pressure output regulator, a high/low pressure alarm switch assembly, and the low pressure outlet. The other tube connects to the high pressure shut-off valve and on to the high pressure outlet. 5

10 4.2 AIR DRYING SYSTEM The air drying system consists of a replaceable refrigeration unit, two desiccant filled towers equipped with tower heaters surrounded by in the desiccant and filters in both the inlet and outlet, two three-way solenoid valves and a timer assembly Compressed air from the air compressor(s) is delivered to the refrigeration heat exchanger at a maximum pressure of 25 PSIG where it is cooled to between 35 F and 50 F and partially dried. The condensed moisture is purged from the heat exchanger through a capillary tube to the water drain outlet at the rear of the unit The desiccant drying system is arranged and cycled so that as one tower delivers dry air to the cable system, the desiccant in the other tower is being reactivated or dried. The tower functions are controlled by the inner timer assembly and the sequence of operation is as follows: a. Tower No. 1 Partially dried air from the refrigeration unit passes through solenoid valve no. 1 and enters the tower through a filter where it is dried to below -40 F dew point as it passes over the desiccant. The dry air leaves the tower through a filter and is routed to the humidity sensing tube and finally to the dry air outlets. The air is dried in the tower for a five (5) hour period. b. Tower No. 2 Simultaneously with the operation of tower no. 1, solenoid valve no. 2 is open to the tower purge capillary and the heater in tower no. 2 is energized. The desiccant is heated for a period of 2-1/2 hours. After the heating period, the tower heater is de-energized and the tower is allowed to cool for a period of 2-1/2 hours. During this entire 5 hour period, a small amount of dry air from tower no. 1 is purged through tower no. 2 and solenoid valve no. 2 to the tower purge capillary and then out the water drain outlet. c. At the end of the 5 hour period, the timer will reverse the functions of the towers. The reactivated tower no. 2 will dry the air, and tower no. 1 will be reactivated. 5.0 INSTALLATION 5.1 Inspect the air dryer for evidence of exterior or interior shipping damage and immediately report any such damage to the carrier. 5.2 Remove the wooden shipping blocks from the air compressor mounting bases To remove the air compressor shipping blocks first remove the front door from the air dryer. Remove the two hold-down bolts from the front corners of the sliding bases. CAREFULLY slide the compressors part way out from the housing. Remove the nuts, bolts and wooden shipping blocks from each side of the air compressor mounting bases. Slide the compressors back into the housing and install the hold-down bolts. 5.3 Locate the air dryer so as to provide adequate air circulation through the unit. 5.4 The air dryer is supplied with a water drain elbow that should be installed in the water drain outlet at the rear of the unit. This drain can be piped to a floor drain or discharged into a bucket. 5.5 The air dryer is factory wired for 208 volt operation. If the unit is to be operated from a 230 volt power source it will be necessary to make one minor wiring change which is outlined in section A six-foot long, three-conductor power cord with a twist-lock plug is furnished with the unit and should be plugged into the 208 or 230 volt power supply outlet. The circuit should be fused for 20 amperes. 5.7 The High/Low Outlet Pressure Alarm, Humidity Alarm, and System Pressure Alarm contacts are connected to Terminal Block "D" which is mounted to the inside of the rear panel directly above the Boost Transformer. The three alarms are connected in parallel so that any alarm contact closure will provide a contact closure across terminals 1 and 6. Route the Office Alarm pair through the Alarm Grommet in the rear panel and up to Terminal Block "D". Connect one lead to terminal 1 and the other lead to terminal 6. The air dryer alarm system is wired at the factory to provide a closed-on-alarm (normally open), common signal (single office alarm pair). The alarm system can be modified in the field to provide these other types of signals: Closed-on-Alarm with separate signals for each alarm condition Open-on-Alarm common signal Open-on-Alarm with separate signals for each alarm condition Please contact the McIntire/ADK service department at and ask for TSB ADK for complete wiring instructions. 6

