External Relay Outputs
The control includes three outputs to drive external relays having 24 VAC coils. The outputs have a maximum rating of 1.0 Amp pilot duty at
24VAC.
HUM OUT
The HUM OUT output can be used to drive an external relay or solenoid (24 VAC coil) to control a humidifier. The output is energized when the HUM input is energized, the HUM STAT is in the YES position, and the control has a thermostat call for heating (heat pump or electric heat).
EAC
The EAC output can be used to drive an external relay (24 VAC coil) to control an electronic air cleaner. The output is energized whenever the blower relay on the control is energized. Models having a high effi- ciency non-variable speed motor use the EAC output as an input to the motor. The EAC output can also be used to drive an electronic air cleaner relay as long as the load of the EAC relay does not exceed 1.0 Amp. An additional connection to the EAC terminals must be made using a piggyback terminal or similar device.
LOW FAN
The LOW FAN output can be used to drive an external relay (24 VAC coil) that switches the power input to the motor to a lower speed tap. An accessory kit is available for this application.
The LOW FAN output is energized when the control has the following inputs.
TABLE 4: Low Fan Control Inputs
| Input | Operational Mode |
| | |
| G | Continuous Fan operation |
| Y1 or Y1 and O | First stage compressor operation |
| Y/Y2 and HUM de-energized with | Dehumidification during cooling |
| HUM STAT jumper in YES position |
| |
| | |
Blower Delays
The control includes the following blower delays:
TABLE 5: Blower Delays
Condition | Blower Delay |
| |
Following call for cooling | 60 seconds |
Following call for heat pump heating | 30 seconds |
Following call for electric heat heating | 10 seconds |
Heat Output and Limit Connections
The control is connected to the heater relays and limit switch using the 6-pin connector. The relay outputs and the limit switch signal are 24 VDC.
The control energizes the heat relays and senses the limit switch input as shown in Table 6 when the HEAT ENABLE jumper is in the HEAT position.
TABLE 6: Heat Relays
Input | Heat Relay Output |
| |
W1 | HT1 |
W2 | HT1 and HT2 |
W1 and W2 | HT1 and HT2 and HT3 |
The control energizes the first stage of electric heat immediately, the second stage 10 seconds after the call for second stage heat, and the third stage 20 seconds after the call for third stage heat.
Depending on the heat kit installed in the air handler, the control pro- vides the flexibility to configure the amount of heat delivered with the first stage heating call. As an example, when the control’s W1 input is connected to the room thermostat’s first stage heat signal, a call for first stage heat will energize one heating element (HT1). If the control’s W2 input is connected to the room thermostat’s first stage heat signal, a call for first stage heat will energize two heating elements (HT1 & HT2). With either configuration, the control will energize three heating ele- ments (HT1, HT2, & HT3) when it receives a first and second stage heat input from the thermostat.
Limit Switch and Lockout Operation
Limit Switch Operation
If the HEAT ENABLE jumper is in the HEAT position and the limit switch opens (fault code 1), the control will immediately de-energize all electric heat relay outputs and energize the blower (if it wasn’t already ener- gized). When the limit switch closes, the control will re-energize electric heat according to the thermostat inputs using normal timings.
Fan On Lock Condition
If the limit switch opens multiple times during a single call for electric heat (fault code 3) or if the limit switch opens for a long duration (fault code 4), the control will energize the blower until power is removed from the control. The control will cycle the heat outputs on and off as the limit re-closes and opens. The constant fan operation will signal the home- owner that a problem has occurred and a service call is required.
Soft Lockout
If the limit switch opens for a second long duration period during a sin- gle call for heat (fault code 5), the control will keep the blower locked on and lock out the heat outputs for one hour. The control will only reset this one hour lockout when the power is removed from the control. After the one hour period has passed, the control will re-energize electric heat according to the thermostat inputs using normal timings. The blower will remain locked on from the first long duration limit opening.
Hard Lockout
The control has a hard lockout condition during which the control will keep all heat outputs de-energized until power is removed from the con- trol. The control de-energizes the blower five minutes after entering the hard lockout condition.
If the limit switch closes and re-opens during the one hour soft lockout period, the control will enter a hard lockout condition and continue to indicate a fault code 5.
If the limit switch opens twice when no call for electric heat is present (fault code 2), the control will enter a hard lockout condition.
If the limit switch opens multiple times soon after a soft lockout reset (fault code 6), the control will enter a hard lockout condition.
Wiring Related Faults
If the control receives a simultaneous call for heating and cooling (fault code 7), the control will perform both heating and cooling operations.
SECTION VII: LINE POWER
CONNECTIONS
Power may be brought into the unit through the supply air end of the unit (top when unit is vertical) or the left side panel. Use the hole appro- priate to the unit’s orientation in each installation to bring conduit from the disconnect. The power lead conduit should be terminated at the electrical control box. To minimize air leakage, seal the wiring entry point at the outside of the unit. See Figure 3.
Refer to Tables to determine proper wire sizing: Tables 8 & 9 for cooling only or,
Tables 12 & 13 for single phase or, Tables 15 & 16 for three phase or, Table 18 for 460V.