To avoid fouled machinery and extensive unit
Condensate Drain Pans — Check condensate drain pans for algae growth twice a year. If algae growth is apparent, consult a water treatment specialist for proper chemical treat- ment. Applying an algaecide every three months will typically eliminate algae problems in most locations.
Refrigerant System — Verify air and water flow rates are at proper levels before servicing. To maintain sealed circuit- ry integrity, do not install service gauges unless unit operation appears abnormal.
Check to see that unit is within the superheat and subcool- ing temperature ranges shown in Table 16. If the unit is not within these ranges, recover and reweigh in refrigerant charge.
Condensate Drain Cleaning — Clean the drain line and unit drain pan at the start of each cooling season. Check flow by pouring water into drain. Be sure trap is filled to main- tain an air seal.
Air Coil Cleaning — Remove dirt and debris from evap- orator coil as required by condition of the coil. Clean coil with a stiff brush, vacuum cleaner, or compressed air. Use a fin comb of the correct tooth spacing when straightening mashed or bent coil fins.
Condenser Cleaning —
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.
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 solu- tion. The acid can stain hands and clothing, damage concrete, and, without inhibitor, damage steel. Cover surroundings 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. 18.
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. 19.
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 con- denser overnight. For heavy scale deposit, allow 24 hours. Drain condenser and flush with clean water. Follow acid manu- facturer’s instructions.
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
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
FILL CONDENSER WITH |
| |
CLEANING SOLUTION. DO | PAIL | |
NOT ADD SOLUTION | ||
| ||
MORE RAPIDLY THAN |
| |
VENT CAN EXHAUST |
| |
GASES CAUSED BY | FUNNEL | |
CHEMICAL ACTION. | ||
| 1” | |
| PIPE | |
VENT |
| |
PIPE | 5’ APPROX | |
|
3’ TO 4’
CONDENSER
PAIL
Fig. 18 — Gravity Flow Method
PUMP | PRIMING | GAS VENT |
| CONN. | GLOBE |
|
| |
|
| VALVES |
SUCTION |
|
|
PUMP |
| SUPPLY |
|
| |
SUPPORT |
| 1” PIPE |
|
| |
|
| CONDENSER |
TANK |
| REMOVE WATER |
|
| |
|
| REGULATING VALVE |
FINE MESH |
| RETURN |
SCREEN |
|
|
Fig. 19 — Forced Circulation Method
24