11 Although it is recommended that the Office Alarm pair be connected directly to Terminal Block "D", a Twist Lock Alarm Plug set is provided with the Air Dryer Accessory Kit which can be installed on the rear panel. To install, remove the grommet from the upper alarm hole and mount the male plug in its place using the screws and nuts provided. Route wire 83 and wire 84 from the plug up to Terminal Block "D" and connect them to terminals 1 and 6 respectively. Connect the Office Alarm pair to the female receptacle. 5.8 Move the start-stop switch to the "on" position. As soon as the system pressure rises above 15 PSIG depress the reset switch (located on the top of the electrical box) to switch the air dryer to normal capacity mode. 5.9 Check that the system pressure gauge is reading 25 PSIG with no air flow from the unit. If necessary, adjust the by-pass relief valves as outlined in section Check that the heat exchanger temperature is within the range of 35 F to 50 F When the humidity alarm lamp goes out the air dryer may be connected to the cable system If necessary readjust the high-low pressure alarm to the desired settings. The adjusting procedure is outlined in section Adjust the air outlet pressure regulator to obtain the desired outlet pressure as indicated on the outlet pressure gauge Check all air fittings for leakage It is recommended that the air dryer be rechecked after 24 hours of operation. 6.0 PREVENTIVE MAINTENANCE To ensure continued satisfactory operation, it is recommended that inspection and maintenance procedures be performed at scheduled intervals. Refer to Figure 9 on page 19 for a complete maintenance schedule chart. 6.1 A maintenance kit supplied with each air dryer provides all the parts necessary for normal maintenance during the first year of operation (12 filter felts for air compressor air intake filters quarterly replacement). After the first year an annual maintenance kit, P/N 15000M, should be ordered. It contains the following parts: QTY. P/N DESCRIPTION Compressor Maintenance Kit* Tower Outlet Filter Capillary Drain Kit * Each compressor maintenance kit contains new piston rings and valves and inlet filter felts. 6.2 QUARTERLY MAINTENANCE AND INSPECTION Replace the filter felts in the air compressor intake filters. Do not attempt to clean and reuse the old felts Check the operation of the humidity alarm system. Refer to sections 3.9 and Check the operation of the high and low output pressure alarms. Refer to section Check that the heat exchanger temperature is within the range of 35 F to 50 F. 6.3 ANNUAL MAINTENANCE AND INSPECTION Change the piston rings and valves in the air compressors as follows: (refer to Figure 10 on page 20) a. Disassembly 1) Remove the air compressors from the housing. It will not be necessary to remove the compressors from the mounting bases. 2) Disconnect the manifold tubing at the elbow fittings on both heads. 3) Remove the four (4) cylinder head screws and lift off the cylinder head and valve components. 4) Remove the two (2) cylinder screws and two (2) lockwashers and lift out the cylinder. 5) Remove the piston seals, piston rings and rider rings. 6) Clean all components with a non-flammable non-toxic, chlorine free cleaning solvent. b. Assembly 1) Install the new piston seals, piston rings and rider rings on the piston. Locate the ring joints approximately opposite each other. 7

12 2) Slide the cylinder over the piston and attach the cylinder to the bracket with the screws and lockwashers. Tighten the screws finger tight. Move the piston to the top dead center position and adjust the cylinder flush with the top of the piston. Tighten the cylinder screws. 3) The valve assemblies furnished in the maintenance kit are tied together with a plastic tie. They are assembled in the proper sequence. Do not cut the tie until the valves are partially installed. If the tie has already been cut or is not present, refer to figure 10 on page 20 to determine the proper sequence and alignment of the valves, valve plate and gaskets. 4) Place the valve assembly on the head with the alignment hole in the valve assembly in line with the alignment hole in the head. Insert screws through two of the holes in the head. Place the head and valve assembly on the cylinder and position them with the manifold elbow facing in toward the compressor. Loosely engage the two screws in the cylinder. Cut the plastic tie and install the two remaining screws and lockwashers. Do not tighten the screws at this time. NOTE: On top of each cylinder head the end of two cooling fins have been omitted. These are always in the discharge ports. 