Carrier 58MVP Installation, Start-up, And Operating Instructions Manual

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Carrier 58MVP Installation, Start-up, And Operating Instructions Manual Manual pdf 35 page image

a. Call for continuous fan—The thermostat closes R-Gcircuit.b. Blower on—The blower starts immediately.NOTE: The blower starts at approximately 400-500 RPM. After20 sec, the motor is turned off for 1/10 of a sec where a coast downcalibration is done to evaluate resistance of the conditioned airduct system. The microprocessor then determines blower RPMrequired to provide proper airflow for heating mode.NOTE: The continuous fan speed is the same as low-heat speedunless it is field adjusted to another desired airflow. See Continu-ous Fan Setup Switches section. There is also a chart on wiringdiagram. (See Fig. 24.)c. Electronic Air Cleaner—The EAC-1 terminal is ener-gized whenever blower operates, regardless of operatingmode.2. Operating with continuous fan (R-G) and call for heat(R-W/W1) is received—Same as heat pump mode exceptblower on delay is 10 sec less than heat mode. After call forheat (R-W/W1) is terminated, the blower remains operating atlow-heat speed for selected blower off delay before resumingcontinuous fan speed.3. Operating with continuous fan (R-G) and call for cooling(R-Y/Y2) is received—See Cooling Mode section. After callfor cooling (R-Y/Y2) is terminated, the blower remainsoperating at cooling speed for 90 sec before resuming con-tinuous fan speed.Step 8—Component TestAll components are functionally operated except gas valve withcomponent test feature.This feature helps diagnose a system problem in case of acomponent failure.NOTE: Setup switch SW-1 MUST be in OFF position or FaultCode 22 (setup error) will occur.NOTE: NO thermostat signal may be present at control center,and all blower time delay off periods must be completed.To initiate component test feature, proceed with the following:1. Leave 115-v power to furnace turned on.2. Remove main furnace door.3. Remove blower access panel.4. Move setup switch SW-6 to ON position.5. Manually close blower access panel door switch. Use a pieceof tape to hold switch closed.Blower access panel door switch opens 115-v power tocontrol center. No component operation can occur. Cautionmust be taken when manually closing this switch for servicepurposes. Failure to follow this warning could result inpersonal injury or death.When items 1-5 have been completed, the following will occur:1. The control center goes through a brief self-test. This self-testtakes approximately 2 sec to complete. After door switch isclosed, red (microprocessor) LED briefly comes on. Thengreen LED comes on for 1 sec, followed by 1 sec where bothgreen and yellow LEDs are on. During this time, the micro-processor is checking itself.2. Inducer motor operates for 20 sec at low speed, operates for 20sec at high speed, then turns off.3. Hot surface ignitor is energized for 15 sec, then de-energized.4. Main blower motor operates for 20 sec at low speed, operatesfor 20 sec at high speed, then turns off.5. After component operation test is completed, 1 or more faultcodes (11, 22, 41, or 42) will flash. See service label on backof main furnace door for explanation of fault codes.NOTE: To repeat component test, turn setup switch SW-6 to OFFand then back to ON.After component test, perform the following:1. Release blower panel access door switch and turn setup switchSW-6 to OFF position.2. If applicable, replace blower access panel and check LEDstatus by removing plug in blower access panel.3. Reinstall main furnace door if all LEDs are off, indicatingfurnace is ready to operate when a signal from thermostat isreceived.Step 9—Bypass Humidifier ModeWhen setup switch SW-3 BPH is in ON position, RPM calculatedfor low heat is multiplied by 1.15 for all furnace model sizes. Thiscompensates for increased return-air temperature caused by by-passed air supply.Step 10—Dehumidification ModeA dehumidification input is provided via a 1/4 in. male quick-connect terminal labeled DEHUM located next to the transformersecondary connections. The DEHUM input acts differently de-pending on which style of variable speed furnace control you have.The older style variable speed furnace control shown in Fig. 27,DOES NOT have a DE connection while the newer style variablespeed furnace shown in Fig. 27, has a DE connection. The newerstyle variable speed furnace control is expected to be available bymid 1998. Both of these variable speed furnace controls functionthe same except the DEHUM logic is reversed. This logic reversalhas come about from historical use of a standard humidistat to dodehumidification since the contacts open on high humidity, thusremoving the 24-v signal to initiate dehumidification.On the older style variable speed furnace controls a field suppliedrelay is required between the thermidistat or humidistat control andfurnace. The relay coil is connected between DHUM output on thethermidistat control and COM terminal on the furnace control or thehumidistat output and COM terminal on the furnace control. Itsnormally closed contact is connected between R and DEHUMterminals on the furnace control (see Fig. 27 and 28). When adehumidify demand exists, relay is de-energized and normallyclosed contacts supply 24-v to the furnace DEHUM terminal. Asa result, the furnace control reduces the blower airflow by 15percent to 340 CFM per ton during continuous fan or coolingoperation.On newer style variable speed furnace controls, a field suppliedrelay IS NOT required. The DEHUM output on the thermidistatcontrol or the humidistat output, is connected directly to theDEHUM terminal on the furnace control. In addition, the DEjumper located next to the DEHUM terminal must be removed toenable the DEHUM input (See Fig. 27 and 29). When a dehu-midify demand exists, the furnace control reduces the blowerairflow by 21 percent to 315 CFM per ton during continuous fanor cooling operation.This blower speed reduction compensates for high humidityconditions during cooling operation on all furnace model sizes.Reference Thermidistat™ Control Installation, Start-Up, and Op-erating Instructions for further details.Step 11—Zone ModeWhen setup switch SW-5 MZ is in ON position, blower motorcontrol is the same as above except with the following exceptions:35→