iworx Side Application Wiring uide Pages ASM2 Sequence of peration & ypical Wiring 1 ALM2 Sequence of peration & ypical Wiring 2 U2 Sequence of peration, Flow iagram & ypical Wiring 3 - U3 Sequence of peration, Flow iagrams with Associated ontroller Wiring 5-1 U Sequence of peration, Flow iagrams with Associated ontroller Wiring 15-2 MPU2 Sequence of peration, Flow iagrams with Associated ontroller Wiring 25-35 VPU2 Sequence of peration, Flow iagrams with Associated ontroller Wiring - 6 VAV & VAVI Sequence of peration, ypical Multi-rop Network Wiring, hermostat onfiguration & ontroller rounding 7-8 VAV Application Wiring - 5 VAVI Application Wiring 55-60 atalog No. 500-2.0 Effective ate: ecember 1, 20 Supersedes ate: New
ASM2 Sequence of peration he controller provides outdoor temperature, outdoor humidity, indoor humidity, supply water temperature, energy monitoring readings, and unit enable status to other devices on the network. An input is provided to read an outside air temperature sensor. An additional input is provided to read an outside air humidity sensor. he current values of both sensors are made available to other devices on the network. he outdoor temperature and humidity are used to calculate the outdoor enthalpy. he enthalpy is required by certain types of controllers to determine if free cooling is available from the economizer. An additional input is provided to read an indoor air humidity sensor. he current value of the sensor can be used by other devices on the network as a global indoor humidity value, for calculating indoor enthalpy. An input is provided to read a supply water temperature sensor. he current value of the sensor is made available to other devices on the network. he supply water temperature is required by certain types of controllers to achieve automatic summer/winter changeover. A digital input is provided to read a contact closure for unit enable purposes. he ASM can make the status of that contact available to other devices on the network. ypically, unit enable information is utilized by heat pumps to determine when the water supply is flowing. he ASM can also monitor energy consumption. ne digital input accepts energy consumption pulses from a utility meter, another accepts a timing pulse from the utility. his pulse indicates the end of an energy-monitoring period, and implicitly signals the beginning of a new period. ypical ASM2 Level IV able Unit Enable End of Interval Signal Energy Monitoring Indoor umidity Water emp utside emp utside umidity 1 2 3 5 6 7 8 11 12 13 1 15 16 17 18 1 ASM2 NEA NEB M EN EMS M EM IA M SW A M A SA FF FF UI UI N UI7 N UI UI3 UI2 20 21 22 23 2 25 26 2 33 3 35 37 M 38 PWR 3 N 0 2VA lass 2 K ohm Precon ype III thermistor 2VA pilot relay or contactor coil V V signal utput Jumper Positions roup Sourcing Sinking 0- umidity 1
ALM2 Sequence of peration hermistors are used for temperature inputs. he ALM2 reads the sensor and converts it to temperature once every execution cycle. he converted value is made available as a network variable output. he temperature reading is compared to two threshold levels: an upper threshold and a lower threshold. If the reading is below the lower threshold or above the upper threshold then an alarm is generated. Four different detection methods are available by manipulating the threshold levels. isable temperature detection by disabling the input. he ALM2 also provides adjustable hysteresis on the threshold comparisons to prevent excessive alarm output jitter. here is one master hysteresis adjustment for all thermistor alarm detectors, while the upper and lower thresholds are adjustable for each input. he threshold and hysteresis adjustments are adjustable via the LI. ypical ALM2 Power Sourcing Level IV able * Alarm 8 Input * Alarm 7 Input * Alarm 6 Input * Alarm 5 Input * Alarm Input * Alarm 3 Input * Alarm 2 Input * Alarm 1 Input 1 2 3 5 6 7 8 11 12 13 1 15 16 17 18 1 ALM2 NEA NEB AS8 M AS7 AS6 M AS5 AS M AS3 AS2 M AS1 SA FF FF UI UI N UI7 N UI UI3 UI2 ALM8 78 ALM7 ALM6 56 ALM5 ALM 3 ALM3 ALM2 12 ALM1 M PWR N 20 21 22 23 2 25 26 2 33 3 35 37 38 3 0 Alarm 8 utput Alarm 7 utput Alarm 6 utput Alarm 5 utput Alarm utput Alarm 3 utput Alarm 2 utput Alarm 1 utput 2VA lass 2 * onnect switch or thermistor; switch stays in same position K ohm Precon ype III thermistor 2VA pilot relay or contactor coil V V signal utput Jumper Positions roup Sourcing Sinking 2
U2 Sequence of peration he U1 chiller controller is a stand-alone microprocessorbased controller for supervisory control of central chiller applications that utilize either an air-cooled chiller or a water-cooled centrifugal chiller with a cooling tower. wo chilled water pumps are configured for lead/lag operation. he U1 provides setpoint adjustment control of the chiller by integrating to the factory mounted chiller controls with a V setpoint control signal. For chilled water plant applications that utilize a cooling tower, the U1 controller provides control of the tower bypass valve and two cooling tower (condenser) pumps configured in a lead/ lag configuration. utputs are provided for control of the cooling tower bypass valve. Analog outputs are provided to support cooling tower applications with variable fan speed control. U1 control starts only if there is a cooling water demand and the outside air temperature (A) is above the A limits --> utoff temp. he U1 operates in conjunction with up to 60 controllers that can require chilled water (FU Series, U Series, PU Series). he cooling water demand is obtained by the U1 from controllers that have been grouped with the U1 at the LI user interface during initial configuration. ooling water demand can also be communicated through a digital input switch, or through a