Bryant 355MAV instruction manual Redundant Automatic Gas Valve, Set Temperature Rise

INLET PRESSURE TAP

ON/OFF SWITCH

FFO

ON

LOW-FIRE ADJUSTMENT ALLEN SCREW (UNDER CAP)

HIGH-FIRE ADJUSTMENT ALLEN SCREW (UNDER CAP)

BURNER

ENCLOSURE

REFERENCE

PRESSURE TAP MANIFOLD

PRESSURE

TAP

A97386

Fig. 56—Redundant Automatic Gas Valve

BURNER

ORIFICE

A93059

Fig. 57—Burner Orifice

m.Move setup switch SW-2 to OFF position and jumper R and W2 thermostat connections. (See Fig. 31.) This keeps furnace locked in high-heat operation. Repeat items h through k for high-heat operation.

EXAMPLE: (High-heat operation at 0-2000 ft altitude) Furnace input from rating plate is 100,000 Btuh.

Btu heating input = Btu/cu ft X cu ft/hr Heating value of gas = 975 Btu/cu ft

Time for 1 revolution of 2-cu ft dial = 70 sec Gas rate = 103 cu ft/hr (from Table 15)

Btu heating input = 103 X 975 = 100,425 Btuh. In this example, the orifice size and manifold pressure adjustment is within ±2 percent of the furnace input rate.

NOTE: Measured gas inputs (high heat and low heat) must be within ±2 percent of that stated on furnace rating plate when installed at sea level or derated per that stated above when installed at higher altitudes.

n.Remove jumper across R, W/W1, and W2 thermostat connections to terminate call for heat.

B. Set Temperature Rise

CAUTION: Temperature rise must be within limits specified on unit rating plate. Recommended operation is at midpoint of rise or above. Failure to follow this caution may result in overheating the heat exchangers or condensing flue gases in heat exchanger areas not designed for condensate.

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