Carrier 90MA/MF/MU manual R-22Units, R-134aUnits, R-407CUnits

5.10Evaporator Fan Motor Removal

a. Shut off unit main power supply.

WARNING

Lock open and tag unit disconnect before working on fan motor. Remove fuses and take them with you after noting this on tag.

CAUTION

Before attempting to remove fan motors or motor mounts, place a piece of plywood over evaporator coils to prevent coil damage.

b. Loosen motor hold down bolts on mounting bracket so that fan belt can be removed. Motor power wires need not be disconnected from motor terminals be- fore motor is removed from unit.

c. Loosen but do not remove the 2 motor mounting bracket bolts on left side of bracket.

d. Slide motor/bracket assembly to extreme right, re- move bolts and lift out through space between fan scroll and side. Rest motor on a high platform such as a step ladder. Do not allow motor to hang by its power wires.

5.11Pressure Relief Device

All units are equipped with a fusible-plug type safety relief device on the refrigerant tubing. The relief setting is 197 _F to 203 _F on all units.

5.12Crankcase Heater

A crankcase heater is supplied on the 008 & 012 size units and on all 134a units. The heater prevents liquid refrigerant from accumulating in the compressor crankcase during extended shutdown periods. Heater is automatically energized whenever unit main power is on and compressor is stopped. Heater is de-energized when compressor starts.

Do not shut off main power supply for an extended period except for servicing unit. Turn on power supply for at least 24 hours after an extended shutdown before starting compressor. Refer to “Operation”.

5.13Cycle--LocTM-- Protection Device

All units are equipped with Cycle-LOC current-sensing lockout relay. This device will lock out the compressor after any safety trip (discharge pressure switch, suction-pressure switch, or internal overload of the compressor). Check reason for lockout before resetting the device. Refer to unit label wiring diagram. To reset, turn the system switch to OFF, then back to COOL.

5.14Discharge and Suction Pressure Switches

Refer to Table 1 through Table 2 for opening and closing settings for these safety devices.

The discharge pressure switch is located on the compressor on the 008 & 012 size units and on the discharge line on all other units. The suction pressure switch is located on top of the compressor on 06DR compressor equipped units and on the suction line on all other units.

5.15Oil Charge

All units are factory charged with oil. On 06D compressors, observe the oil level in the sight glass at start-up. If unit oil level is below sight glass, add oil until level reaches approximately 1/4 sight glass.

If oil charge is above sight glass, do not remove any oil until the compressor crankcase heater has been energized for at least 24 hours.

When additional oil or a complete charge is required, use only the following Carrier approved oil.

R-22 Units

Design Series One 204/206 size units Witco part number 999-5170-55

Design Series One 208/212 size units and all Design Series Two

Witco - Suniso 3GS

Calumet - RO-15

R-134a Units

Castrol - Icematic E68

ICI - Emkarate RL68HP

R-407C Units

004 and 006	Copeland Ultra 22CC
	Mobil Artic EAL 22CC
	ICI (Virginia KMP) Emkarate
	RL32C
	Thermal Zone 22CC
008 and 012	Castrol - Icematic E68
	ICI - Emkarate RL68HP

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