demand for chiller activation from the LI. Initial chiller control activates a chiller pump. he factory-installed chiller controls, as provided by the chiller manufacturer, detect water flow in the chilled water loop and activate the chiller. An anti-cycle function provides configurable chiller minimum n and ff times. he U1 includes support for two chilled water pumps, with only one pump required for normal operation. ne of the pumps is designated the lead pump, with the lag pump only being required in the event of a lead pump alarm. Each time the chiller is deactivated, the lead pump designation is transferred to the other pump. When the chiller is activated, the lead chiller pump is started. If the chiller pump has been commanded on for at least 20 seconds and the hiller Flow proof is off, an alarm is initiated and the lag pump is started. he lag pump also triggers an alarm if it has been commanded on for 20 seconds and flow proof is not established. If both chiller pumps fail, all outputs are turned off, all control stops, and a dual pump failure alarm is generated. Manual reset of the U1 controller from the operator interface or by cycling power to the U1 is required to restart control. he U1 also includes support for two condenser water pumps, with only one pump required for normal operation. ne of the pumps is designated the lead pump, with the lag pump only being required in the event of a lead pump failure. Each time the system is deactivated, the lead pump designation is transferred to the other pump. In a water-cooled chiller, when the chiller water pump is started the lead condenser pump is started also. If the condenser pump has been commanded on for at least 20 seconds and the condenser flow proof is off, an alarm is initiated and the lag pump is started. he lag pump also triggers an alarm if it has been commanded on for 20 seconds and flow proof is not established. If both condenser pumps fail, all outputs are turned off, all control stops, and a dual pump failure alarm is generated. Manual reset of the U1 controller from the operator interface or by cycling power to the U1 is required to restart control. An analog output is provided for setpoint adjustment utilizing the factory-mounted chiller controls. he chiller setpoint adjust feature of the U1 enables the user to change the chiller water supply setpoint through the LI. he bypass valve position is calculated by a Proportional + Integral (P+I) control loop based on the condenser water return temperature and the condenser water setpoint. he bypass valve control loop is activated 15 seconds after the condenser water flow proof has confirmed flow. As the temperature increases above the condenser water setpoint, the bypass valve is modulated open. he bypass valve is modulated closed as the water temperature decreases below the condenser setpoint. he cooling tower bypass valve control loop is selectable for direct or reverse acting operation. he cooling tower fan speed is calculated by a P+I control loop based on the condenser water return temperature and the cooling tower water setpoint. he fan speed control loop is activated 15 seconds after the cooling tower bypass valve has modulated to its 0% position (full flow through tower). As the temperature increases above the cooling tower water setpoint, the fan speed is increased. he fan speed is decreased as the water temperature decreases below the cooling tower setpoint. he fan speed control loop is selectable for direct or reverse acting operation. he U1 provides low limit control. When the outside air temperature (A) drops below the low limit setpoint as sensed by an ASM controller on the system network, the chiller water pump energizes and the chiller low limit output is enabled. he chiller low limit output is interfaced to the factory supplied chiller controls to signal the chiller to not start in response to the chiller water pump operation during the low limit condition. he chiller water pump and chiller low limit output de-energizes when the temperature rises 1 F above the low limit setpoint. A digital input is provided on the U1 to monitor the status of the chiller s general alarm. An alarm is reported to the LI when the chiller reports a general alarm condition. he U1 monitors the runtime of all four pumps, the chiller, and the fan. When any one of the runtimes exceeds a programmable limit, a maintenance alarm is reported to the LI. When the water temperatures exceed a programmable limit, a high limit alarm is reported to the LI. When the water temperature drops below a programmable limit, a low limit alarm is reported to the LI. When the water temperature returns to the proper range, a return to normal is generated. 3
hiller Flow iagram ooling ower A 2_33&3 ondenser UI 3_15&16 ooling ower Valve A 1_35& ondenser Pump 1 3_& ondenser Pump 2 _26& P ondenser Flow Proof UI 6_11&12 ondenser UI _1&15 hiller UI 1_18&1 hiller Flow Proof UI 5_12&13 P hiller Pump 1 1_& hiller Pump 2 2_2& hiller UI 2_17&18 LA Point ype & Number_erminal # & erminal # UI _5&6 Universal Input _erminals 5 & 6 hiller Setpoint A 3_&33 hiller Low 5_25&2 hiller eneral Alarm UI _5&6 ypical U2 Power Sourcing Level IV able hiller eneral Alarm hilled Water emand ondenser Flow Proof hiller Flow Proof ondenser emp ondenser emp hiller emp hiller emp 1 2 3 5 6 7 8 11 12 13 1 15 16 17 18 1 U2 NEA NEB ALM M W M FP M FP R M S WR M WS SA FF FF UI UI N UI7 N UI UI3 UI2 56 LL P2 3 P1 P2 12 P1 M F V M SP M PWR N 20 21 22 23 2 25 26 2 33 3 35 37 38 3 0 hiller Low indication ondenser Pump 2 ondenser Pump 1 hiller Pump 2 hiller Pump 1 V V V ooling ower ooling ower Valve hiller Setpoint 2VA lass 2 K ohm Precon ype III thermistor 2VA pilot relay or contactor coil utput Jumper Positions roup Sourcing Sinking V V signal
