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819288-UIM-A-0212
Unitary Products Group 15
* Optional dehumidification humidistat switch contacts open on humidity rise.
Notes:
1. “Y” Terminal on Air Handler Control Board must be connected for full CFM and applications requiring 60 second blower off delay for SEER enhancement.
2. Move HUM STAT Jumper on AH Control Board to YES position if Humidistat is used.
3. MODE Jumper on AH control board should be set to A/C for air conditioners.
* Optional dehumidification humidistat switch contacts open on rise.
Notes:
1. “Y” Terminal on Air Handler Control Board must be connected for full CFM and applications requiring 60 second blower off delay for SEER enhancement.
2. Move HUM STAT Jumper on AH Control Board to YES position if Humidistat is used.
3. MODE Jumper on AH control board should be set to HP for heat pumps.
4. To change quantity of heat during HP defrost cycle - Reverse connections at W1 & W2 on Air Handler Control Board.
SECTION X: MAINTENANCE
Filters must be cleaned or replaced when they become dirty. Inspect at
least once per month. The frequency of cleaning depends upon the
hours of operation and the local atmospheric conditions. Clean filters
keep unit efficiency high.
LUBRICATION
The bearings of the blower motor are permanently lubricated.
FIGURE 11: Cooling Models with Electric Heat Wiring
MA SERIES - Air Handler Control Wiring
Typical A/C - Cooling only Applications
THERMOSTAT
AIR HANDLER
BOARD
1-STAGE
AIR CONDITIONING
RR
G
Y
W1
W2
C
G
W1
W2
Y
C
Y/Y2
Y1
O
HUM
X/L
COM
HUMIDISTAT
*
THERMOSTAT
AIR HANDLER
BOARD
1-STAGE
AIR CONDITIONING
RR
G
Y
W1
W2
C
G
W1
W2
Y
C
Y/Y2
Y1
O
HUM
X/L
COM
HUMIDISTAT
*
MA SERIES - Air Handler Control Wiring
Typical A/C with Electric Heat Applications
FIGURE 12: Single-Stage Cooling Wiring
THERMOSTAT
AIR HANDLER
BOARD
HEAT PUMP
R
R
R
G
G
Y
W/W1
O
W
O
O
C
X/L
X/L
C
Y/Y2
Y1
Y
W1 66
W2
W1
HUM
COM
HUMIDISTAT
*
W2
E
X/L
And Newer UPG Single Stage HP Systems
CONTROL WIRING - AHP or MA Series Air Handler
Single Stage H/P with Standard Demand Defrost Control Board