515.28-N3Y
8
Unitary Products Group
side doors or supply air grilles.
After the thermostat is mounted, route the 24-volt control wir-
ing (NEC Class 2) from the thermostat to the indoor air han-
dler and outdoor unit. Route the control wiring into the
grommeted hole in the bottom of control box of the outdoor
unit and run along the outside of the electrical barrier to con-
trol. Connect leads to the screw terminals on the control as
shown in Figure 7.
Interconnecting control wiring must be a minimum of No. 18
AWG color coded insulated wires. If wire lengths increase
more than 90 feet, use No. 16 AWG wires, to prevent exces-
sive voltage drop.
NOTE:
To eliminate erratic operation, seal the hole in the
wall at the thermostat with permagum or equivalent
to prevent air drafts affecting the anticipators in the
thermostat.
EVACUATION
It will be necessary to evacuate the system if the unit has
developed a leak during shipment or was, for any other rea-
son, opened to the atmosphere. If a leak is suspected, leak
test to locate the leak. Repair the leak and test again.
To verify if the system has no leaks, simply close the valve to
the vacuum pump suction to isolate the pump and hold the
system under vacuum. Watch the micron guage for a few
minutes. If the micron gauge indicates a steady and continu-
ous rise, it’s an indication of a leak. If the gauge shows a rise,
then levels off after a few minutes and remains fairly con-
stant, its an indication that the system is leak free but still
contains moisture and may require further evacation if the
reading is above 500 microns.
SYSTEM CHARGE
The factory charge in the outdoor unit includes enough
charge for the unit and a most sold matched evaporator.
FIGURE 7 : TYPICAL FIELD WIRING (AIR HANDLER / ELECTRICAL HEAT)
Refrigerant charging should only be carried out by a
qualified air conditioning contractor with proper certi-
fication
Refrigerant charging should only be carried out bya
qualified air conditioning contractor with proper certi-
fication.
