Trane DD1C100A9H51B, UD1D120A9H51B Control And Safety Switch Adjustment, Operating Information

CONTROL AND SAFETY SWITCH

ADJUSTMENT

LIMIT SWITCH CHECK OUT

The limit switch is a safety device designed to close the gas valve should the furnace become overheated. Since proper operation of this switch is important to the safety of the unit, it must be checked out on initial

start up by the installer.

To check for proper operation of the limit switches, set the thermostat to a temperature higher than the indi- cated temperature to bring on the gas valve. Restrict the airflow by blocking the return air or by disconnect- ing the blower. When the furnace reaches the maxi- mum outlet temperature as shown on the rating plate, the burners must shut off. If they do not shut off after a reasonable time and overheating is evident, a faulty limit switch is probable and the limit switch must be re- placed. After checking the operation of the limit control, be sure to remove the paper or cardboard from the re- turn air inlet, or reconnect the blower.

AIRFLOW ADJUSTMENT

Check inlet and outlet air temperatures to make sure they are within the ranges specified on the furnace rat- ing nameplate. If the airflow needs to be increased or decreased, see the wiring diagram for information on changing the speed of the blower motor.

▲! WARNING

Disconnect power to the unit before removing the blower door.

Failure to follow this warning could result in property damage, personal injury or death.

This unit is equipped with a blower door switch which cuts power to the blower and gas valve causing shut- down when the door is removed. Operation with the door removed or ajar can permit the escape of danger- ous fumes. All panels must be securely closed at all times for safe operation of the furnace.

NOTE:

Direct drive motors have bearings which are perma- nently lubricated and under normal use, lubrication is not recommended.

INDOOR BLOWER TIMING

The control module controls the indoor blower. The blower starts approximately 45 seconds after ignition. The FAN-OFF period is approximately 100 seconds from the interruption of gas flow.

ROOM AIR THERMOSTAT HEAT ANTICIPATOR ADJUSTMENT

Set the thermostat heat anticipator according to the current flow measured, or the settings found in the notes on the furnace wiring diagram (found inside the furnace casing).

Installer’s Guide

INSTRUCTIONS TO THE OWNERS

In the event that electrical, fuel, or mechanical failures occur, the owner should immediately turn the gas supply off at the manual gas valve, located in the burner compartment (See Figure 24). Also turn off electrical power to the furnace and contact the service agency designated by your dealer.

▲! WARNING

Should overheating occur, or the gas supply fail to shut off, shut off the gas valve to the unit before shut- ting off the electrical supply.

Failure to follow this warning could result in property damage, personal injury or death.

The following warning complies with State of California law, Proposition 65.

▲! WARNING

This product contains fiberglass wool insulation!

Fiberglass dust and ceramic fibers are believed by the State of California to cause cancer through inhalation. Glasswool fibers may also cause respiratory, skin, or eye irritation.

PRECAUTIONARY MEASURES

●Avoid breathing fiberglass dust.

●Use a NIOSH approved dust/ mist respirator.

●Avoid contact with the skin or eyes. Wear long- sleeved, loose-fitting clothing, gloves, and eye protection.

●Wash clothes separately from other clothing: rinse washer thoroughly.

●Operations such as sawing, blowing, tear-out, and spraying may generate fiber concentrations requiring additional respiratory protection. Use the appropriate NIOSH approved respirator in these situations.

FIRST AID MEASURES

Eye Contact – Flush eyes with water to remove dust. If symptoms persist, seek medical attention.

Skin Contact – Wash affected areas gently with soap and warm water after handling.

OPERATING INFORMATION

FLAME ROLL-OUT DEVICE

All models are equipped with a thermal control device on the burner cover. In case of flame roll-out, the device will cause the circuit to open which shuts off all flow of gas.

ABNORMAL CONDITIONS

1.EXCESSIVE COMBUSTION VENT PRESSURE OR FLUE BLOCKAGE

If pressure against the induced draft blower outlet becomes excessive, the pressure switch will shut off the gas valve until acceptable combustion pressure is again available.

18-CD21D1-5 23