Optional Electric Heat; Control Wire Sizes - York ZF076 Installation Manual

5725848-XIM-A-0319
conditions, are indicated on the unit Rating Plate and the Unit
Application Data table.
380/415-3-50 units control transformers are factory
wired for 415v power supply respectively. Change tap
on transformer for 380-3-50 operation. See unit wiring
diagram.
A fused disconnect switch should be field provided for the unit.
The switch must be separate from all other circuits. Wire entry
at knockout openings require conduit fittings to comply with
NEC (in U.S.A.), CEC (in Canada) and/or local codes. Refer to
Figures 11, 12, 13 and 14 for installation location. If any of the
wire supplied with the unit must be replaced, replacement wire
must be of the type shown on the wiring diagram and the same
minimum gauge as the replaced wire.
Electrical line must be sized properly to carry the load. Use
copper conductors only. Each unit must be wired with a
separate branch circuit fed directly from the meter panel and
properly fused.
When connecting electrical power and control wiring to
the unit, waterproof type connectors MUST BE USED
so that water or moisture cannot be drawn into the unit
during normal operation. The above waterproofing
conditions will also apply when installing a field-supplied
disconnect switch.
12
Refer to the Typical Field Wiring Figures 3 and 4 and to the
appropriate unit wiring diagram for control circuit and power
wiring information.
Table 1: Control wire sizes
Wire Size
18 AWG
1. From the unit to the thermostat and back to the unit.

Optional electric heat

The factory-installed heaters are wired for single point power
supply. Power supply need only be brought into the single point
terminal block and thermostat wiring to the low voltage terminal
strip located in the upper portion of the unit control box.
These heaters are located within the central compartment of
the unit with the heater elements extending into the supply air
chamber. Refer to Figure 10 for access panel location.
Fuses are supplied, where required, by the factory. Some KW
sizes require fuses and others do not. Refer to Table 2 for
minimum Volumetric Flow Rate limitations and to Table 11 for
electrical data.
Maximum Length
46 m (150 ft)
Johnson Controls Ducted Systems
1