669997-UAI-H-0514
Johnson Controls Unitary Products
5
ELECTRIC HEATERS & OPERATING
CONTROLS
LOW VOLTAGE CONTROL CONNECTIONS
The low voltage transformer and the fan control are standard on
all models.
The 24 volt power supply is provided by an internally wired low
voltage transformer which is standard on all air handler models.
Field supplied low voltage wiring can exit the unit on the top
right hand corner or the right hand side panel. Refer to Figure 1.
Remove desired knockout and pierce foil faced insulation to
allow wiring to pass through. Use as smallest hole 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.
For blower speed connections, electrical information and wir-
ing diagrams, see indoor unit installation instructions.
The electric heaters have both auto resettable and one shot
thermal limit controls.
If failure occurs, this one shot thermal limit control must be
replaced with a direct replacement.
NOTICE
NOTICE
All wiring must comply with local and national electrical code
requirements. Read and heed all unit caution labels.
NOTICE
FIGURE 4:
Typical Installed Application
UPFLOW
HORIZONTAL RIGHT
HORIZONTAL LEFT
HEAT
HEA
T
HEA
T
DOWNFLOW
HEAT