Bryant 355MAV Procedure 3-PRIME Condensate Trap with Water, Procedure 4-PURGE GAS Lines

2.Locate setup switches on control center. (See Fig. 31.)

3.See Table 11 for setup switch description. (See Fig. 30.)

4.Replace main furnace door and blower access panel.

Table 11—Setup Switch Description

SETUP	NORMAL	DESCRIPTION
SWITCH NO.	POSITION	OF USE
SW-1	OFF	Turn switch to ON for fault history display. No thermostat signal
(FLT)		can be present for fault history display.
SW-2		Turn switch to ON to lock furnace in low-heat mode only or
	OFF	when using a 2-stage thermostat with a R-W/W1 and R-W2 sig-
(LOW)
		nals.
SW-3		Turn switch to ON when a bypass humidifier is used. This com-
	OFF	pensates for higher return-air temperature and provides 15 per-
(BPH)
		cent more airflow in low-heat mode only.
SW-4		Turn switch to ON to bypass microprocessor control. Furnace
	OFF	will operate at high heat only with main blower and inducer mo-
(EMER HEAT)
		tor operating at maximum RPM. NO safeties are bypassed.
SW-5		Turn switch to ON when modulating dampers are used. In this
	OFF	mode, main blower speed is recalculated once every minute
(MZ)
		while furnace is in low-heat or continuous fan mode.
		Turn switch to ON to initiate component test. Furnace will oper-
SW-6		ate inducer motor for 20 sec at low speed, operate inducer motor
	OFF	for 20 sec at high speed, energize HSI for 15 sec, operate blower
(COMP TEST)		for 20 sec at low speed, and operate blower for 20 sec at high
		speed. SW-1 must be in OFF position. No thermostat signal can
		be present for component test to be initiated.
SW-7 and SW-8	See Table 12	Adjust switches to provide desired heating mode blower off de-
(Blower Off Delay)		lay time. 90, 135, 180, or 225 sec.

Table 12—Blower Off Delay Setup Switch Position

DESIRED HEATING	SETUP SWITCH (SW-7 AND SW-8) POSITION
MODE BLOWER
	SW-7	SW-8
OFF DELAY (SEC)
90	OFF	OFF
135	ON	OFF
180	OFF	ON
225	ON	ON

NOTE: If a bypass humidifier is used, setup switch SW-3 (BPH) should be in ON position. This prevents nuisance limit trips caused by the increased temperature in return air resulting from bypass.

NOTE: If modulating dampers are used, setup switch SW-5 (MZ) should be in ON position. This allows furnace control center to compensate for modulating dampers. The control re-calibrates for new system static conditions once every minute while operating in low-heat or continuous fan modes.

PROCEDURE 3—PRIME CONDENSATE TRAP WITH WATER

CAUTION: Condensate trap must be PRIMED or proper draining may not occur. The condensate trap has 2 internal chambers which can ONLY be primed by pouring water into the inducer drain side of condensate trap.

1.Remove upper inducer housing drain connection cap. (See Fig. 54.)

2.Connect field-supplied 1/2-in. ID tube to upper inducer housing drain connection.

3.Insert field-supplied funnel into tube.

4.Pour 1 quart of water into funnel/tube. Water should run through inducer housing, overfill condensate trap, and flow into open field drain. (See Fig. 55.)

5.Remove funnel and tube from inducer housing and replace drain connection cap and clamp.

PROCEDURE 4—PURGE GAS LINES

If not previously done, purge the lines after all connections have been made and check for leaks.

WARNING: Never purge a gas line into a combustion chamber. Never use matches, candles, flame, or other sources of ignition for the purpose of checking leakage. Use a soap-and-water solution to check for leakage. Failure to follow this warning could result in fire, explosion, personal injury, or death.

PROCEDURE 5—ADJUSTMENTS

A. Set Gas Input Rate

Furnace gas input rate on rating plate is for installations at altitudes up to 2000 ft.

In the U.S.A., the input rating for altitudes above 2000 ft must be reduced by 2 percent for each 1000 ft above sea level. In Canada, the input rating must be derated by 5 percent for altitudes of 2000 ft to 4500 ft above sea level.

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