Bryant 588A, 589A user manual Rated Gas Inputs at Indicated Manifold Pressures, Orifices

Table 5 Ð Rated Gas Inputs at Indicated Manifold Pressures

		GAS SUPPLY PRESSURE				MANIFOLD		NATURAL GAS		PROPANE*
	NUMBER		(in. wg)
						PRESSURE
UNIT 588A, 589A	OF	Natural		Propane		(in. wg)		Ori®ce	Heating	Ori®ce	Heating
	ORIFICES							Drill	Input	Drill	Input
		Min	Max	Min	Max	Natural	Propane	Size	(Btuh)²	Size	(Btuh)²
018040, 024040, 030040	1	4.0	13.0	4.0	13.0	3.5	3.1	32	40,000	41	40,000
024060, 030060, 036060, 042060	2	4.0	13.0	4.0	13.0	3.5	3.3	40	56,000	47	54,000
030080, 036080, 042080,	2	4.0	13.0	4.0	13.0	3.5	3.4	32	80,000	42	80,000
048080, 060080
036100, 042100, 048100, 060100	2	4.0	13.0	4.0	13.0	3.5	3.7	30	95,000	40	95,000
036120, 042120, 048120, 060120	3	4.0	13.0	4.0	13.0	3.5	3.5	32	120,000	42	115,000
048140, 060140	3	4.0	13.0	4.0	13.0	3.5	3.4	31	136,000	40	133,000

* When a unit is converted to propane, different size ori®ces must be used. See separate natural-to-propane conversion kit instructions.

²Based on altitudes from sea level to 2000 ft above sea level. For altitudes above 2000 ft: reduce input rating 4% for each additional 1000 ft above 2000 ft. In Canada, from 2000 ft above sea level to 4500 ft above sea level, derate the unit 10%.

NOTE: Unit size 018 is 588A only.

Measure Gas Flow (Natural Gas Units)

Minor adjustment to the gas ¯ow can be made by changing the manifold pressure. The manifold pressure must be main- tained between 3.4 and 3.6 in. wg. If larger adjustments are required, change main burner ori®ces following the recom- mendations of national and local codes.

NOTE: All other appliances that use the same meter must be turned off when gas ¯ow is measured at the meter.

Proceed as follows:

1.Turn off gas supply to unit.

2.Remove pipe plug on manifold (see Fig. 24), then con- nect manometer at this point. Turn on gas to unit.

3.Record number of seconds for gas meter test dial to make one revolution.

4.Divide number of seconds in Step 3 into 3600 (number of seconds in one hour).

5.Multiply result of Step 4 by the number of cu ft shown for one revolution of test dial to obtain cu ft of gas ¯ow per hour.

6.Multiply result of Step 5 by Btu heating value of gas to obtain total measured input in Btuh. Compare this value with heating input shown in Table 5. (Consult the local gas supplier if the heating value of gas is not known.)

EXAMPLE: Assume that the size of test dial is 1 cu ft, one revolution takes 30 seconds, and the heating value of the gas is 1050 Btu/ft3. Proceed as follows:

1.30 seconds to complete one revolution.

2.3600 ÷ 30 = 120.

3.120 x 1 = 120 ft3 of gas ¯ow/hr.

4.120 x 1050 = 126,000 Btuh input.

If the desired gas input is 120,000 Btuh, only a minor change in the manifold pressure is required.

Observe manifold pressure and proceed as follows to ad- just gas input:

1.Remove cover screw over regulator adjustment screw on gas valve.

2.Turn regulator adjustment screw clockwise to increase gas input, or turn regulator adjustment screw counter- clockwise to decrease input. Manifold pressure must be between 3.4 and 3.6 in. wg.

MANIFOLD PIPE PLUG

Fig. 24 Ð Burner Assembly

WARNING: Unsafe operation of the unit may result if manifold pressure is outside this range. Personal in- jury or unit damage may result.

3.Replace cover screw cap on gas valve.

4.Turn off gas supply to unit. Remove manometer from pressure tap and replace pipe plug on gas valve. Turn on gas to unit and check for leaks.

Ð24Ð