Goodman Mfg AMV8 instruction manual GAS Input Rate Measurement Natural GAS only

gas piping drip leg. The supply pressure must be measured with the burners operating. To measure the gas supply pressure, use the following procedure.

With Power and Gas Off:

1.Connect a water manometer or adequate gauge to the “inlet pressure tap” of the gas valve.

As an alternative method, inlet gas pressure can also be measured by removing the cap from the drip leg and installing a predrilled cap with a hose fitting (Figure 26).

With Power and Gas On:

2.Put furnace into heating cycle and turn on all other gas consuming appliances.

If operating pressures differ from the Inlet Gas Supply Pressure table below, make necessary pressure regulator adjustments, check piping size, etc., and/or consult with local utility.

Gas Line

Gas

Shutoff

Valve

Gas Line

To Furnace

Open To

Atmosphere

Drip Leg Cap

With Fitting

Manometer Hose

Manometer

Measuring Inlet Gas Pressure (Alternate Method)

manifold pressure, use the following procedure.

1.Turn OFF gas to furnace at the manual gas shutoff valve external to the furnace.

2.Connect a calibrated water manometer (or appropriate gas pressure gauge) at the gas valve outlet pressure tap (refer to gas valve figure in previous section).

3.Turn ON the gas supply and operate the furnace.

4.Measure gas manifold pressure with burners firing. Adjust manifold pressure according to the table below:

		Manifold Gas Pressure
	Gas		Range		Nominal
Natural		Low Stage	1.6 - 2.2"	w.c.	1.9" w.c.
		High Stage	3.0 - 3.6"	w.c.	3.5" w.c.
Propane		Low Stage	5.7 - 6.3"	w.c.	6.0" w.c.
		High Stage	9.7 - 10.3" w.c.		10.0" w.c.

The final manifold pressure must not vary more than ± 0.3 “ w.c. from the above specified pressures. Any necessary major changes in gas flow rate should be made by changing the size of the burner orifice.

5.To adjust the gas valve pressure regulator, remove the regulator cap

6.Turn the adjustment screw clockwise to increase the pressure, or counterclockwise to decrease the pressure.

7.Securely replace the regulator cap.

8.Turn OFF gas to furnace at the manual shutoff valve and disconnect manometer.

9.Reinstall gas valve outlet pressure tap plug before turning on gas to furnace.

GAS INPUT RATE MEASUREMENT (NATURAL GAS ONLY)

3. Turn ON the gas supply and operate the furnace and all					The gas input rate to the furnace must never be greater than that
	other gas consuming appliances on the same gas supply
					specified on the unit rating plate. To measure natural gas input
	line.
					using the gas meter, use the following procedure.
4. Measure furnace gas supply pressure with burners firing.
						1. Turn OFF the gas supply to all other gas-burning appliances
	Supply pressure must be within the range specified in the
	table below.					except the furnace.
						2. While the furnace is operating, time and record one complete
		Inlet Gas Supply Pressure
						revolution of the smallest gas meter dial.
	Natural Gas	Minimum:	5.0" w.c.	Maximum:10.0" w.c.
						3. Calculate the number of seconds per cubic foot (sec/ ft3) of
	Propane Gas	Minimum: 11.0" w.c.		Maximum:13.0" w.c.
If supply pressure differs from table, make the necessary						gas being delivered to the furnace. If the dial is a one cubic
						foot dial, divide the number of seconds recorded in step 2
adjustments to pressure regulator, gas piping size, etc., and/or
						by one. If the dial is a two cubic foot dial, divide the number
consult with local gas utility.
						of seconds recorded in step 2 by two.
5. Turn OFF gas to furnace at the manual shutoff valve and						4. Calculate the furnace input in BTUs per hour (BTU/ hr). Input
	disconnect manometer.		Reinstall plug before turning on			equals the sum of the installation’s gas heating value and a
	gas to furnace.					conversion factor (hours to seconds) divided by the number
6. Turn OFF any unnecessary gas appliances stated in step						of seconds per cubic foot. The measured input must not be
3.						greater than the input indicated on the unit rating plate.
GAS MANIFOLD PRESSURE MEASUREMENT AND ADJUSTMENT						EXAMPLE:
						Installation’s gas heating (HTG) value: 1,000 BTU/ft3
			CAUTION			(Obtained from gas supplier)
						Installation’s seconds per cubic foot: 34 sec/ ft3
TO PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE, THE GAS						Conversion Factor (hours to seconds): 3600 sec/hr
MANIFOLD PRESSURE MUST BE AS SPECIFIED ON THE UNIT RATING PLATE.						Input = (Htg. value x 3600) ÷ seconds per cubic foot
ONLY MINOR ADJUSTMENTS SHOULD BE MADE BY ADJUSTING THE GAS VALVE
						Input = (1,000 BTU/ft3 x 3600 sec/hr) ÷ 34 sec/ ft3
PRESSURE REGULATOR.
Only small variations in gas pressure should be made by adjusting						Input = 106,000 BTU/hr
						This measured input must not be greater than the input
the gas valve pressure regulator. The manifold pressure must be
						indicated on the unit rating plate.
measured with the burners operating. To measure and adjust the
IO-247A				23		12/04