U3 Sequence of peration he controller maintains the temperature of a space to a userdefined setpoint. he control is achieved by controlling the economizer position and sequencing the heating and cooling stages or modulating the heating or cooling valves based on the current space requirements. he controller controls the starting and stopping of the supply air fan. he fan is energized when there is a need for heating or cooling. uring the occupied periods, the fan can be configured to run continuously. he fan can be overridden from the local thermostat. If overridden, the fan runs continuously. he enthalpies of the outside and inside air are calculated periodically. A comparison is performed to determine if free cooling is available. If free cooling is available, the economizer is enabled. Free cooling can also be enabled based on a dry-bulb comparison of the outdoor air temperature and indoor temperature. he system can use either a two position or modulated economizer. If a two-position economizer is employed. It is energized when there is a call for cooling. It is used as the first stage of cooling to take advantage of the energy savings. he two-position economizer output is off when the economizer feature is disabled. If a modulated economizer is employed, when free cooling is available the modulated economizer position is calculated by a Proportional + Integral (P+I) control loop. he control is based on the mixed air temperature and setpoint. As the temperature increases above the mixed air setpoint the economizer is modulated open. he economizer is modulated closed as the temperature decreases below the mixed air setpoint. he economizer is modulated to its minimum position when the economizer is disabled. he economizer can optionally be disabled during the unoccupied periods. When free cooling is available, mechanical cooling will not be enabled until the economizer is fully open (0%) for three minutes. In addition, the air temperature (SA) will be monitored and compared to the SA ooling. Should the SA fall below the SA ooling additional cooling will not be enabled. If the SA rises above the SA ooling additional cooling shall be enabled as needed. eating is accomplished through control of up to two stages of electric heating, or control of one floating point heating valve or control of one analog valve. ooling is accomplished through control of up to four stages of cooling, or one floating point cooling valve or control of one analog cooling valve. he heating and cooling stages are sequenced with a timed-proportioned control algorithm to minimize excessive cycling. he sequencing is based on the measured space temperature, space setpoint and the heating and cooling offsets. he heating and cooling offsets define a desired temperature range for occupied operation around the space setpoint. When unoccupied mode is entered, the heating setpoint is set back and the cooling setpoint is setup to a user-defined setpoint. he cooling stages are interlocked with the economizer control. If the two-position economizer is employed, the stages sequence on after the economizer. If configured for modulated analog valve the cooling valve position is calculated by a P + I control loop based on the space temperature and the cooling setpoint. As the temperature increases above the cooling setpoint, the cooling valve will be modulated open. he cooling valve will be modulated closed as the temperature decreases below the cooling setpoint. When unoccupied mode is entered, the cooling setpoint is setup. he heating valve position is calculated by a P+I control loop based on the space temperature and the heating setpoint. As the temperature decreases below the heating setpoint, the heating valve will be modulated open. he heating valve will be modulated closed as the temperature increases above the heating setpoint. When unoccupied mode is entered, the heating setpoint is set back. If configured for a floating point valve control the cooling valve is calculated by a P + I control loop based on the space temperature and cooling setpoint. As the temperature increases above the cooling setpoint, the valve will be modulated open. he valve will be modulated closed as the temperature decreases below the cooling setpoint. When unoccupied mode is entered, the cooling setpoint is setup. If configured for a floating point valve control the heating valve is calculated by a P + I control loop based on the space temperature and heating setpoint. As the temperature decreases below the heating setpoint, the valve will be modulated open. he valve will be modulated closed as the temperature increases above the heating setpoint. When unoccupied mode is entered, the heating setpoint is set back. Each controller interfaces to a local thermostat. he thermostat includes a space temperature sensor, temperature setpoint adjust, occupancy override, and a fan auto/on selection. Additionally a K Precon ype II or III thermistor / wall sensor can be used. he controller operates in one of two states: occupied or unoccupied. he LI determines the active operating mode. he controller maintains the comfort level to a user-defined setpoint during the occupied period. he controller uses setup and setback values during the unoccupied period to maintain the space temperature. An optional backup schedule is provided for cases when the LI is not available. A digital input is provided to monitor the fan proof. If the fan is energized and no air flow is detected after seconds, the controller turns off all stages of heating and cooling along with the supply air fan. he controller returns to normal operation after it is reset. An alarm is reported to the LI when this condition exists. A