Johnson Controls AV*(C) Series CONVENTIONAL LOW VOLTAGE CONTROL WIRING 24 VAC, UIM-D-1211

536636-UIM-D-1211

CONVENTIONAL LOW VOLTAGE CONTROL WIRING (24 VAC)

The 24 volt power supply is provided by an internally wired low voltage transformer which is standard on all models, However, if the unit is con- nected to a 208 volt power supply, the low voltage transformer must be rewired to the 208 volt tap. See the unit wiring label.

Field supplied low voltage wiring can exit the unit on the top right hand corner or the right hand side panel. Refer to Figure 3.

Remove desired knockout and pierce foil faced insulation to allow wir- ing to pass through. Use as small of a hole as possible to minimize air leakage.

Install a 7/8” plastic bushing in the selected hole and keep low voltage wiring as short as possible inside the control box.

To further minimize air leakage, seal the wiring entry point at the outside of the unit.

The field wiring is to be connected at the screw terminals of the control board. Refer to Figure 11 and 12.

NOTICE

.All wiring must comply with local and national electrical code require- ments. Read and heed all unit caution labels.

TABLE 2: Low Voltage Connections
Terminal	Signal	Comment
R	24 VAC power (fused)
G	Continuous Fan operation
Y/Y2	Second or full stage
	compressor operation
Y1	First stage compressor	Not used with outdoor units
	operation	having one stage compressors.
W2	Second stage heat operation
W1	First stage heat operation
		24 VAC will be present at this
O	Reversing valve operation	terminal when the MODE
		jumper is in the AC position.
		This is normal.
		24 VAC will be present at this
HUM	Humidity switch input	terminal when the HUM STAT
		jumper is in the NO position.
		This is normal.
	Connection point for	This terminal is a connection
X/L		point only and does not affect
	heat pump fault indicator
		air handler control operation.
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.

NOTICE

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 5 for additional information on heat during defrost cycle.

Air Handler Control Wiring

Air Handler Control Wiring

Typical A/C - Cooling only Applications

Typical A/C with Electric Heat Applications

THERMOSTAT

AIR HANDLER

1 - STAGE

THERMOSTAT

AIR HANDLER

1 - STAGE

BOARD

BOARD

R

R

AIR CONDITIONING

R

R

AIR CONDITIONING

G

G

G

G

Y

Y / Y2

Y

Y

Y / Y2

Y

W1

Y1

Y1

W2

W2

W2

W2

C

W1

HUMIDISTAT *

W1

W1

HUMIDISTAT *

O

C

O

HUM

HUM

X / L

X / L

COM

C

COM

C

FIGURE 12: Cooling Models with and without Electric Heat Wiring

* Optional dehumidification humidistat switch contacts open on humidity rise.

NOTES:

1.“Y/Y2” Terminal on air handler control board must be connected for full CFM and applications requiring 60 second blower off delay for SEER enhancement.

2.Remove humidistat jumper on air handler control board.

3.For heat pump applications - set MODE jumper on air handler control board to the HP position.

4.To change quantity of heat during HP defrost cycle - reverse connections at W1 and W2 on air handler control board.

8 Johnson Controls Unitary Products