Carrier 58PHA/PHX START-UP, ADJUSTMENT, and Safety Check, Fire and Explosion Hazard

58PHA

START-UP, ADJUSTMENT, AND SAFETY

CHECK

General

!WARNING

FIRE HAZARD

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

This furnace is equipped with manual reset limit switches in the gas control area. The switches open and shut off power to the gas valve if a flame rollout or overheating condition occurs in the gas control area. DO NOT bypass the switches. Correct inadequate combustion air supply problem before resetting the switches.

!CAUTION

CUT HAZARD

Failure to follow this caution may result in personal injury.

Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing furnaces.

1.Maintain 115-v wiring and ground. Improper polarity will result in rapid flashing LED and no furnace operation.

2.Make thermostat wire connections at the 24-v terminal block on the furnace control. Failure to make proper connections will result in improper operation. (See Fig. 25.)

3.Gas supply pressure to the furnace must be greater than 4.5-in. wc (0.16 psig ) but not exceed 14-in. wc (0.5 psig).

4.Check all manual-reset switches for continuity.

5.Install blower compartment door. Door must be in place to operate furnace.

6.Replace outer door.

Start-Up Procedures

!WARNING

FIRE AND EXPLOSION HAZARD

Failure to follow this warning could cause personal injury, death and/or property damage.

Never test for gas leaks with an open flame. Use a commercially available soap solution made specifically for the detection of leaks to check all connections.

1.Purge gas lines after all connections have been made.

2.Check gas lines for leaks.

3.To Begin Component Self-Test:

Remove blower access door. Disconnect the thermostat R lead from the furnace control board. Manually close the blower door switch closed. Short (jumper) the COM-24v terminal on control to the TEST/TWIN 3/16-inch quick connect terminal on control until LED goes out (approximately 2 sec). Gas valve and humidifier will not be turned on. (See Fig. 24.)

!WARNING

ELECTRICAL SHOCK HAZARD

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

Blower access door switch opens 115-v power to control. No component operation can occur unless switch is closed. Caution must be taken when manually closing this switch for service purposes.

NOTE: The furnace control allows all components, except the gas valve, to be run for short period of time. This feature helps diagnose a system problem in case of a component failure. Component test feature will not operate if any thermostat signal is present at the control.

Component test sequence is as follows:

Refer to service label attached to furnace or see Fig. 55.

a.LED will display previous status code 4 times.

b.Inducer motor starts and continues to run until Step f of component test sequence.

c.Hot surface igniter is energized for 15 sec., then off.

d.Blower motor operates on HEAT speed for 10 sec.

e.Blower motor operates on COOL speed for 10 sec.

f.Inducer motor stops.

g.Reconnect R lead to furnace control board, release blower door switch and re-install blower door.

4.Operate furnace per instruction on door.

5.Verify furnace shut down by lowering thermostat setting below room temperature.

6.Verify furnace restarts by raising thermostat setting above room temperature.

Adjustments

!WARNING

FIRE HAZARD

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

DO NOT bottom out gas valve regulator adjusting screw. This can result in unregulated manifold pressure and result in excess overfire and heat exchanger failures.

!CAUTION

FURNACE DAMAGE HAZARD

Failure to follow this caution may result in reduced furnace life.

DO NOT redrill orifices. Improper drilling (burrs, out-of-round holes, etc.) can cause excessive burner noise and misdirection of burner flames. This can result in flame impingement of heat exchangers, causing failures. (See Fig. 53.)

Furnace gas input rate on rating plate is for installations at altitudes up to 2000 ft. (610 M). Furnace input rate must be within +/-2 percent of furnace rating plate input. For altitudes above 5500 ft. (1676 M), a field-supplied high altitude pressure switch is required.

1.Determine the correct gas input rate.

In the U.S.A.:

36