T8034C Heating/Cooling Thermostats INSTALLATI INSTUCTIS APPLICATI These T8034C Thermostats control 4 to 30 Vac singlestage heating-cooling systems. An spdt mercury switch makes (H) to on temperature fall for heating, and (C) to on temperature rise for cooling. Integral switches control -- system operation and - or - fan operation. Heat anticipation is adjustable, 0.8A to.0a. See Fig.. Includes dual Celsius/Fahrenheit temperature scale. MECU NOTICE If this control is replacing a control that contains mercury in a sealed tube, do not place your old control in the trash. Dispose of properly. Contact your local waste management authority for instructions regarding recycling and the proper disposal of an old control. MOUNTIN HOLE (THEMOSTAT TO ALL O OUTLET BOX) BIMETAL ELEMENT BEHIND SCALE..8.5 L O N.3.35 ADJUSTABLE INDICATO.9.7.5 FAN MOUNTIN HOLE TEMPEATUE SETTIN LEVE M560 Fig.. Internal view of the T8034C. INSTALLATI hen Installing this Product. ead these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.. Check the ratings given in the Instructions and on the product to make sure the product is suitable for your application. 3. Installer must be a trained, experienced service technician. 4. After installation is complete, check out product operation as provided in these Instructions. CAUTI Can cause electrical shock or equipment damage. Disconnect power supply before beginning installation. Location Locate the thermostat about 5 ft (.5m) above the floor on an inside wall in an area with good air circulation at average temperature. Do not mount the thermostat where it can be affected by: drafts or dead spots behind doors or in corners. hot or cold air from ducts. radiant heat from the sun, fireplaces or appliances. unheated (uncooled) areas such as outside walls behind the thermostats. This thermostat is a precision instrument and was carefully adjusted at the factory. Handle it carefully. Mounting and iring Disconnect power supply before beginning installation to prevent electrical shock or equipment damage. All wiring must comply with local codes and ordinances. The T8034C can be mounted directly on a wall or horizontal outlet box. Use Honeywell part no. 0058 Horizontal allplate (beige) to cover mounting marks left by the old thermostat, or use Honeywell part no. 93A Mounting Plate Assembly (beige) to mount on vertical outlet box or to cover wall marks where larger plate is needed. Order the horizontal wallplate or mounting plate assembly separately. U.S. egistered Trademark Copyright 00 Honeywell All ights eserved X-XX UL 69-598
T8034C IN/IN THEMOSTATS If the 0058 Horizontal allplate is used, align the thermostat and wallplate (see Fig. ) and press firmly together until the wallplate snaps in place; then wire and mount the thermostat. If the 93A Mounting Plate Assembly is used, review the instructions provided with the assembly before wiring and mounting the thermostat. UP Heat Off Cool On FAN Auto 90 80 70 60 3. Connect the wires to the terminals on the back of the thermostat. See Fig. 3. For internal schematic and typical hookup diagram, see Fig. 4 through 9. 4. emove the thermostat cover by pulling outward on the right edge of cover until it snaps free of the thermostat base. Carefully remove and discard the foam plastic shipping insert that protects the switch and bimetal assembly during shipping. 5. Set the adjustable heat anticipator indicator to match the current draw of the primary heating control (see Heat Anticipator Setting). 6. Push excess wire back through the hole and plug any opening with insulation to prevent drafts that may affect thermostat performance. 7. Loosely fasten the thermostat (with wallplate, if applicable) to the wall or outlet box with a screw through the left mounting hole. Adjust the thermostat so that it is approximately level and fasten the second screw through the right mounting hole. Do not tighten. 8. For optimum performance, level the thermostat using a spirit level or plumb line. Tighten the mounting screws. 9. eplace the thermostat cover. JUMPE M087 H Fig.. Mount the T8034C Thermostat on 0058 allplate. IMPOTANT An incorrectly leveled thermostat causes inaccurate temperature control. C To wire and mount thermostat:. In replacement applications, check the existing thermostat wires for cracked or frayed insulation. eplace any wires in poor condition. If the wire is plastered into the wall, make a hole next to the wires and loosen the wires so that they can be pushed back into the wall later.. In new installations, run wiring (if necessary) to the thermostat location. JUMPE NOT SUPPLIED ITH THEMOSTAT. M330 Fig. 3. hen using T8034C with H and C terminals in single transformer system, jumper H, C terminals. FAN C CTACTO L H ELA L POE SUPPL. POVIDE DISCNECT MEANS AND OVELOAD POTECTI AS EQUIED. JUMPE C, H TEMINALS FO SINLE TANSFOME. M4A Fig. 4. Internal schematic and typical hookup for T8034C in heating-cooling system with separate heating-cooling transformers or single transformer. 69-598