5) Install manifold nuts and new seals on the manifold and assemble it to the elbow fitting on the head assembly. Do not tighten the nuts. 6) Install the second head assembly and assemble the manifold. Tighten all head screws and the manifold nuts. 7) Install the air compressor in the air dryer. Start the air dryer and soap test all of the compressor fittings. Note: A test gauge is available to confirm proper compressor output prior to installation in the dryer (testing can also be performed with the compressor installed in the dryer). Order Part Number Check the operation of the system pressure alarm as follows: a. Complete the procedures outlined in steps a, b, and c in section b. When the system pressure reaches approximately 15 PSIG both air compressors should start operating and the system pressure alarm lamp should light. In addition the office alarm contacts should close. If the system is operating properly complete step e of section c. If necessary adjust the system pressure alarm switch as outlined in step d of section then complete step e Replace the outlet filters in the top of the desiccant towers. Refer to section Replace the drain strainer in the refrigeration system and the capillary drain tubing that runs from the drain strainer to the rear of the dryer. 7.0 TROUBLE SHOOTING PROCEDURES Outlined below are the recommended steps that should be taken to determine the proper corrective action in the event of a failure in the ADK Model Air Dryer. The troubleshooting procedures cover four categories of failure mode: 7.1. Air Dryer is not running 7.2. Air Dryer is in Humidity Alarm 7.3. Air Dryer is in Outlet Pressure Alarm 7.4. Air Dryer is in System Pressure Alarm While these procedures do not cover all possible causes of failure, they do cover the most likely causes of failure for this type of electro-mechanical equipment. If the cause of a failure cannot be determined after following these procedures, call McIntire/ADK at and ask for "service assistance". NOTE: Recommended Test Equipment: Multimeter ( volt-ohmmeter) Clamp-on Ammeter (amprobe or equivalent) Thermometer (dial type with a metal stem) 7.1 Air Dryer is not running (Power lamp is out, no power to any electrical component in the unit) Make sure that the Air Dryer start/stop switch is in the "on" position Check the incoming power circuit at terminal block "A" If the air dryer is wired for 208 volt incoming power, check for voltage across terminals 4 and 5 using an AC voltmeter If the air dryer is wired for 230 volt incoming power, check for voltage across terminals 1 and 5. If no voltage is read, check the incoming power circuit breaker and for an open in the external wiring circuit. 8

13 7.1.3 Check the air dryer internal main power circuit at the start/stop switch A If the unit is wired for 208 volt incoming power, check for 230 volts across the top terminals of the start/stop switch. If no voltage is read, check for 230 volts across wires 68 and 75 at the boost transformer (mounted to the inside of the upper rear panel). If no voltage is read, check for 208 volts across wires 64 and 67 at the boost transformer. If voltage is read, replace the boost transformer (P/N 3739). If no voltage is read repair the wiring between terminal block "A" and the boost transformer B If the unit is wired for 230 volt incoming power, check for 230 volts across the top terminals of the start/stop switch. If no voltage is read, repair the wiring between terminal block "A" and the start/stop switch If 230 volts is read across the top terminals of the start/stop switch, move the switch to the "on" position, and check for voltage across the bottom terminals of the switch. If no voltage is read: a) Replace the plug-in heater in the front of the switch b) Or, replace the start/stop switch Air Dryer is in Humidity Alarm Determine whether the Humidity Alarm is caused by high humidity in the outlet air or by a faulty component in the humidity alarm circuit by unplugging the sensing element cord from the top of the humidity sensing tube If, with the sensing cord unplugged the humidity alarm lamp goes out, the alarm contacts open, and the humidity shut off solenoid valve opens, the alarm is caused by high humidity Check that the refrigeration temperature gauge is reading between 35 F and 50 F. Also, verify that the temperature gauge is accurate by removing the temperature gauge bulb from the well at the front of the refrigeration unit, and inserting a test thermometer. If the refrigeration temperature is above 50 F, perform the following checks: a) Remove the electrical cover from the front of the refrigeration compressor. Check that there is 230 volts across wires 23 and 24. If no voltage is read, repair the wiring between the refrigeration compressor and terminal block "B" in the electrical box. If 230 volts is read, replace the cover. b) Check that the condenser fan is operating. If it is not, check for an obstruction between the fan blade and the fan orifice, or, replace the fan motor. c) Check that the refrigeration condenser fins are free of debris. Clean the fins using a brush or with compressed air. d) Check that the refrigeration compressor is running and that the system is fully charged using a clampon ammeter. A fully charged system will draw between 2.8 and 3.5 amps (compressor and fan motor). Low