Carrier 50PCH specifications Refrigerant Charging, A50-6286ef, ’ to 4’

Air Coil Cleaning — Remove dirt and debris from evap- orator coil as required by condition of the coil. A 10% solution of dishwasher detergent and water is recommended for cleaning both sides of the coil, followed by a thorough water rinse. Clean coil with a stiff brush, vacuum cleaner, or com- pressed air. Use a fin comb of the correct tooth spacing when straightening mashed or bent coil fins.

Condenser Cleaning — Water-cooled condensers may require cleaning of scale (water deposits) due to improperly maintained closed-loop water systems. Sludge build-up may need to be cleaned in an open water tower system due to induced contaminants.

FORCED CIRCULATION METHOD — Fully open vent pipe when filling condenser. The vent may be closed when condenser is full and pump is operating. See Fig. 31.

Regulate flow to condenser with a supply line valve. If pump is a nonoverloading type, the valve may be fully closed while pump is running.

For average scale deposit, allow solution to remain in condenser overnight. For heavy scale deposit, allow 24 hours. Drain condenser and flush with clean water. Follow acid manu- facturer’s instructions.

Local water conditions may cause excessive fouling or pitting of tubes. Condenser tubes should therefore be cleaned at least once a year, or more often if the water is contaminated.

Proper water treatment can minimize tube fouling and pitting. If such conditions are anticipated, water treatment analysis is recommended. Refer to the Carrier System Design Manual, Part 5, for general water conditioning information.

PUMP PRIMING CONN.

SUCTION

PUMP

SUPPORT

GAS VENT

GLOBE

VALVES

SUPPLY

1” PIPE

a50-6287ef

CONDENSER

CAUTION

Follow all safety codes. Wear safety glasses and rubber gloves when using inhibited hydrochloric acid solution. Observe and follow acid manufacturer’s instructions.

TANK

FINE MESH SCREEN

REMOVE WATER

REGULATING VALVE

RETURN

Clean condensers with an inhibited hydrochloric acid solution. The acid can stain hands and clothing, damage concrete, and, without inhibitor, damage steel. Cover sur- roundings to guard against splashing. Vapors from vent pipe are not harmful, but take care to prevent liquid from being carried over by the gases.

Warm solution acts faster, but cold solution is just as effec- tive if applied for a longer period.

GRAVITY FLOW METHOD — Do not add solution faster than vent can exhaust the generated gases.

When condenser is full, allow solution to remain overnight, then drain condenser and flush with clean water. Follow acid manufacturer’s instructions. See Fig. 30.

Fig. 31 — Forced Circulation Method

Checking System Charge — Units are shipped with full operating charge. If recharging is necessary:

1.	Insert thermometer bulb in insulating rubber sleeve on
	liquid line near filter drier. Use a digital thermometer for
	all temperature measurements. DO NOT use a mercury
	or dial-type thermometer.
2.	Connect pressure gage to discharge line near compressor.
3.	After unit conditions have stabilized, read head pressure
	on discharge line gage.
	NOTE: Operate unit a minimum of 15 minutes before
	checking charge.
4.	From standard field-supplied Pressure-Temperature
	chart for R-410A, find equivalent saturated condens-

FILL CONDENSER WITH CLEANING SOLUTION. DO NOT ADD SOLUTION MORE RAPIDLY THAN VENT CAN EXHAUST GASES CAUSED BY CHEMICAL ACTION.

VENT

PIPE

3’ TO 4’

PAIL

FUNNEL

1”

PIPE

5’ APPROX

CONDENSER

ing temperature.

5. Read liquid line temperature on thermometer; then

subtract from saturated condensing temperature. The dif-

ference equals subcooling temperature.

6. Compare the subcooling temperature with the normal

temperature listed in Tables 15-25. If the measured liquid

line temperature does not agree with the required liquid

line temperature, ADD refrigerant to raise the tempera-

ture or REMOVE refrigerant (using standard practices) to

lower the temperature (allow a tolerance of ± 3° F).

Refrigerant Charging

WARNING

a50-6286ef

PAIL

Fig. 30 — Gravity Flow Method

To prevent personal injury, wear safety glasses and gloves when handling refrigerant. Do not overcharge system — this can cause compressor flooding.

NOTE: Do not vent or depressurize unit refrigerant to atmosphere. Remove and recover refrigerant following accepted practices.

39