Refrigerant Charging, Air Coil Fan Motor Removal

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.

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.

CAUTION

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

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. 32.

	FILL CONDENSER WITH
	CLEANING SOLUTION. DO	PAIL
	NOT ADD SOLUTION	PAIL
	NOT ADD SOLUTION
	MORE RAPIDLY THAN
	VENT CAN EXHAUST
	GASES CAUSED BY	FUNNEL
	CHEMICAL ACTION.	FUNNEL
		1”
		PIPE
	VENT
	PIPE	5’ APPROX
		5’ APPROX

3’ TO 4’

CONDENSER

PAIL

Fig. 32 — Gravity Flow Method

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. 33.

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.

PUMP	PRIMING	GAS VENT
	CONN.	GLOBE
		GLOBE
		VALVES
SUCTION
PUMP		SUPPLY
PUMP
SUPPORT
		1” PIPE
		CONDENSER
TANK		REMOVE WATER
		REMOVE WATER
		REGULATING VALVE
FINE MESH		RETURN
SCREEN

Fig. 33 — 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- 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 16-22. 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).