digital input is provided on the controller to monitor the status of the air filter. An external pressure switch is wired to the input to determine when the filter becomes dirty. An alarm is reported to the LI when this condition exists. air low limit protection is provided through a digital input. If a low limit condition exists, the controller turns off all stages of heating and cooling along with the supply air fan. An alarm is reported to the LI when this condition exists. If configured for either analog or floating point valve the valve will open 0% to prevent freezing of the coils. he controller returns to normal operation after it is reset. Following the reset there is a minute delay before the mixed air low limit is checked again. he controller monitors the runtime of the cooling stages, heating stages, and fan. When any of the runtimes exceeds the programmable limit, a maintenance alarm is reported to the LI. When the space temperature exceeds a programmable limit, a high limit alarm is reported to the LI. When the space temperature drops below a programmable limit, a low limit alarm is reported to the LI. When the space temperature returns to the proper range, a return to normal alarm is reported to the LI. When the return air humidity rises above the humidity setpoint, dehumidification is enabled by enabling the cooling stages, if modulated cooling is enabled; the cooling output goes to 0%. ehumidification is disabled, when return air humidity drops below the setpoint by 3%. 5
Single Zone Unit with Staged eating & ooling and Modulated ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating Stage 2 6_23&2 ooling Stage 2 2_2& ooling Stage _26& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 eating Stage 1 5_2&25 ooling Stage 1 1_& ooling Stage 3 3_& UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Staged eating & ooling and Modulated ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity 1 2 3 5 6 7 8 11 12 13 1 15 16 17 18 1 K ohm Precon ype III thermistor V U3 2VA pilot relay or contactor coil V signal NEA NEB SA M FNP M S RA M MLL M FIL SMK M SA MA M RA 0- umidity SA FF FF UI UI N N UI7 UI UI3 UI2 E 78 FAN 2 56 1 3 3 2 12 1 M LM M M ENM M PWR N 20 21 22 23 2 25 26 2 33 3 35 37 38 3 0 utput Jumper Positions roup Sourcing Sinking eating Stage 2 eating Stage 1 ooling Stage ooling Stage 3 ooling Stage 2 ooling Stage 1 V Modulated 2VA lass 2 6
Single Zone Unit with Modulated eating, ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil A 1_35& ooling oil A 2_3&33 Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 S0 series Single Zone Unit with Modulated eating, ooling and ; riac utputs Wired as Power Sourced Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 5 M FNP 56 1 2 25 6 M 26 7 S UI 8 RA UI 3 3 M 2 12 1 2 11 MLL 12 M UI7 13 FIL M 33 1 SMK V Modulated ooling LM 3 15 M M 35 V Modulated eating 16 SA UI M 17 MA 37 V Modulated UI3 ENM 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor 0- umidity V U3 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 7
Single Zone Unit with Floating Point eating, ooling and Modulated ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil Valve pen 5_2&25 eating oil Valve lose 6_23&2 ooling oil Valve pen 1_& ooling oil Valve lose 2_2& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Floating Point eating, ooling and Modulated ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 eating Valve lose 5 M FNP 56 1 2 25 eating Valve pen 6 M 26 7 S UI 3 8 RA UI 3 M 2 12 1 2 ooling Valve lose ooling Valve pen 11 MLL 12 M UI7 13 FIL 1 SMK M LM 33 3 15 M M 35 16 SA M UI 17 V MA UI3 ENM 37 18 M UI2 M 38 Modulated 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 8
Single Zone Unit with Staged eating, Modulated ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 UI 5_12&13 Low UI 6_11&12 eating Stage 1 5_2&25 eating Stage 2 6_23&2 ooling oil A 2_3&33 Start Stop 7_21&22 UI_5&6 etector UI _1&15 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Staged eating, Modulated ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 M 56 2 eating Stage 2 5 FNP 5 eating Stage 1 6 M 26 7 S UI 8 RA UI 3 3 M 2 12 1 2 11 MLL 12 M UI7 13 FIL M 33 1 V SMK Modulated ooling LM 3 15 M M 35 16 SA M UI 17 MA V 37 Modulated UI3 ENM 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking
Single Zone Unit with Staged eating, Floating Point ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 UI 5_12&13 Low UI 6_11&12 eating Stage 1 5_2&25 eating Stage 2 6_23&2 ooling oil Valve pen 1_& ooling oil Valve lose 2_2& UI_5&6 Start Stop 7_21&22 etector UI _1&15 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Staged eating, Floating Point ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 M 56 2 eating Stage 2 5 FNP 5 eating Stage 1 6 M 26 7 S UI 8 RA UI 3 3 M 2 12 1 2 ooling Valve lose ooling Valve pen 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M M 35 16 SA M UI 17 MA V 37 Modulated UI3 ENM 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking
Single Zone Unit with Modulated eating, Staged ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 ooling Stage 2 2_2& ooling Stage _26& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 eating oil A 1_35& ooling Stage 1 1_& ooling Stage 3 3_& UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Modulated eating, Staged ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 M 56 2 5 26 FNP 5 6 M ooling Stage 7 S UI 8 RA UI 3 3 ooling Stage 3 M 2 12 1 2 ooling Stage 2 ooling Stage 1 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M M 35 V Modulated eating 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 11
