Comfort-Aire WDG Air Handler Series - Manual (Page 20)

20
Installation, Operation & Maintenance WDG AIR HANDLER SERIES Heat Controller, LLC
Figure 15: Power Wiring, Dual Circuits, 15 and 20kw
Wiring and Setup (all models)
1. Install power wiring and connect to power block or circuit
breakers. In 12, 15 or 20kW models two power circuits may
be used to reduce wiring and breaker costs as in Figure 16.
If a single circuit supply is desired, install the optional single
circuit accessory kit (P/N 16B0002N02), as shown in Figure
15, that can be obtained from your distributor.
2. Ensure unit airfl ow setting is above minimum airfl ow rating for
the electric heat model from Table 2.
3. Check staging jumpers for the application. Typically only
5 kW (factory setting on all models except 10kW on 20kW
models) is needed for fi rst stage electric (W1) to minimize
electric demand. This staging can be adjusted by moving the
staging jumpers as shown in Figure 17. Whatever is jumped
to P1 pin 1 will be energized on 1st stage of electric heat,
and P1-2 will be energized as stage 2 electric heat. See
Table 5 for staging options.
4. Mark the appropriate box of the electric heat model installed
on the additional serial plate on the exterior of the unit.
5. Turn on the power to the unit and the auxiliary
electric heat.
Auxiliary Electric Heat Start-up
Put thermostat in emergency heat mode (or jumper thermostat
input R to W and R to G) and set point to high setting. Unit will
require 15-20 seconds before engaging emergency heat mode
stage 1 (W1) and then another 15-20 seconds to engage stage 2
(W2) when in ‘Test mode’. Verify proper electric heat operation.
Figure 16: Staging Jumpers
Figure 13: Power Wiring, 4, 5, 8, and 10kw
Electric Heat Wiring
21 2))
21 2))
   
3
,QDQGN:XQLWV
WZRSRZHUFLUFXLWVDUH
HPSOR\HGWRUHGXFHZLUHV
VL]HDQGFRVWRIEUHDNHUV
/
/
/
/
3
&RQGXLW
NO
Com
ER1
NO
Com
ER2
NO
Com
ER3
NO
Com
ER4
1 2 3
Tan
Ora
Factory Staging
(see Table 2)
Low Voltage Connector
(from Unit Control Board)
AG Electric Heat
Relay Board
P1 P2
24V
W1
W2
4
5kW (‘ER1’ 5kW & ‘ER4’ 0kW) and W2 (second stage)
will have 10kW (‘ER2 & 3’ 5kW each)
1 2 3 4
Tan
Ora
P2
Side View as seen in Control Box
P1
Staging Example on a 15kW unit W1 (first stage) has
blank
HG
Figure 14: Power Wiring, Single Circuit, 15, 20kw