T8034C IN/IN THEMOSTATS FAN L CTACTO ELA POE SUPPL. POVIDE DISCNECT MEANS AND OVELOAD POTECTI AS EQUIED. JUMPE - FO AS O OIL FOCED AM AI IN ITH CVENTIAL IN. JUMPE - FO CENTAL ELECTIC IN ITH CVENTIAL IN. IF JUMPE IS NOT CNECTED THEMOSTAT ILL NOT ENEIZE FAN IN POSITI. M034F Fig. 5. Internal schematic and typical hookup for T8034C in gas- or oil-fired or central electric heat systems. L FAN P O DEFOST ELA CHANEOVE ELA () ELA CTACTO CHANEOVE ELA () B POE SUPPL. POVIDE DISCNECT MEANS AND OVELOAD POTECTI AS EQUIED. M97 Fig. 6. Internal schematic and typical hookup for T8034C with terminal for defrost relay in heat pump system. 3 69-598
T8034C IN/IN THEMOSTATS FAN O CHANEOVE ELA () L POE SUPPL. POVIDE DISCNECT MEANS AND OVELOAD POTECTI AS EQUIED. JUMPE - FO AS O OIL FOCED AM AI IN ITH CVENTIAL IN. JUMPE - FO CENTAL ELECTIC IN ITH CVENTIAL IN O SINLE STAE PUMP APPLICATIS. IF JUMPE IS NOT CNECTED, THEMOSTAT ITH NOT ENEIZE FAN IN POSITI. 3 JUMPE - FO SINLE STAE PUMP APPLICATIS. M33C 3 B ELA CHANEOVE ELA () ELA Fig. 7. Internal schematic and typical hookup for T8034C in single transformer heating-cooling system. TEMP FALL FAN L ELA CTACTO POE SUPPL. POVIDE DISCNECT MEANS AND OVELOAD POTECTI AS EQUIED M54 Fig. 8. Internal schematic and typical hookup for T8034C in single transformer heating-cooling systems. 69-598 4
T8034C IN/IN THEMOSTATS 4 FAN ELA L 5 B O CHANEOVE ELA () CHANEOVE ELA () POE SUPPL. POVIDE DISCNECT MEANS AND OVELOAD POTECTI AS EQUIED. ELA M333 Fig. 9. Heat Pump iring for T8034C. SETTIN AND ADJUSTMENT System and Fan Switching The T8034C features and FAN switches for control of the heating-cooling and fan systems. The switch controls system operation as follows: : Only heating system operates. : Both heating and cooling systems are off. : Only cooling system operates. The FAN switch controls fan operation as follows: : In standard systems, fan operates in response to the thermostat in cooling; fan operates in response to the plenum fan control in heating. In heat pump or electric heat systems, the fan operates in response to the thermostat in heating and cooling. : The fan runs continuously. To switch positions, slide the lever to the desired position. Place the switch lever directly over the desired indicator mark for proper circuit operation. Heat Anticipator Setting IMPOTANT The T8034C Thermostat has an adjustable heat anticipator and operates properly L IF THE IS ADJUSTED TO MATCH THE CUENT DA OF THE PIMA C- TOL. Use this thermostat only on systems with current draws that fall within the range of the heat anticipator. Do not use this device on Powerpile (millivolt) systems. If the current rating is not available:. Turn off the power.. ire the thermostat, but do not mount it on the wall. 3. Connect an ammeter between the wire and terminal on the thermostat (in series with the primary control). 4. Prepare the system for operation. 5. Turn on the power. 6. Turn the system switch to heat. 7. Increase the thermostat setpoint as necessary to get the system operating. 8. ith the system operating through the ammeter, wait one minute, then read the ammeter. 9. Turn the system switch to, and turn off the power. 0. Adjust the heat anticipator to match the reading on the ammeter.. Disconnect the ammeter, reconnect the wire, and mount the thermostat. Continue with system checkout. The heat anticipator could require further adjustment for best performance. To lengthen the burner-on time, move the indicator in the direction of the longer arrows not more than one-half scale marking at a time. To shorten the burner-on time, move the indicator in the opposite direction. Most one-stage heating equipment is designed to operate at five to six cycles per hour, at 50 percent load conditions. hen using a T8034 Thermostat in heat pump systems, set the heat anticipator at 40 percent of the actual primary control current draw to reduce the cycling rate. Most heat pump systems should cycle -/ to 3 times per hour. A current rating is usually stamped in the nameplate of the primary control. Set the adjustable heat anticipator indicator to match the value given on the nameplate. 5 69-598