Single Zone Unit with Modulated eating, Floating Point ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 ooling oil Valve lose 2_2& ooling oil Valve pen 1_& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 eating oil A 1_35& UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Modulated eating, Floating Point ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 5 M FNP 56 1 2 25 6 M 26 7 S UI 8 RA UI 3 3 M 2 12 1 2 ooling Valve lose ooling Valve pen 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M V Modulated eating M 35 16 SA M UI V 17 MA Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 12
Single Zone Unit with Floating Point eating, Modulated ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil Valve lose 6_23&2 ooling oil A 2_3&33 Start Stop 7_21&22 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 UI 5_12&13 eating oil Valve pen 5_2&25 UI_5&6 etector UI _1&15 Single Zone Unit with Floating Point eating, Modulated ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof emp Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 eating Valve lose 5 M FNP 56 1 2 25 eating Valve pen 6 M 26 7 S UI 8 RA UI 3 3 M 2 12 1 2 11 MLL 12 M UI7 13 FIL M 33 1 SMK V Modulated ooling LM 3 15 M M 35 16 SA M UI 17 MA 37 V Modulated UI3 ENM 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 13
Single Zone Unit with Floating Point eating, Staged ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 UI 8_8& ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil Valve lose 6_23&2 ooling Stage 2 2_2& ooling Stage _26& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 UI 5_12&13 eating oil Valve pen 5_2&25 ooling Stage 1 1_& ooling Stage 3 3_& UI_5&6 etector UI _1&15 Single Zone Unit with Floating Point eating, Staged ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof Low emp emp umidity E 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 eating Valve lose 5 M FNP 56 1 2 25 eating Valve pen 6 M 26 7 S UI 3 ooling Stage 8 RA UI 3 ooling Stage 3 M 2 12 2 ooling Stage 2 1 ooling Stage 1 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U3 0- umidity 2VA pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 1
U Sequence of peration he controller maintains the temperature of a space to a userdefined setpoint. he figure below illustrates a typical controller application. he control is achieved by sequencing the heating and cooling stages or modulating heating or cooling valves based on the current space requirements. he controller controls the starting and stopping of the supply air fan. he fan is energized when there is a need for heating or cooling. uring the occupied periods, the fan can be configured to run continuously. he fan can be overridden from the local thermostat. If overridden, the fan runs continuously. he enthalpies of the outside and inside air are calculated periodically. A comparison is performed to determine if free cooling is available. If free cooling is available, the economizer is enabled. Free cooling can also be enabled based on a dry-bulb comparison of the outdoor air temperature and indoor temperature. If the modulated economizer is enabled, when free cooling is available, the modulated economizer position is calculated by a Proportional + Integral (P+I) control loop. he control is based on the mixed air temperature and setpoint. As the temperature increases above the mixed air setpoint, the economizer valve is modulated open. he economizer is modulated closed as the temperature decreases below the mixed air setpoint. he economizer is modulated to its minimum position when the economizer is disabled. he economizer can optionally be disabled during unoccupied periods. When free cooling is available, mechanical cooling will not be enabled until the economizer is fully open (0%) for three minutes. eating is accomplished through control of up to two stages of heating, control of a floating point heating valve or control of one analog valve. ooling is accomplished through control of up to two stages of cooling, a floating point cooling valve or an analog cooling valve. he heating and cooling stages are sequenced with a time-proportioned control algorithm to minimize excessive cycling. he sequencing is based on the measured space temperature, space setpoint and the heating and cooling offsets. he heating and cooling offsets define a desired temperature range for occupied operation around the space setpoint. When unoccupied mode is entered, the heating setpoint is set back and the cooling setpoint is set to a user defined setpoint. he cooling stages are interlocked with the economizer control. If configured for modulated analog valve, the cooling valve position is calculated by a Proportional + Integral control loop based on the space temperature and the cooling setpoint. As the temperature increases above the cooling setpoint, the cooling valve will be modulated open. he cooling valve will be modulated closed as the temperature decreases below the cooling setpoint. When unoccupied mode is entered, the cooling setpoint is set up. he heating valve position is calculated by a Proportional + Integral control loop based on the space temperature and the heating setpoint. As the temperature decreases below the heating setpoint, the heating valve will be modulated open. he heating valve will be modulated closed as the temperature increases above the heating setpoint. When unoccupied mode is entered, the heating setpoint is set back. If configured for a floating point valve control, the cooling valve is calculated by a Proportional + Integral control loop based on the space temperature and cooling setpoint. As the temperature increases above the cooling setpoint, the valve will be modulated open. he valve will be modulated closed as the temperature decreases below the cooling setpoint. When unoccupied mode is entered, the cooling setpoint is setup. If configured