Bryant 581A/B manual Altitude COMPENSATION* 581B036-072, Altitude COMPENSATION* 581B090-150

PERFORMANCE DATA (cont)

FAN RPM AT MOTOR PULLEY SETTING WITH STANDARD MOTOR* — 581B036-150

UNIT						MOTOR PULLEY TURNS OPEN
581B	0	1/2	1	11/2	2		21/2	3	31/2	4	41/2	5	51/2	6
036	1044	1008	971	935	898		862	826	789	753	716	680	—	—
048	1185	1144	1102	1061	1019		978	936	895	853	812	770	—	—
060	1460	1425	1389	1354	1318		1283	1248	1212	1177	1141	1106	1070	1035
072	1585	1538	1492	1445	1399		1352	1305	1259	1212	1166	1119	—	—
090,102	1085	1060	1035	1010	985		960	935	910	890	865	840	—	—
120	1080	1060	1035	1015	990		970	950	925	905	880	860	—	—
150	1130	1112	1087	1062	1037		1212	987	962	937	912	887	962	830

*Approximate fan rpm shown (standard motor/drive).

FAN RPM AT MOTOR PULLEY SETTING WITH HIGH-STATIC MOTOR* — 581B036-150

UNIT						MOTOR PULLEY TURNS OPEN
581B	0	1/2	1	11/2	2		21/2	3	31/2	4	41/2	5	51/2	6
036	1455	1423	1392	1360	1328		1297	1265	1233	1202	1170	1138	1107	1075
048	1455	1423	1392	1360	1328		1297	1265	1233	1202	1170	1138	1107	1075
060	1685	1589	1557	1525	1493		1460	1428	1396	1364	1332	1300	—	—
072	1685	1589	1557	1525	1493		1460	1428	1396	1364	1332	1300	—	—
090	1080	1025	1007	988	970		952	933	915	897	878	860	—	—
102	1080	1025	1007	988	970		952	933	915	897	878	860	—	—
120	1130	1112	1087	1062	1037		1212	987	962	937	912	887	962	830

*Approximate fan rpm shown (high-static motor/drive).

581B036-150

ALTITUDE COMPENSATION* — 581B036-072

	72,000 AND 115,000/		150,000/120,000 BTUH
	60,000 and 90,000 BTUH
			NOMINAL INPUT
ELEVATION	NOMINAL INPUT
(ft)	Natural Gas	Liquid	Natural	Liquid
		Propane	Gas	Propane
	Orifice Size†
		Orifice Size†	Orifice Size	Orifice Size†
0-2,000	33/38	43	30/32	38
2,000	34/39	43	30/33	39
3,000	35/40	44	31/34	40
4,000	36/41	44	32/35	41
5,000	36/41	44	33/35	42
6,000	37/42	45	34/36	43
7,000	37/42	45	35/37	43
8,000	38/43	46	36/37	44
9,000	39/43	47	37/38	44
10,000	41/44	48	38/40	45
11,000	43/45	48	39/41	45
12,000	44/45	49	40/42	46
13,000	44/46	49	41/43	47
14,000	45/47	50	42/43	47

*As the height above sea level increases, there is less oxygen per cubic foot of air. Therefore, the input rate should be reduced at higher altitudes.

†Orifices are available through your local Bryant distributor.

ALTITUDE COMPENSATION* — 581B090-150

	125,000, 180,000, AND		250,000 BTUH
	224,000 BTUH
			NOMINAL INPUT
ELEVATION	NOMINAL INPUT
(ft)	Natural Gas	Liquid	Natural Gas	Liquid
	Orifice	Propane	Orifice	Propane
	Size†	Orifice Size†	Size†	Orifice Size†
0-2,000	31	41	30	38
2,000	32	42	30	39
3,000	32	42	31	40
4,000	32	42	32	41
5,000	33	43	33	42
6,000	34	43	34	43
7,000	35	44	35	43
8,000	36	44	36	44
9,000	37	45	37	44
10,000	38	46	38	45
11,000	39	47	39	45
12,000	40	47	40	46
13,000	41	48	41	47
14,000	42	48	42	47

*As the height above sea level increases, there is less oxygen per cubic foot of air. Therefore, the input rate should be reduced at higher altitudes.

†Orifices are available through your local Bryant distributor.

ALTITUDE DERATING FACTOR*

ELEVATION	MAXIMUM HEATING VALUE (Btu/ft3)
0-2000	1100
2001-3000	1050
3001-4000	1000
4001-5000	950
5001-6000	900

*Derating of the unit is not required unless the heating value of the gas exceeds the values listed in the table above, or if the elevation exceeds 6000 ft. Derating conditions must be 4% per thousand ft above 2000 ft. For example, at 4000 ft, if the heating value of the gas exceeds 1000 Btu/ ft3, the unit will require a 16% derating. For elevations above 6000 ft, the same formula applies. For example, at 7000 ft, the unit will require a 28% derating of the maximum heating value per the National Fuel Gas Code.

IMPORTANT: Local utility companies may be reducing heat content of gas at altitudes above 2000 ft. If this is being done, changing spuds may not be required.

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