T8034C IN/IN THEMOSTATS CHECKOUT CAUTI Can cause damage to heat anticipator. Do not check operation by shorting across terminals of system controls. IMPOTANT To assure accurate temperature control, do not touch or breathe on bimetal or thermometer. Heating ith system switch set at and fan switch at, move the temperature setting lever about 0 F (6 C) above the room temperature. In standard systems, the heating should start and the fan should start after a short delay. In heat pump or electric heat systems, both the heating and fan should start. Move the temperature setting lever about 0 F (6 C) below the room temperature. In standard systems, the heating should shut off and the fan should shut off after a short delay. In heat pump or electric heat systems, both the heating and fan should shut off. IN NOTE: CAUTI Can cause damage to compressor. Do not operate cooling if outdoor temperature is below 50 F (0 C). efer to manufacturer recommendations. To prevent compressor short cycling, some manufacturer equipment includes a minimum offtimer to provide a five-minute time delay before activating the compressor when the thermostat last turned the compressor off, or from when the system first received power. This delay protects the compressor. ith the system switch set at and fan switch at, move the temperature setting lever about 0 F (6 C) below the room temperature. Cooling and fan should start (see NOTE in IN section). Move the temperature setting lever about 0 F (6 C) above the room temperature. Cooling and fan should shut off. Fan ith the system switch set at, and the fan switch at, the fan should run continuously. Move the fan switch to. In standard systems, fan operation is controlled by the plenum fan control in heating and by the thermostat in cooling. In heat pump or electric heat systems, fan operation is controlled by the thermostat in heating and cooling. ecalibration These thermostats are calibrated at the factory and should not need recalibration. If the thermostat needs adjustment, first check for accurate leveling. To check calibration:. Move the temperature setting lever to the lower end of the temperature scale. System switch must be placed in the position. ait at least five minutes.. emove the thermostat cover. Move the setting lever until the switch just makes contact. The mercury in the switch rolls to the left end of the tube. 3. eplace the cover and wait five minutes for the cover and the thermostat to lose the heat gained from your hands. If the thermometer pointer and the setting lever indicator read approximately the same, no recalibration is needed. If recalibration is necessary:. Place the temperature setting lever at the same setting as the thermometer. emove the cover by pulling outward on right edge of cover until it snaps free of the thermostat base.. Insert 04994A Calibration rench (ordered separately) onto the hex nut under the coil. See Fig. 9. Hold the setting lever so it does not move and turn the wrench clockwise until the mercury rolls to the right end of the tube. emove the wrench and replace the cover. NOTE: To assure accurate temperature control, do not touch or breathe on bimetal or thermometer. 3. Move the setting lever to a low setting. ait at least five minutes for the temperature to stabilize. 4. Slowly move the setting lever until it reads the same as the thermometer. 5. emove the cover. Hold the setting lever so it does not move, reinsert the wrench and carefully turn counterclockwise until the mercury rolls to the left end of the tube, but no farther. 6. echeck the calibration. Set the thermostat system switch for the desired operation and replace the cover. COIL SH ITHOUT CALIBATI ENCH M044A Fig. 9. ecalibration procedure. Automation and Control Solutions Honeywell 985 Douglas Drive North olden Valley, MN 554 Automation and Control Solutions Honeywell Limited-Honeywell Limitée 35 Dynamic Drive oad Scarborough, Ontario MV 4Z9 Printed in U.S.A. on recycled paper containing at least 0% 69-598.H. -0 post-consumer 6 paper fibers. www.honeywell.com/yourhome