for a floating point valve control, the heating valve is calculated by a Proportional + Integral control loop based on the space temperature and heating setpoint. As the temperature decreases below the heating setpoint, the valve will be modulated open. he valve will be modulated closed as the temperature increases above the heating setpoint. When unoccupied mode is entered, the heating setpoint is setup. Each controller interfaces to a local thermostat. he thermostat includes a space temperature sensor, temperature setpoint adjustment, occupancy override, and a fan auto/on selection (depending on the model). Additionally a K Precon ype II or ype III hermistor / wall sensor can be used. he controller operates in one of two states: occupied or unoccupied. he LI determines the active operating mode. he controller maintains the comfort level to a user-defined setpoint during the occupied period. he controller uses setup and setback values during the unoccupied period to maintain the space temperature. An optional backup schedule is provided for cases when the LI is not available. A digital input is provided to monitor the status of the supply air fan. If the fan is energized and no air flow is detected after seconds, the controller turns off all stages of heating and cooling along with the supply air fan. he controller returns to normal operation after it is reset. An alarm is reported to the LI when this condition exists. he controller monitors a digital input to determine the presence of smoke. When the input indicates smoke, the controller immediately turns off the supply air fan and all stages of heating and cooling. he controller returns to normal operation after it is reset. An alarm is reported to the LI when smoke is detected. A digital input is provided on the controller to monitor the status of the air filter. An external pressure switch is wired to the input to determine when the filter becomes dirty. An alarm is reported to the LI when this condition exists. air low limit protection is provided through a digital input. If a low limit condition exists, the controller turns off all stages of heating and cooling along with the supply air fan. An alarm is reported to the LI when this condition exists. If configured for either analog or floating point valve the valve will open 0% to prevent freezing of the coils. he controller returns to normal operation after it is reset. Following the reset, there is a minute delay before the mixed air low limit is checked again. An indoor air quality input is provided. If an indoor air quality alarm is indicated, the supply air fan is energized and the economizer is overridden to supply fresh air to the space. he controller monitors the runtime of the cooling stages, heating stages, and fan. When any of the runtimes exceeds a programmable limit, a maintenance alarm is reported to the LI. When the space temperature exceeds a programmable limit, a high limit alarm is reported to the LI. When the space temperature drops below a programmable limit, a low limit alarm is reported to the LI. When the space temperature returns to the proper range, a return to normal alarm is reported to the LI. When the return umidity or Zone umidity rises above the humidity setpoint, dehumidification is enabled by enabling the cooling stages, if modulated cooling is enabled, the cooling output goes to 0%. ehumidification is disabled, when return air humidity drops below the setpoint by 3%. When the umidity or Zone umidity falls below the umid Setpoint Low, humidification is turned on and turns off when it is 1% above setpoint. 15
Single Zone Unit with Staged eating & ooling and Modulated ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating Stage 2 6_23&2 ooling Stage 2 2_2& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 eating Stage 1 5_2&25 ooling Stage 1 1_& UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Staged eating & ooling and Modulated ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity 1 2 3 5 6 7 8 11 12 13 1 15 16 17 18 1 K ohm Precon ype III thermistor V U NEA NEB SA M FNP M S SA M MLL M FIL SMK M SA MA M RA 0- umidity 2VA lass 2 pilot relay or contactor coil V signal SA FF FF UI UI N N UI7 UI UI3 UI2 FR 78 FAN 2 56 1 RV 3 RV 2 12 1 M LM M M ENM M PWR N 20 21 22 23 2 25 26 2 33 3 35 37 38 3 0 utput Jumper Positions roup Sourcing Sinking eating Stage 2 eating Stage 1 ooling Stage 2 ooling Stage 1 V Modulated 2VA lass 2 16
Single Zone Unit with Modulated eating, ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil A 1_33&3 ooling oil A 2_&33 Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Modulated eating, ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 5 M FNP 56 1 2 25 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 1 2 11 MLL 12 M UI7 13 FIL M 33 1 SMK V Modulated ooling LM 3 15 M M 35 V Modulated eating 16 SA UI M 17 MA 37 V Modulated UI3 ENM 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor 0- umidity 2VA lass 2 pilot relay or contactor coil V signal V U utput Jumper Positions roup Sourcing Sinking 17
Single Zone Unit with Floating Point eating, ooling and Modulated ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil Valve pen 5_2&25 eating oil Valve lose 6_23&2 ooling oil Valve pen 1_& ooling oil Valve lose 2_2& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Floating Point eating, ooling and Modulated ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 eating Valve lose 5 M FNP 56 1 2 25 eating Valve pen 6 M RV 26 7 S UI 3 8 SA UI RV M 2 12 1 2 ooling Valve lose ooling Valve pen 11 MLL 12 M UI7 13 FIL 1 SMK M LM 33 3 15 M M 35 16 SA M UI 17 MA V UI3 ENM 37 18 M UI2 M 38 Modulated 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 18