current (below 2.8 amps) indicates either a low refrigeration charge in the system or a defective compressor. If the current draw is above or below the normal range, replace the refrigeration unit Check that the refrigeration heat exchanger is draining properly. Turn the air dryer off and allow the system pressure to fall to 0 PSIG. Disconnect the drain capillary tubing from the elbow fitting at the bottom of the heat exchanger. a) If a stream of water flows from the elbow fitting, the drain capillary tubing is restricted and must be replaced. b) If no water flows from the elbow fitting, check that the heat exchanger drain strainer is not restricted by turning the air dryer on and making sure that a steady flow of air (and some water) escapes from the elbow fitting. Or, visually inspect the strainer by removing it from the heat exchanger using an 11/16 inch open end wrench. Clean the strainer by removing the elbow and bushing from it and then rinsing it with water. Reassemble the fittings, install the strainer into the heat exchanger, and connect the capillary tubing. c) Disconnect the 1/4" plastic tubing from the drain junction fitting assembly (located at the rear of the middle shelf) and verify that there are no restrictions in the fittings or the short piece of 1/8" copper capillary tube. Replace the 1/4'" tubing and check the end of the external drain tubing to make sure that it is not restricted If the refrigeration unit is operating and draining properly, perform the following tests of the desiccant drying system: a) Note the position of the "percent dial" on the desiccant tower timer assembly (located in the electrical box) relative to the black pointer on the timer frame. Allow the air dryer to run for 18 minutes. The "percent dial" should move 3%. If it does not move, make sure that the dial is not contacting the frame. If it is, loosen the set screw and move the dial away from the frame (be careful not to change the set point). Perform this test again. If 9

14 the dial still does not move, replace the desiccant tower timer assembly. b) Again, note the position of the "percent wheel" (the timer must be returned to the same position once these tests are completed). Disconnect the drain capillary tubing from both of the desiccant tower solenoid valves. Place a clamp-on ammeter around one of the heater leads on desiccant tower #2 (closest to the rear of the unit). Manually rotate the "percent dial" on the tower timer assembly counterclockwise until you reach 0%. At 0% (±1%), solenoid valve #2 should begin releasing air to atmosphere. If it does not, check for 230 volts across wire 29 on the desiccant tower timer assembly and wire 20 on terminal 6 of terminal block "B". If voltage is read, replace the timer assembly. If no voltage is read, replace the solenoid valve. Slowly rotate the dial to 2% (+2/-0%). At this point, the heater in tower #2 should energize (approximately 2.5 amps should be read). If it does not, check for 230 volts across wire 31 in the tower timer assembly and wire 22 on terminal 5 of terminal block "B". If no voltage is read, replace the timer assembly (P/N 11587). If voltage is read, check for 230 volts across wires 31 and 22 where they connect to the desiccant tower. If no voltage is read, repair the wiring between the tower and the timer assembly, if voltage is read, repair the electrical connections at the heater, or replace the desiccant tower. Continue rotating the dial until 27% (±2%) is reached. At this point, the heater in tower #2 should de-energize. If it does not, replace the timer assembly. Rotate the dial to 50% (±1%). Solenoid valve #2 should stop releasing air to atmosphere and solenoid valve #1 should begin releasing air. If solenoid valve #2 continues to release air to atmosphere, check for 230 volts across wire 29 on the tower timer assembly and wire 20 on terminal 6 of terminal block "B". If no voltage is read, replace the solenoid valve. If voltage is read, replace the timer assembly. Rotate the dial counterclockwise to 0% and make sure that the heater in tower #2 does not energize. If it does, replace the timer assembly. c) Repeat step "b" for desiccant tower #1 beginning at 50% on the "percent dial". The heater should energize at 52% (+2/-0%) and de-energize at 77% (±2%). Substitute wire 27 for wire 29, and wire 33 for wire 31. NOTE: Solenoid valve #1 should continuously release air to atmosphere ONLY when the timer dial is between 50% and 0%. Heater #1 should be continuously energized ONLY when the timer dial is between 52% and 77%. Solenoid valve #2 should continuously release air to atmosphere ONLY when the timer dial is between 0% and 50%. Heater # 2 should be continuously energized ONLY when the dial is between 2% and 27%. d) Connect the capillary tubing to the solenoid valves. Disconnect