ELECTRICAL CONNECTIONS
GENERAL INFORMATION & GROUNDING
Check the electrical supply to be sure that it meets the values
specified on the unit nameplate and wiring label.
Power wiring, control (low voltage) wiring, disconnect switches
and overcurrent protection to be supplied by the installer. See
Table 1 for proper sizes. Wire size should be at least equal to
or greater than the size shown in Table 1.
CAUTION: All field wiring must USE COPPER CONDUC-
TORS ONLY and be in accordance with Local,
National Fire, Safety & Electrical Codes. This
unit must be grounded with a separate ground
wire in accordance with the above codes.
The complete connection diagram and schematic wiring label
is located on the inside surface of the unit electrical box cover.
Field wiring is also shown in Figure 1.
NOTE: The wires for the operation of the lead compressor are
solid in color. For differentiation, the wires of the fol-
lower compressor are basically the same in color, but
striped.
POWER WIRING
1. Install the proper size weatherproof disconnect switch out-
doors and within sight of the unit.
2. Run power wiring from the disconnect switch to the unit.
3. Remove the control box cover to gain access to the unit
wiring. Route wires from disconnect through power wiring
opening provided and into the unit control box as shown in
Figure 8.
4. Install the proper size time-delay fuses or circuit breaker,
and make the power supply connections.
5. Energize the crankcase heater to save time by preheating
the compressor oil while the remaining installation is com-
pleted.
ACCESSORY WIRING
The electrical accessories available for this unit are a two stage
cooling thermostat and an optional De-humidification Control.
Refer to the individual instructions packaged with the accesso-
ries for installation.
THERMOSTAT MOUNTING / WIRING
This condensing unit must be installed with the factory recom-
mended thermostat, 2ET04700224 or any conventional two-
stage cooling thermostat. The difference between the two
stages of a typical two-stage thermostat is 2 - 2.5
°
F.
The thermostat should be located about 5 ft. above the floor,
where it will be exposed to normal room air circulation. Do not
place it on an outside wall or where it is exposed to the radiant
effect from exposed glass or appliances, drafts from outside
doors or supply air grilles.
After the thermostat is mounted, route the 24-volt control wiring
(NEC Class 2) from the thermostat to the indoor varible speed
air handler and outdoor unit. Route the control wiring into the
grommetted hole in the bottom of control box of the outdoor
unit. Using wire nuts connect to leads provided in unit control
box as per Figure 8.
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 excessive
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.
DE-HUMIDIFICATION CONTROL
A de-humidification control accessory 2HU06700124 may be
required in high humidity areas. This control provides cooling
at a reduced air flow, lowering evaporator temperature and
increasing latent capacity. To install, refer to instructions pack-
aged with the accessory. Prior to the installation of the de-hu-
midification control, the jumper across the de-humidification
control terminals on the indoor variable speed air handler
terminal board must be removed. See Figure 10. Refer to
Figure 9 for wiring details.
During first or second stage cooling, if the relative humidity in
the space is higher than the desired set point of the de-humidi-
fication control, the variable speed blower motor will operate at
a lower speed until the de-humidification control is satisfied. A
40 - 60% relative humidity level is recommended to achieve
optimum comfort.
NOTE: If a de-humidification control is installed, it is recom-
mended that a minimum air flow of 325 cfm/ton be
supplied at all times.
550.37-N1Y
6
Central Environmental Systems