Single Zone Unit with Staged eating, Modulated ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 UI 5_12&13 Low UI 6_11&12 eating Stage 1 5_2&25 eating Stage 2 6_23&2 ooling oil A 2_&33 Start Stop 7_21&22 UI_5&6 etector UI _1&15 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 S0 series Single Zone Unit with Staged eating, Modulated ooling and ; riac utputs Wired as Power Sourced Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 M 56 2 eating Stage 2 5 FNP 5 eating Stage 1 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 1 2 11 MLL 12 M UI7 13 FIL M 33 1 SMK V Modulated ooling LM 3 15 M M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 1
Single Zone Unit with Staged eating, Floating Point ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 UI 5_12&13 Low UI 6_11&12 eating Stage 1 5_2&25 eating Stage 2 6_23&2 ooling oil Valve pen 1_& ooling oil Valve lose 2_2& UI_5&6 Start Stop 7_21&22 etector UI _1&15 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Staged eating, Floating Point ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 M 56 2 eating Stage 2 5 FNP 5 eating Stage 1 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 1 2 ooling Valve lose ooling Valve pen 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 20
Single Zone Unit with Modulated eating, Staged ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 ooling Stage 2 2_2& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 eating oil A 1_33&3 ooling Stage 1 1_& UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Modulated eating, Staged ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 5 M FNP 56 1 2 25 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 1 2 ooling Stage 2 ooling Stage 1 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M V Modulated eating M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 21
Single Zone Unit with Modulated eating, Floating Point ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 ooling oil Valve lose 2_2& ooling oil Valve pen 1_& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& UI 5_12&13 eating oil A 1_33&3 UI_5&6 etector UI _1&15 Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 Single Zone Unit with Modulated eating, Floating Point ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 5 M FNP 56 1 2 25 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 1 2 ooling Valve lose ooling Valve pen 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M V Modulated eating M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 22
Single Zone Unit with Floating Point eating, Modulated ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil Valve lose 6_23&2 ooling oil A 2_&33 Start Stop 7_21&22 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 UI 5_12&13 eating oil Valve pen 5_2&25 UI_5&6 etector UI _1&15 Single Zone Unit with Floating Point eating, Modulated ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 eating Valve lose 5 M FNP 56 1 2 25 eating Valve pen 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 1 2 11 MLL 12 M UI7 13 FIL M 33 1 SMK V Modulated ooling LM 3 15 M M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 23
Single Zone Unit with Floating Point eating, Staged ooling and ; riac utputs Wired as Power Sourced 2 UI 7_& umidity UI 1_18&1 ontrol A 0_37& UI 2_17&18 Low UI 6_11&12 eating oil Valve lose 6_23&2 ooling Stage 2 2_2& Start Stop 7_21&22 UI 3_15&16 Zone SA_3& Point ype & Number_erminal # & erminal # UI 1_18&1 Universal Input 1_erminals 18 & 1 UI 5_12&13 eating oil Valve pen 5_2&25 ooling Stage 1 1_& UI_5&6 etector UI _1&15 Single Zone Unit with Floating Point eating, Staged ooling and ; riac utputs Wired as Power Sourced S0 series Level IV able Proof umidity Low emp emp umidity FR 20 1 NEA 78 21 2 NEB FAN 22 3 SA SA 2 23 eating Valve lose 5 M FNP 56 1 2 25 eating Valve pen 6 M RV 26 7 S UI 8 SA UI 3 RV M 2 12 2 ooling Stage 2 1 ooling Stage 1 11 MLL 12 M UI7 13 FIL M 33 1 SMK LM 3 15 M M 35 16 SA M UI 17 MA V Modulated UI3 ENM 37 18 M UI2 M 38 1 RA PWR 3 2VA lass 2 N 0 K ohm Precon ype III thermistor V U 0- umidity 2VA lass 2 pilot relay or contactor coil V signal utput Jumper Positions roup Sourcing Sinking 2
MPU2 Sequence of peration he MPU2 is a multiplexed package unit controller that permits a single zone package unit to operate multiple zones. he two figures on page illustrate typical MPU2 applications. he MPU2 operates in conjunction with up to multiplexed zone controllers. he control is achieved by multiplexing the primary supply air between cooling and heating based on the various demands from the Zone ontrollers. In addition to multiplexing, the MPU2 controls an economizer and bypass damper. he starting and stopping of the supply air fan is controlled by the MPU2. he fan is energized when there is a call for heating or cooling from the Zone ontrollers. uring the occupied periods, the fan can be configured to run continuously. he enthalpies of the outside and inside air are calculated periodically. A comparison is performed to determine if free cooling is available. If free cooling is available, the economizer is enabled. ptionally, free cooling can be determined by a dry bulb comparison of the outside air temperature and average zone temperature. he economizer can be configured as two-position (digital) or modulated (analog). If enabled, the two position economizer output is energized when there is a call for cooling. It is used as the first stage of cooling to take advantage of the energy savings. he twoposition economizer output is off when the economizer is disabled. When free cooling is available, the modulated economizer position is calculated by a Proportional + Integral (P+I) control loop based on the mixed air temperature and setpoint. As the temperature increases