Typical Field Wiring; Electrical Connections; Dehumidification Control; Field Connections Power Wiring - York 12 SEER - CMA SERIES Installation Manual

7. Install TXV equalizer line in 1/8" hole previously made in vapor
line. Equalizer line should not be bottomed out in the vapor line.
Insert equalizer line at least 1/4" in the vapor line. Braze equalizer
line making sure that tube opening is not brazed closed.
Dry nitrogen should always be supplied through the tubing while it
is being brazed, because the temperature required is high enough
to cause oxidation of the copper unless an inert atmosphere is pro-
vided. The flow of dry nitrogen should continue until the joint has
cooled. Always use a pressure regulator and safety valve to insure
that only low pressure dry nitrogen is introduced into the tubing.
Only a small flow is necessary to displace air and prevent oxidation.
All connections to be brazed are copper-to-copper and should be
brazed with a phosphorous-copper alloy material such as Silfos-5 or
equivalent. DO NOT use soft solder.
Install the TXV bulb to the vapor line near the equalizer line, using the
two bulb clamps furnished with the TXV assembly. Ensure the bulb is
making maximum contact. Refer to TXV installation instruction for view
of bulb location.
In all cases, mount the TXV bulb after vapor line is brazed and has
had sufficient time to cool.
a. Bulb should be installed on a horizontal run of the vapor line if
possible. On lines under 7/8" OD the bulb may be installed on
top of the line. With 7/8" OD and over, the bulb should be
installed at the position of about 2 or 10 o'clock.
b. If bulb installation is made on a vertical run, the bulb should
be located at least 16 inches from any bend, and on the tub-
ing sides opposite the plane of the bend. The bulb should be
positioned with the bulb tail at the top, so that the bulb acts as
a reservoir.
c. Bulb should be insulated using thermal insulation provided to
protect it from the effect of the surrounding ambient tempera-
ture.
NOTE: Models with reciprocating compressors require start kits when
matched to TXV indoor coils.
SECTION V: 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 over
current protection must be supplied by the installer. Wire size should be
sized per NEC requirements.
All field wiring must USE COPPER CONDUCTORS 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 service access panel.

FIELD CONNECTIONS POWER WIRING

1. Install the proper size weatherproof disconnect switch outdoors
and within sight of the unit.
2. Remove the screws at the bottom of the corner cover. Slide corner
cover down and remove from unit. See Figure 5.
3. Run power wiring from the disconnect switch to the unit.
Unitary Products Group
4. Remove the service access panel to gain access to the unit wiring.
Route wires from disconnect through power wiring opening pro-
vided and into the unit control box as shown in Figure 5.
5. Install the proper size time-delay fuses or circuit breaker, and
make the power supply connections.
6. Energize the crankcase heater if equipped to save time by pre-
heating the compressor oil while the remaining installation is com-
pleted.
SERVICE
ACCESS
PANEL
CONTROL
WIRING
POWER
WIRING
FIGURE 5: Typical Field Wiring
FIELD CONNECTIONS CONTROL WIRING
1. Route low voltage wiring into bottom of control box as shown in
Figure 5. Make low voltage wiring connections inside the junction
box per Figures 6-8.
2. The complete connection diagram and schematic wiring label is
located on the inside surface of the unit service access panel.
3. Replace the corner cover and service access panel that were
removed in Steps 2 and 4 of the "Field Connections Power Wiring"
section.
4. All field wiring to be in accordance with national electrical codes
(NEC) and/or local-city codes.
NOTE: A Start Assist Kit is available and recommended for long line set
applications or in areas of known low voltage problems. A hard
start kit must be used if a solenoid valve accessory or non-bleed
type expansion device is installed. The TXV kits provided
through Source 1 are bleed-type.
5. Mount the thermostat about 5 ft. above the floor, where it will be
exposed to normal room air circulation. Do not place it on an out-
side wall or where it is exposed to the radiant effect from exposed
glass or appliances, drafts from outside doors or supply air grilles.
6. Route the 24-volt control wiring (NEC Class 2) from the outdoor
unit to the indoor unit and thermostat.
NOTE: To eliminate erratic operation, seal the hole in the wall at the
thermostat with permagum or equivalent to prevent air drafts
affecting the operation of in the thermostat.

DEHUMIDIFICATION CONTROL

A dehumidification control accessory 2HU06700124 may be used with
variable speed air handlers or furnaces in high humidity areas. This
control works with the variable speed indoor unit to provide cooling at a
reduced air flow, lowering evaporator temperature and increasing latent
capacity. The humidistat in this control opens the humidistat contacts on
humidity rise. To install, refer to instructions packaged with the acces-
sory and Figures 6-9. Prior to the installation of the dehumidification
control, the jumper across the HUMIDISTAT terminals on the indoor
variable speed air handler or furnace CFM selection board must be
removed.
During cooling, if the relative humidity in the space is higher than the
desired set point of the dehumidification control, the variable speed
blower motor will operate at lower speed until the dehumidification con-
trol is satisfied. A 40-60% relative humidity level is recommended to
achieve optimum comfort.
If a dehumidification control is installed, it is recommended that a mini-
mum air flow of 325 cfm/ton be supplied at all times.
035-19946-001 Rev. B (0804)
CORNER
COVER
5