Humidity Switch Input; Required Control Set-Up; Fault Codes - York MA Installation Manual

262675-UIM-A-0806
NOTE: All wiring must comply with local and national electrical code
requirements. Read and heed all unit caution labels.
NOTE: It is possible to vary the amount of electric heat turned on during
the defrost cycle of a heat pump. Standard wiring will only bring on the
first stage of electric heat during defrost. See Heat Output and Limit
Connections and Table 6 for additional information on heat during
defrost cycle.
TABLE 2: Low Voltage Connections
Terminal Signal
R 24 VAC power (fused)
G Continuous Fan operation
Second or full stage
Y/Y2
compressor operation
First stage compressor
Y1
operation
W2 Second stage heat operation
W1 First stage heat operation
O Reversing valve operation
HUM

Humidity switch input

Connection point for
X/L
heat pump fault indicator
COM 24 VAC common
The low voltage connections may be connected to the screw terminals
or the quick connect terminals. The screw terminals and the quick con-
nect terminals are physically connected on the control board.
HUMIDITY SWITCH INPUT
The air handler control is designed to work with a humidity control that
closes when the humidity is below the set-point. The control is open
when the humidity is above the set-point. This humidity control may be
referred to as a humidistat or a dehumidistat.
The humidity switch controls both humidification and de-humidification
operation of the control. The control provides humidification using the
HUM OUT relay output and de-humidification by lowering the blower
speed. This is accomplished using the LOW FAN output and a field
installed two-speed fan relay kit for non-variable speed models and the
de-humidification input of the motor for variable speed models. The
humidity switch should be connected to the R and HUM terminals of the
control. See Figures 10 & 11.
SECTION VI: REQUIRED CONTROL
SET-UP
IMPORTANT: The following steps must be taken at the time of installa-
tion to insure proper system operation.
1. Consult system wiring diagram to determine proper thermostat
wiring for your system.
2. If heat kit is installed, change HEAT ENABLE jumper from NO
HEAT to HEAT position.
3. If a humidstat is installed, change HUM STAT jumper from NO to
YES.
4. Set the MODE jumper to A/C (Air Conditioner) or HP (Heat Pump)
position depending on the outdoor unit included with the system.
6
Comment
Not used with outdoor units
having one stage compressors.
24 VAC will be present at this
terminal when the MODE
jumper is in the AC position.
This is normal.
24 VAC will be present at this
terminal when the HUM STAT
jumper is in the NO position.
This is normal.
This terminal is a connection
point only and does not affect
air handler control operation.
FUNCTIONALITY AND OPERATION
Jumper Positions
Heat Enable Jumper
The HEAT ENABLE jumper configures the control for heat kit operation.
The jumper must be in the HEAT position if a heat kit is installed with
the air handler.
With the jumper in the NO HEAT position, the control will not energize
the heat relay outputs or sense the limit switch input.
If the jumper is not present, the control will operate as if the jumper is in
the HEAT position. If the jumper is not present and a heat kit is not
present, the control will sense an open limit condition and the blower
will run continuously.
Hum Stat Jumper
The HUM STAT jumper configures the control to monitor the humidity
switch input. With the jumper in the NO position, the control will ener-
gize the HUM terminal with 24 VAC continually. With the jumper in the
YES position, the control will monitor the HUM input to control the HUM
OUT output to control an external humidifier.
If the jumper is not present, the control will operate as if the jumper is in
the YES position.
Mode Jumper
The MODE jumper configures the control to operate properly with an air
conditioner (AC position) or heat pump (HP position). With the jumper in
the AC position, the control will energize the O terminal with 24 VAC
continually. With the jumper in the HP position, the O input signal is
received from the room thermostat.
If the jumper is not present, the control will operate as if the jumper is in
the HP position.
SPARE Jumper
The control includes a spare jumper that can be used if a jumper is lost.
The SPARE jumper does not have any effect on the operation of the
control.
Status and Fault Codes
The control includes an LED that displays status and fault codes. These
codes are shown in Table 3. The control will display the fault codes until
power is removed from the control or the fault condition is no longer
present.
TABLE 3: Fault Codes
Fault or Status Condition
Status
No power to control
Normal operation
Control in test mode
Control failure
Limit Faults
Limit switch currently open (not in lockout)
Multiple limit openings with no call for heat
Multiple limit openings during one call for heat
Single long duration limit opening
Multiple long duration limit openings
Fan failure
Wiring Related Faults
Simultaneous call for heating and cooling
Internal Control Faults
Control recovered from internal event
LED1 (RED)
Flash Code
OFF
2s ON / 2s OFF
Rapid Flash
ON
1
2
3
4
5
6
7
9
Unitary Products Group