Bryant 355MAV instruction manual Sea Level

Table 13—Model 355MAV Orifice Size and Manifold Pressure for Correct Input

(Tabulated Data Based on 20,000 Btuh High Heat/13,000 Btuh Low Heat per Burner, Derated 2 Percent for Each 1000 ft Above

Sea Level)

ALTITUDE			AVG GAS						SPECIFIC GRAVITY OF NATURAL GAS
					0.58			0.60			0.62			0.64			0.66
	RANGE		HEAT VALUE
		(FT)	(BTU/CU FT)	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold
				no.		Pressure	no.		Pressure	no.		Pressure	no.		Pressure	no.		Pressure
			850	43		3.7/1.5	43		3.8/1.6	42		3.2/1.4	42		3.3/1.4	42		3.4/1.4
			875	43		3.5/1.5	43		3.6/1.5	43		3.7/1.6	43		3.8/1.6	42		3.2/1.4
Canada			900	44		3.7/1.6	43		3.4/1.4	43		3.5/1.5	43		3.6/1.5	43		3.7/1.6
			925	44		3.5/1.5	44		3.7/1.6	44		3.8/1.6	43		3.4/1.4	43		3.5/1.5
		0	950	44		3.4/1.4	44		3.5/1.5	44		3.6/1.5	44		3.7/1.6	44		3.8/1.6
and		to	975	44		3.2/1.3	44		3.3/1.4	44		3.4/1.4	44		3.5/1.5	44		3.6/1.5
		2000	1000	45		3.7/1.6	45		3.8/1.6	44		3.2/1.4	44		3.4/1.4	44		3.5/1.5
U.S.A.
			1025	45		3.5/1.5	45		3.6/1.5	45		3.7/1.6	44		3.2/1.3	44		3.3/1.4
			1050	45		3.3/1.4	45		3.4/1.5	45		3.6/1.5	45		3.7/1.6	45		3.8/1.6
			1075	45		3.2/1.3	45		3.3/1.4	45		3.4/1.4	45		3.5/1.5	45		3.6/1.5
			1100	47		3.6/1.5	47		3.7/1.6	45		3.2/1.4	45		3.4/1.4	45		3.5/1.5
ALTITUDE			AVG GAS						SPECIFIC GRAVITY OF NATURAL GAS
					0.58			0.60			0.62			0.64			0.66
	RANGE		HEAT VALUE
		(FT)	(BTU/CU FT)	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold
				no.		Pressure	no.		Pressure	no.		Pressure	no.		Pressure	no.		Pressure
			775	43		3.8/1.6	42		3.2/1.4	42		3.3/1.4	42		3.4/1.4	42		3.5/1.5
		Altitudes	800	43		3.5/1.5	43		3.7/1.5	43		3.8/1.6	42		3.2/1.4	42		3.3/1.4
			825	44		3.8/1.6	43		3.4/1.5	43		3.6/1.5	43		3.7/1.5	43		3.8/1.6
Canada		2001
		to	850	44		3.6/1.5	44		3.7/1.6	44		3.8/1.6	43		3.5/1.5	43		3.6/1.5
		3000	875	44		3.4/1.4	44		3.5/1.5	44		3.6/1.5	44		3.7/1.6	43		3.4/1.4
and		or
			900	44		3.2/1.4	44		3.3/1.4	44		3.4/1.4	44		3.5/1.5	44		3.6/1.5
		Canada
			925	45		3.7/1.5	45		3.8/1.6	44		3.2/1.4	44		3.3/1.4	44		3.4/1.5
U.S.A.		Altitudes
		2000	950	45		3.5/1.5	45		3.6/1.5	45		3.7/1.6	45		3.8/1.6	44		3.3/1.4
		to	975	45		3.3/1.4	45		3.4/1.4	45		3.5/1.5	45		3.6/1.5	45		3.8/1.6
		4500
			1000	47		3.7/1.6	45		3.2/1.4	45		3.4/1.4	45		3.5/1.5	45		3.6/1.5
			1025	47		3.6/1.5	47		3.7/1.6	45		3.2/1.3	45		3.3/1.4	45		3.4/1.4
ALTITUDE			AVG GAS						SPECIFIC GRAVITY OF NATURAL GAS
					0.58			0.60			0.62			0.64			0.66
	RANGE		HEAT VALUE
		(FT)	(BTU/CU FT)	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold	Orifice		Manifold
				no.		Pressure	no.		Pressure	no.		Pressure	no.		Pressure	no.		Pressure
			750	43		3.7/1.6	43		3.8/1.6	42		3.3/1.4	42		3.4/1.4	42		3.5/1.5
			775	43		3.5/1.5	43		3.6/1.5	43		3.7/1.6	43		3.8/1.6	42		3.2/1.4
			800	44		3.7/1.6	43		3.4/1.4	43		3.5/1.5	43		3.6/1.5	43		3.7/1.6
Only			825	44		3.5/1.5	44		3.6/1.5	44		3.8/1.6	43		3.4/1.4	43		3.5/1.5
		3001	850	44		3.3/1.4	44		3.4/1.4	44		3.5/1.5	44		3.7/1.5	44		3.8/1.6
U.S.A.		to	875	45		3.8/1.6	44		3.2/1.4	44		3.3/1.4	44		3.5/1.5	44		3.6/1.5
		4000	900	45		3.6/1.5	45		3.7/1.6	45		3.8/1.6	44		3.3/1.4	44		3.4/1.4
			925	45		3.4/1.4	45		3.5/1.5	45		3.6/1.5	45		3.7/1.6	44		3.2/1.3
			950	45		3.2/1.4	45		3.3/1.4	45		3.4/1.5	45		3.5/1.5	45		3.7/1.5
			975	47		3.6/1.5	45		3.2/1.3	45		3.3/1.4	45		3.4/1.4	45		3.5/1.5
			1000	47		3.5/1.5	47		3.6/1.5	45		3.7/1.6	45		3.2/1.4	45		3.3/1.4

* Orifice numbers 45 are factory installed.

NOTE: DO NOT set low-heat manifold pressure less than 1.3-in. wc or more than 1.7-in. wc for natural gas. If manifold pressure is outside this range, change main burner orifices.

CAUTION: 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.

NOTE: If orifice hole appears damaged or it is suspected to have been redrilled, check orifice hole with a numbered drill bit of correct size. Never redrill an orifice. A burr-free and squarely aligned orifice hole is essential for proper flame characteristics.

f.Move setup switch SW-2 to OFF position after completing low-heat adjustment.

g.Jumper R and W2 thermostat connections on control center. (See Fig. 31.) This keeps furnace locked in high-heat operation.

h.Turn high-heat adjusting screw (5/64 hex Allen wrench) counterclockwise (out) to decrease input rate or clockwise (in) to increase rate.

NOTE: DO NOT set high-heat manifold pressure less than 3.2-in. wc or more than 3.8-in. wc for natural gas. If manifold pressure is outside this range, change main burner orifices.

i.When correct input is obtained, replace caps that conceal gas valve regulator adjustment screws. Main burner flame should be clear blue, almost transparent. (See Fig. 58.)

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