above the mixed air setpoint, the economizer damper is modulated open. he economizer is modulated closed as the temperature decreases below the mixed air setpoint. he economizer is modulated to its minimum position when the economizer is disabled. he economizer can optionally be disabled during unoccupied periods. he bypass damper operates to maintain a configurable system static pressure setpoint. he bypass damper position is calculated by a Proportional + Integral (P+I) control loop based on the measured static pressure and setpoint. As the pressure increases above the pressure setpoint, the bypass damper is modulated open. he bypass damper is modulated closed as the pressure decreases below the pressure setpoint. eating and cooling changeover setpoints are provided to prevent zone thermal shock during mode changes. he bypass damper operates to maintain a configurable system static pressure setpoint. he bypass damper position is calculated by a Proportional + Integral (P+I) control loop based on the measured static pressure and setpoint. As the pressure increases above the pressure setpoint, the bypass damper is modulated open. he bypass damper is modulated closed as the pressure decreases below the pressure setpoint. eating and cooling changeover setpoints are provided to prevent zone thermal shock during mode changes. An indoor air quality input is provided to monitor the Indoor Quality (). It can accept a digital 2 sensor providing a contact closure, or an analog 2 sensor. In addition, an alarm condition can be signaled by one of the Zone ontrollers. When an alarm condition exists, the MPU2 energizes the supply air fan and overrides the static pressure setpoint to the alarm setpoint. he economizer is overridden to the minimum ventilation position. After a programmable time delay, the economizer is overridden open to supply fresh air to the zones. ptional heating and cooling outside air temperature lockouts are provided for the economizer. If the sensor is connected directly, an alarm is reported to the LI and all of the Zone ontrollers. he MPU2 scans all associated Zone ontrollers to collect system demand data. he total heating and cooling demands are accumulated. he greatest demand determines the control mode. When the system cooling demand is greater than the system heating demand, the system enters the cooling mode. When the system heating demand is greater than the system cooling demand, the system enters the heating mode. eating is accomplished through control of up to two stages of electric heating, or control of one floating point heating valve or control of one analog output (valve or variable speed circulator). ooling is accomplished through control of up to four stages of cooling, or one floating point cooling valve or control of one analog cooling output (valve or variable speed circulator). he cooling stages are sequenced with a timed-proportioned control algorithm to minimize excessive cycling. he sequencing is based on the measured supply air temperature, and the cooling setpoint. he cooling and heating demands are continually re-evaluated during the cooling mode of operation. he controller is capable of switching to the heating mode when the temperature demand is greater for heating. he cooling stages are interlocked with the economizer control. If the two-position economizer is employed, the stages sequence on after the economizer. he heating stages are sequenced with a timed-proportioned control algorithm to minimize excessive cycling. he sequencing is based on the measured supply air temperature, and the heating setpoint. he cooling and heating demands are continually re-evaluated during the heating mode of operation. he controller is capable of switching to the cooling mode when the temperature demand is greater for cooling. If configured for modulated analog output (valve or variable speed circulator) the cooling output position is calculated by a P + I control loop based on the supply temperature and the cooling setpoint. As the temperature increases above the cooling setpoint, the cooling output will be modulated open. he cooling output will be modulated closed as the temperature decreases below the cooling setpoint. he heating output (valve or variable speed circulator) position is calculated by a P + I control loop based on the supply temperature and the heating setpoint. As the temperature decreases below the heating setpoint, the heating output will be modulated open. he heating output will be modulated closed as the temperature increases above the heating setpoint. If configured for a floating point valve control, the cooling valve is calculated by a P + I control loop based on the supply temperature and cooling setpoint. As the temperature increases above the cooling setpoint, the valve will be modulated open. he valve will be modulated closed as the temperature decreases below the cooling setpoint. If configured for a floating point valve control, the heating valve is calculated by a P + I control loop based on the supply temperature and cooling setpoint. As the temperature decreases below the heating setpoint, the valve will be modulated open. he valve will be modulated closed as the temperature increases above the heating setpoint. In both the heating and cooling modes, the supply air temperature setpoint may be reset by the greatest zone temperature. he controller optionally has the capability of monitoring the supply air temperature to determine if the heating and cooling are operating properly. uring the cooling mode, if the supply air temperature fails to drop below the cooling operational limit after a pre-determined time period, the cooling stages shut down and a cooling failed alarm is reported to the LI. 25