them from the drain junction assembly at the rear of the unit and make sure that they are not restricted. Rotate the timer dial counterclockwise and check for continuous air flow from the tubing connected to solenoid valve #2 when the dial is between 0% and 50% and from the tubing connected to solenoid valve #1 when the dial is between 50% and 0%. e) Return the "percent wheel" to its original position The three major components of the Humidity Alarm system are the humidity monitor board, the humidity alarm relay, and the humidity shut off solenoid valve. If, with the sensing element cord unplugged any of the alarm conditions remain, there is a defective component in the humidity alarm circuit. Leave the sensing element cord unplugged while performing the following checks Humidity Monitor Board a) Check for 115 volts across the HOT and NEUT. terminals on the humidity monitor board. If no voltage is read, repair the wiring between the board and terminal board "C". b) Check for 115 volts across the NEUT. terminal and terminal 2 on the humidity monitor board. If no voltage is read, repair the wire jumper that connects terminal 2 to the HOT terminal. c) Check for 115 volts across the NEUT. terminal and terminal 3 on the humidity monitor board. If no voltage is read, replace the humidity monitor board. d) Check for 115 volts across the NEUT. terminal and terminal 1 on the humidity monitor board. If voltage is read, replace the humidity monitor board Humidity alarm relay a) Check for 115 volts across the C1 and C2 terminals on the relay. If no voltage is read, repair the wiring between the relay and the humidity monitor board. b) Check for 115 volts across the NEUT. terminal on the humidity monitor board and terminal 1 on the relay. If no voltage is read, repair the wiring between the relay and the humidity monitor board. c) Check for 115 volts across terminal 1 and terminal 3 on the relay. If voltage is read, replace the relay. 10

15 d) Using an Ohmmeter, check for contact closure across terminals 7 and 8 on the relay. If there is a closure, replace the relay Humidity shut off solenoid valve The humidity shut off solenoid valve is open when it is energized. If the humidity monitor board and the humidity alarm relay are functioning properly and no air is passing through the solenoid valve, check for 115 volts across wires 37 and 38 where they connect to the solenoid valve coil. a) If no voltage is read, check for an open in wire 37 or wire 38. b) If 115 volts is read, replace the solenoid valve Air Dryer is in Outlet Pressure Alarm The high/low pressure switch monitors the air pressure at the low pressure outlet. If the air dryer is in an Outlet Pressure alarm, and no other alarm condition exists, continue with this section. If any other alarm condition exists, repair the cause of that alarm and the Outlet Pressure alarm will most likely clear Check the Outlet Pressure Gauge reading If the outlet pressure is normal, reset the High/Low pressure switch by following the procedure outlined in section If you are not able to reset the alarm points, replace the switch If the outlet pressure is above or below normal, adjust the Outlet Pressure Regulator to attain the normal pressure Air Dryer is in System Pressure Alarm When the Air Dryer system pressure drops to 15 PSIG the System Pressure alarm circuit is activated. Increased air demand, failure of one of the air compressors to start, and low output capacity of an air compressor are the most likely causes of a system pressure alarm Increased air demand If the increased air demand is due to a temporary air leak in the field, move the override switch to the "on" position. This will permit both of the air compressors to operate continuously without the automatic reset switch trying to shut one of them off every fifteen minutes. It will also clear the alarm contact closure at the alarm terminal block. The system pressure alarm lamp will remain illuminated until the system pressure rises above 15 PSIG and the override switch is moved to the "off " position If the increased air demand is expected to last several weeks, and with one compressor operating, the system pressure has stabilized at or above 12 PSIG, the system pressure switch can be reset to permit one compressor operation without the system pressure alarm activating. Set the switch so that alarm is activated at 10 PSIG by following the steps outlined in section One of the air compressors fails to start Power to the air compressors is supplied through the power contactors, which are controlled by the Air Compressor Timer assembly. The compressor timer assembly supplies power to the coils of the power contactors alternately every 7.5 minutes. If one of the air compressors fails to start when the other one shuts down, perform the following tests Test the air