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ACCESSORY REMOTE CONTROL PANEL — This central-
station control can be set to override zone thermostat mode
settings to lock out heating or cooling for the entire unit. The
DAY/NIGHT switch and damper position knob provide in-
space, central control of damper position. Panel also houses
the filter light to indicate reduced airflow and need for clean
filters. See Fig. 29. Install remote control panel in accor-
dance with instructions shipped with this accessory.
Reheat Humidity Control — Control is achieved in
any module by wiring a humidistat in parallel with the cool-
ing thermostat. If zone thermostat drops below setting of heat-
ing thermostat because the humidistat is closed (cooling coil
is energized), the heating mode will be energized to reheat
the air in order to maintain zone space temperature. A typi-
cal humidistat hookup is shown in Fig. 30.
Optional Economizer — Adjust optional economizer
as described in Optional Economizer section on page 42.
Optional Exhaust Damper — Adjust optional ex-
haust damper as described in Optional Exhaust Damper sec-
tion on page 42.
START-UP
After unit is installed, perform the following checks and
procedures, and complete Start-Up Checklist on page CL-1.
Evaporator Fan — Fan belt and pulley are shipped at-
tached to fan assembly. The factory-installed pulley pro-
vides fan speeds as shown in Table 1. Adjust fan belt(s) as
described in Evaporator Fans and Motor section on page 41.
Also see Zone Airflow Adjustment section on page 38.
Compressor Rail Shipping Bolts — Loosen ship-
ping bolts beneath compressor rails so that rails float freely.
Do not loosen or remove bolts that attach compressors to
rails.
Refrigerant Valves — Open compressor discharge serv-
ice valve. Check that the suction service, hot gas shutoff,
and the liquid line shutoff valves are also open. See Fig. 31.
Zone Module Gas Valves (48MA) — Each zone mod-
ule has its own combination gas valve and pressure regula-
tor to which gas is supplied by one of the 2 main manual gas
valves (Fig. 32).
LEGEND
APS — Air Pressure Switch
MCR — Master Cooling Relay
MHR — Master Heating Relay
MUR — Master Unit Relay
NC — Normally Closed
NO — Normally Open
OR
Terminal (Circuit Board,
Field or Accessory Conn.)
Accessory or Field Wiring
Factory Wiring
Circuit Board Run
Fig. 29 — Remote Control Panel Accessory Connections
34