Goodman Mfg AMV8 blinks once for each 100 CFM of airflow, Temperature Rise Measurement

5.Turn ON gas and relight appliances turned off in step 1. Ensure all the appliances are functioning properly and that all pilot burners are operating.

TEMPERATURE RISE

Air temperature rise is the temperature difference between supply and return air. The proper amount of temperature rise is usually obtained when the unit is operated at the rated input with the “as shipped” blower speed. If the correct amount of temperature rise is not obtained, it may be necessary to change the blower speed.

An incorrect temperature rise can cause condensing in or overheating of the heat exchanger. Determine and adjust the temperature rise as follows. The temperature rise must be within the range specified on the rating plate or Product Data Book applicable to your model*.

HEAT EXCHANGER

RADIATION "LINE OF SIGHT"

SUPPLY

AIR

TSU PPLY

RISE = TSU PPLY - TRET URN

TRET URN

RETURN

AIR

Temperature Rise Measurement

1.Operate furnace with burners firing approximately 15 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 the following section for speed changing details.

CIRCULATOR BLOWER SPEED ADJUSTMENT

WARNING

TO AVOID PERSONAL INJURY OR DEATH DUE TO ELECTRICAL SHOCK, TURN OFF POWER TO THE FURNACE BEFORE CHANGING SPEED TAPS.

All furnaces are shipped with heating speed set at “B” and cooling speed set at “D”. Use the following procedure to select the heating and cooling speed needed for your unit.

Use the CFM LED (green), adjacent to the integrated control module fuse to verify airflow quantity. The green CFM LED

blinks once for each 100 CFM of airflow.

1.Determine the tonnage of the cooling system installed with the furnace. If the cooling capacity is in BTU/hr divide it by 12,000 to convert capacity to TONs.

Example: Cooling Capacity of 30,000 BTU/hr. 30,000/12,000 = 2.5 Tons

2.Determine the proper air flow for the cooling system. Most cooling systems are designed to work with air flows between 350 and 450 CFM per ton. Most manufacturers recommend an air flow of about 400 CFM per ton.

Example: 2.5 tons X 400 CFM per ton = 1000 CFM

The cooling system manufacturer’s instructions must be checked for required air flow. Any electronic air cleaners or other devices may require specific air flows, consult installation instructions of those devices for requirements.

3.Knowing the furnace model, locate the high stage cooling air flow charts in the Product Data Book applicable to your model* . Look up the cooling air flow determined in step 2 and find the required cooling speed and adjustment setting. Example: A 70 kBtu furnace is to be installed with a 2.5

ton air conditioning system. The air flow needed is 1000 CFM. Using the cooling speed chart for the 70 kBtu furnace, find the airflow closest to 1000 CFM. A cooling airflow of 990 CFM can be attained by setting the cooling speed to “C” and the adjustment to “-” (minus). NOTE: Continuous Fan Speed will be 56% of high stage cooling.

4.Locate the blower speed selection DIP switches on the integrated control module. Select the desired “cooling” speed tap by positioning switches 1 and 2 appropriately. Select the desired “adjust” tap by positioning switches 3 and 4 appropriately. Refer to the following figure for switch positions and their corresponding taps. Turn off power to furnace for a minimum of 10 seconds, allowing motor to reset and recognize new speed selection. Turn on power to furnace. Verify CFM by counting the number of times the green CFM LED blinks.

5.The multi-speed circulator blower also offers several custom ON/OFF ramping profiles. These ramping profiles may be used to enhance cooling performance and increase comfort level. The ramping profiles are selected using DIP switches 5 and 6. Refer to the following figure for switch positions and their corresponding taps. Refer to the bullet points below for a description of each ramping profile. Turn off power to furnace for a minimum of 10 seconds, allowing motor to reset and recognize the new profile selection. Turn on power to the furnace. Verify profile selection by counting the green CFM LED blinks and timing each step of the ramping profile

•Profile A provides only an OFF delay of 1 minute at 100% of the cooling demand airflow.

100% CFM	100% CFM
OFF	OFF
Cooling	1 min
Demand

•Profile B ramps up to full cooling demand airflow by first stepping up to 50% of the full demand for 30 seconds. The motor then ramps to 100% of the required airflow. A 1 minute OFF delay at 100% of the cooling airflow.

IO-247A 24 12/04