SERVICE
WARNING: Before performing service or mainte- nance operations on unit, turn off main power switch to unit and install lockout tag on disconnect switch. Turn off acces- sory heater power switch if applicable. Electrical shock could cause personal injury.
I. CLEANING
Inspect unit interior at beginning of each heating and cooling season and as operating conditions require. Remove unit top panel and/or side panels for access to unit interior.
A. Evaporator Coil
Clean as required with a commercial coil cleaner.
B. Condenser Coil
Clean condenser coil annually and as required by location and
C. Condensate Drain
Check and clean each year at start of cooling season. In win- ter, keep drains and trap dry.
D. Filters
Clean or replace at start of each heating and cooling season, or more often if operating conditions require. Refer to Table 1 for type and size.
E. Outdoor-Air Inlet Screens
Clean screens with steam or hot water and a mild detergent. Do not use throwaway filters in place of screens.
II. LUBRICATION
A. Compressors
Each compressor is charged with the correct amount of oil at the factory. Conventional white oil (Sontext 200LT) is used. White oil is compatible with 3GS oil, and 3GS oil may be used if the addition of oil is required. See compressor name- plate for original oil charge. A complete recharge should be four ounces less than the original oil charge. When a com- pressor is exchanged in the field it is possible that a major portion of the oil from the replaced compressor may still be in the system. While this will not affect the reliability of the replacement compressor, the extra oil will add rotor drag and increase power usage. To remove this excess oil, an access valve may be added to the lower portion of the suction line at the inlet of the compressor. The compressor should then be run for 10 minutes, shut down, and the access valve opened until no oil flows. This should be repeated twice to make sure the proper oil level has been achieved.
B. Fan Shaft Bearings
For size 155 units, bearings are permanently lubricated. No field lubrication is required. For size 180 and 240 units, the bearings are of the pillow block type and have grease fit- tings. The bearing opposite the motor end has an extended tube line so it can be lubricated from the motor side. Lubri- cate the bearings twice annually.
Typical lubricants are given below:
MANUFACTURER | LUBRICANT |
Texaco | Regal |
Mobil | Mobilplex EP No. 1 |
Sunoco | Prestige 42 |
Texaco | Multifak 2 |
*Preferred lubricant because it contains rust and oxidation inhibitors.
C. Condenser and Evaporator-Fan Motor Bearings
The condenser and
III.EVAPORATOR FAN PERFORMANCE ADJUSTMENT (Fig. 30-32)
Fan motor pulleys are factory set for speed shown in Table 1.
To change fan speeds:
1.Shut off unit power supply.
2.a. Size 155 Only: Loosen belt by loosening fan motor mounting plate nuts.
b. Size 180 and 240 Only: Loosen nuts on the 2 car- riage bolts in the motor mounting base. Install jacking bolt and plate under motor base (bolt and plate are shipped in installer’s packet). See Fig. 32. Using bolt and plate, raise motor to top of slide and remove belt. Secure motor in this position by tight- ening the nuts on the carriage bolts.
3.Loosen
4.Screw movable flange toward fixed flange to increase speed and away from fixed flange to decrease speed. Increasing fan speed increases load on motor. Do not exceed maximum speed specified in Table 1.
See Table 8 for air quantity limits.
5.Set movable flange at nearest keyway of pulley hub and tighten setscrew. (See Table 1 for speed change for each full turn of pulley flange.)
6.Replace and tighten belts. See Belt Tension Adjust- ment section on page 27.
To align fan and motor pulleys:
1.Loosen fan pulley setscrews.
2.Slide fan pulley along fan shaft.
3.Make angular alignment by loosening motor from mounting plate.
IV. EVAPORATOR FAN SERVICE AND REPLACEMENT
A. 551A155 Units (See Fig. 31)
NOTE: To remove belts only, follow Steps
1.Remove filter and
2.Remove unit top panel.
3.Loosen carriage nuts A and B holding motor mount assembly to fan scroll side plates.
4.Loosen screw C.
5.Rotate motor mount assembly (with motor attached) as far as possible away from evaporator coil.
6.Remove belt.
7.Rotate motor mount assembly back past original position toward evaporator coil.
8.Remove motor mounting nuts D and E (both sides).
9.Lift motor up through top of unit.
10.Reverse above procedure to reinstall motor.
11.Check and adjust belt tension as necessary.
B. 551A180,240 Units (See Fig. 32)
The 551A180,240 units use a fan motor mounting system that features a
1.Remove the
2.Remove the center post (located between the evapora- tor fan and heating control access panels) and all screws securing it.