GMVC9 GCVC9 Installation Instructions

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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 Specification Sheet 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 *MVC960603B* furnace installed with a 2.5
ton air conditioning system. The air flow
needed is 1000 CFM. Looking at the cooling
speed chart for *MVC960603B*, find the air
flow closest to 1000 CFM. A cooling airflow of
1007 CFM can be attained by setting the
cooling speed to “C”.
5. Locate the blower speed selection DIP (S3) 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. To enable adjustments and select -
5, 5, -10 or 10% trim, you must set dip switch S5-2 to
OFF
100% CFM 100% CFM
1 min
OFF
Figure 50
• provides only an OFF delay of one (1) minute at 100% of the cooling demand airflow. Profile A
50% CFM
1/2 min
100% CFM
100% CFM
1 min
OFF
OFF
Figure 51
• 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 one (1)
minute OFF delay at 100% of the cooling airflow is provided.
Profile B
100% CFM
OFF
OFF
• ramps up to 85% of the full cooling demand airflow and operates there for
approximately 7 1/2 minutes. The motor then steps up to the full demand airflow. Profile C
also has a one (1) minute 100% OFF delay.
Profile C
Figure 52
ON. If S5-2 is in the OFF position , you will receive 0%
trim. Refer to the following figure for switch positions
and their corresponding taps. Verify CFM by noting the
number displayed on the dual 7-segment LED display.
6. The multi-speed circulator blower also offers several
custom ON/OFF ramping profiles. These profiles may be
used to enhance cooling performance and increase comfort
level. The ramping profiles are selected using DIP
switches S4- 1, 2. Refer to the following figure for switch
positions and their corresponding taps. Refer to the
following bullet points for a description of each ramping
profile. Verify CFM by noting the number displayed on
the dual 7-segment LED display.
12
A* OFF OFF
BONOFF
COFFON
DONON
Switch Bank: S4
DIP Sw itch No.
(*Indicates factory setting)
Ramping
Profiles