Goodman Mfg CVC9/95, MVC95 Gasinputratemeasurementnaturalgasonly, Temperaturerise

STARTUP PROCEDURE & ADJUSTMENT

9.Close thermostat “R” and “W2” contacts to provide a call for high stage heat.

10.Remove regulator cover screw from the high (HI) outlet pressure regulator adjust tower and turn screw clockwise to increase pressure or counterclockwise to decrease pressure. Replace regulator cover screw.

11.Turn off all electrical power and gas supply to the system.

12.Remove the manometer hose from the hose barb fitting or outlet pressure boss.

13.Replace outlet pressure tap:

a.Honeywell VR9205 valve: Remove the 1/8" NPT hose barb fitting from the outlet pressure tap. Replace the outlet pressure boss plug and seal with a high quality thread sealer.

b.White-Rodgers 36G54 valve: Turn outlet pressure test screw in to seal pressure port (clockwise, 7 in-lb minimum).

14.Turn on electrical power and gas supply to the system.

15.Close thermostat contacts “R” and “W1/W2” to energize thevalve.

Using a leak detection solution or soap suds, check for leaks at outlet pressure boss plug (Honeywell valve) or screw (White-Rodg- ers valve). Bubbles forming indicate a leak. SHUTOFF GASAND REPAIRALL LEAKS IMMEDIATELY!

NOTE: For gas to gas conversion, consult your dealer for appropriate conversion.

	Manifold Gas Pressure
	Gas	Range		Nom inal
Natural	Low Stage	1.6 - 2.2"	w .c.	1.9" w .c.
	High Stage	3.2 - 3.8"	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.

GASINPUTRATEMEASUREMENT(NATURALGASONLY)

The gas input rate to the furnace must never be greater than that specified on the unit rating plate. To measure natural gas input using the gas meter, use the following procedure.

1.Turn OFF the gas supply to all other gas-burning appliances except the furnace.

2.While the furnace is operating, time and record one complete revolution of the smallest gas meter dial.

3.Calculate the number of seconds per cubic foot (sec/ft3) of gas being delivered to the furnace. If the dial is a one cubic foot dial, divide the number of seconds recorded in step 2 by one. If the dial is a two cubic foot dial, divide the number of seconds recorded in step 2 by two.

4.Calculate the furnace input in BTUs per hour (BTU/hr). Input equals the sum of the installation’s gas heating value and a conversion factor (hours to seconds) divided by the number of seconds per cubic foot. The measured input must not be greater than the input indicated on the unit rating plate.

EXAMPLE:

Installation’s gas heating (HTG) value: 1,000 BTU/ft3 (Obtained from gas supplier)

Installation’s seconds per cubic foot: 34 sec/ ft3

Conversion Factor (hours to seconds): 3600 sec/hr Input = (Htg. value x 3600) ÷ seconds per cubic foot Input = (1,000 BTU/ft3 x 3600 sec/hr) ÷ 34 sec/ ft3 Input = 106,000 BTU/hr

Minor changes to the input rate may be accomplished through manifold pressure adjustments at the gas valve. Refer to Startup Procedure and Adjustment - Gas Manifold Pressure Measurement and Adjustment section for details. NOTE: The final manifold pressure cannot vary by more than ± 0.3” w.c. from the specified setting. Consult your local gas supplier if additional input rate adjustment is required.

5.Repeat steps 2 through 4 on high stage.

6.Turn ON gas to and relight all other appliances turned off in step 1. Be certain that all appliances are functioning properly and that all pilot burners are operating.

TEMPERATURERISE

Temperature rise must be within the range specified on the unit rating plate.An incorrect temperature rise may result in condens- ing in or overheating of the heat exchanger. An airflow and tem- perature rise table is provided in the Specification Sheet applicable to your model. Determine and adjust temperature rise as follows:

1.Operate furnace with burners firing for approximately ten minutes. Ensure all registers are open and all duct dampers are in their final (fully or partially open) position.

2.Place thermometers in the return and supply ducts as close to the furnace as possible. Thermometers must not be influenced by radiant heat by being able to “see” the heat exchanger.

3.Subtract the return air temperature from the supply air temperature to determine the air temperature rise. Allow adequate time for thermometer readings to stabilize.

4.Adjust temperature rise by adjusting the circulator blower speed. Increase blower speed to reduce temperature rise. Decrease blower speed to increase temperature rise. Refer to Startup Procedure and Adjustment -Circulator Blower Speeds for speed changing details.

39