compressor motor by checking for 230 volts AC across the power leads where they connect to the motor. (Wires 11 and 12 for compressor 2 or wires 13 and 14 for compressor 1.) a) If 230 volts is read, there is an internal starting circuit problem with the motor and the air compressor assembly must be replaced. If the air compressor assembly is known to be more than 10 years old, it is probably not worth repairing the motor. Otherwise, contact the McIntire/ADK Service Department at to arrange for repair of the motor. b) If no voltage is read, test the power contactor associated with that air compressor Check for 230 volts AC across the T1 and T2 terminals on the power contactor. a) If 230 volts is read, repair the wiring between the power contactor and the air compressor. b) If no voltage is read, check for 230 volts AC across the L1 and L2 terminals on the contactor. If no voltage is read here, repair the wiring between the contactors and terminal block "B". c) If there is 230 volts across L1 and L2, check for 115 volts AC across the two coil terminals of the contactor. (These terminals are not labeled, they are located on the sides of the contactor.) If there is 115 volts across the coil terminals, replace the power contactor. If there is no voltage at the coil, test the air compressor timer assembly Check for 115 volts AC across the "common" terminal of micro switch #4, on the timer assembly, and terminal 1 on terminal block "C". 11

16 a) If no voltage is read, repair the wiring between the micro switch and the terminal block. b) If 115 volts is read, check for 115 volts across either the N.C. terminal (if compressor 2 fails to start), or, the N.O. terminal (if compressor 1 fails to start), and terminal 1 on terminal block "C". If no voltage is read, replace the air compressor timer assembly Low output capacity of an air compressor Press the Reset switch to clear the System Pressure alarm, and watch the System Pressure Gauge. If, with the outlet flow at it's normal level, the system pressure falls below 15 PSIG, there is either an air leak in the unit, or the air compressor operating needs to be rebuilt. Let the unit run for 7.5 minutes and press the Reset switch again If the pressure falls below 15 PSIG, thoroughly check for air leaks in the unit using a soap/water solution If no leaks are found, install a maintenance kit in each air compressor. Note: A test gauge is available to confirm proper compressor output prior to installation in the dryer (testing can also be performed with the compressor installed in the dryer). Order Part Number MAINTENANCE & SPARE PARTS LISTS 8.1 MAINTENANCE KIT PART NO M Contains: PART NO. DESCRIPTION QTY Compressor Maintenance Kit Tower Outlet Filter Capillary Drain Kit SPARE PARTS. An inventory of the following spare parts should be kept on-hand for field servicing. PART NO. DESCRIPTION QTY C Sensor O-Ring Sensor Adaptor PARTS LIST PART NO. DESCRIPTION Power Lamp Start-Stop Switch 7378B Switch Heater Temperature Gauge B-101 System Pressure Gauge 4524 Outlet Pressure Gauge 3450 Alarm Lamp High Pressure Shut-Off Valve Air Flowmeter Compressor Check Valve Refrigeration Unit Drain Strainer B Fan Motor Fan Blade Precooler Air Compressor, ¾ HP 25PSI 4582 Vibration Mount 3986 Air Filter Element (Felts) Drain Capillary Kit Tower Solenoid Valve 4634 By-Pass Relief Valve Desiccant Tower (Front) Desiccant Tower (Rear) Tower Filter Alarm Plug (Male) Alarm Socket (Female) 3937 Boost Transformer Control Transformer Outlet Pressure Regulator D Humidity Sensor Sensor O-Ring 4157 Sensor Adaptor High/Low Pressure Alarm Switch M A System Pressure Alarm Switch Relay Tower Timer Override Switch Compressor Timer Reset Switch High/Low Pressure Alarm Relay Humidity Monitor Board Compressor Power Contactor 4582 Vibration Mount Comp. Power Contactor D Humidity Sensor 1 12

17 (Behind Cylinder) Item P/N Description Item P/N Description Item P/N Description Power Lamp Air Flowmeter Vibration Mount (8x) Power Switch Check Valve (2x) Air Filter Element (4x) 7378B Switch Heater Refrigeration Unit Drain Capillary Temperature Gauge Drain Strainer Tower Solenoid (2x) 4 B-101 System Pressure Gauge B Fan Motor (2x) By-Pass Relief Valve (2x) Outlet Pressure Gauge Fan Blade (2x) Dessicant Tower (Front) Alarm Lamp (3x) Precooler (2x) Dessicant Tower (Rear) High Pressure Shut-Off Air Compressor (2x) Tower Filter (2x) Figure 3 Front View 13

18 Item P/N Description Water Drain Outlet High Pressure Outlet Low Pressure Outlet Alarm Outlet Plug Alarm Outlet Socket (Not Shown) Figure 4 Rear View 14

19 Item P/N Description Desiccant Tower (Front) Desiccant Tower (Rear) Boost Transformer Control Transformer Outlet Pressure Regulator D Humidity Sensing Element Hi-Low Outlet Pressure Alarm Switch 8 M A System Pressure Alarm Switch Figure 5 Top View (Door Open) 15