Carrier 48MA/50ME016-040 specifications Start-Up

ACCESSORY REMOTE CONTROL PANEL Ð 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 ®lter light to indicate reduced air¯ow and need for clean ®lters. See Fig. 29. Install remote control panel in accor- dance with instructions shipped with this accessory.

Reheat Humidity Control Ð 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 Ð Adjust optional economizer as described in Optional Economizer section on page 42.

Optional Exhaust Damper Ð 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 Ð 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 Air¯ow Adjustment section on page 38.

Compressor Rail Shipping Bolts Ð Loosen ship- ping bolts beneath compressor rails so that rails ¯oat freely. Do not loosen or remove bolts that attach compressors to rails.

Refrigerant Valves Ð 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) Ð 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	Ð Air Pressure Switch	OR	Terminal (Circuit Board,
MCR Ð Master Cooling Relay			Field or Accessory Conn.)
MHR Ð Master Heating Relay
			Accessory or Field Wiring
MUR	Ð Master Unit Relay
			Factory Wiring
NC	Ð Normally Closed
NO	Ð Normally Open		Circuit Board Run

Fig. 29 Ð Remote Control Panel Accessory Connections

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