Sterling 30RA010-055 manual Maintenance, Pre-Start-Up, System Check, Minimum Cooler Flow Rates and

MAINTENANCE

Recommended Maintenance Schedule — The fol- lowing are only recommended guidelines. Jobsite conditions may dictate that maintenance schedule is performed more often than recommended.

Routine:

For machines with E-coat Condenser Coils:

•Check condenser coils for debris, clean as necessary with Sterling approved coil cleaner.

•Periodic clean water rinse, especially in coastal and industrial applications.

Every month:

•Check condenser coils for debris, clean as necessary with Sterling approved coil cleaner.

•Check moisture indicating sight glass for possible refrig- erant loss and presence of moisture.

Every 3 months (for all machines):

•Check refrigerant charge.

•Check all refrigerant joints and valves for refrigerant leaks, repair as necessary.

•Check chilled water flow switch operation.

•Check condenser coils for debris, clean as necessary with Sterling approved coil cleaner.

•Check all condenser fans for proper operation.

•Check compressor oil level.

•Check crankcase heater operation.

Every 12 months (for all machines):

•Check all electrical connections, tighten as necessary.

•Inspect all contactors and relays, replace as necessary.

•Check accuracy of thermistors, replace if greater than

± 2° F (1.2° C) variance from calibrated thermometer.

•Obtain and test an oil sample. Change oil only if necessary.

•Check to be sure that the proper concentration of anti- freeze is present in the chilled water loop, if applicable.

•Verify that the chilled water loop is properly treated.

•Check refrigerant filter driers for excessive pressure drop, replace as necessary.

•Check chilled water strainers, clean as necessary.

•Check cooler heater operation, if equipped.

•Check condition of condenser fan blades and that they are securely fastened to the motor shaft.

•Perform Service Test to confirm operation of all components.

•Check for excessive cooler approach (Leaving Chilled Water Temperature — Saturated Suction Temperature) which may indicate fouling. Clean cooler vessel if necessary.

PRE-START-UP

IMPORTANT: Before beginning Pre-Start-Up or Start-Up, complete Start-Up Checklist for 30RA Liquid Chiller at end of this publication (page CL-1 to CL-8). The Checklist assures proper start-up of a unit, and provides a record of unit condition, application requirements, system informa- tion, and operation at initial start-up.

Do not attempt to start the chiller until following checks have been completed.

System Check

1.Check all auxiliary components, such as chilled fluid pumps, air-handling equipment, or other equipment to which the chiller supplies liquid. Consult manufacturer's instructions. Verify that any pump interlock contacts have been properly installed. If the unit If the unit has

field-installed accessories, be sure all are properly in- stalled and wired correctly. Refer to unit wiring diagrams.

2.Use the Scrolling Marquee display to adjust the Cooling Set Point.

3.Fill chilled fluid circuit with clean water (with recom- mended inhibitor added) or other non-corrosive fluid to be cooled. Bleed all air out of the high points of the sys- tem. If chilled water is to be maintained at a temperature below 40 F (4.4 C) or outdoor temperatures are expected to be below 32 F (0° C), a brine of sufficient concentra- tion must be used to prevent freeze-up at anticipated suction temperatures. See Table 40.

4.Check tightness of all electrical connections.

5.Oil should be visible in the compressor sightglass(es). See Fig. 39. An acceptable oil level in the compressors is from ¼ to ¾ of sight glass. Adjust the oil level as re- quired. See Check Oil Charge section on page 60 for Sterling approved oils.

6.Electrical power source must agree with unit nameplate.

7.All condenser fan and factory installed hydronic package pump motors are three phase. Check for proper rotation of condenser fans first BEFORE attempting to start pumps or compressors. To reverse rotation, interchange any two of the main incoming power leads.

8.Be sure system is fully charged with refrigerant (see Check Refrigerant Charge section on page 75).

9.If unit is a brine unit, check to ensure proper brine con- centration is used to prevent freezing.

10.Verify proper operation of cooler and hydronic package heaters (if installed). Heaters operate at the same voltage as the main incoming power supply and are single phase. Heater current is approximately .4 amps for 380, 400, 460 and 575 v units. Heater current is approximately .8 amps for 230 v units.

Table 40 — Minimum Cooler Flow Rates and

Minimum Loop Volume

UNIT SIZE	COOLER MINIMUM			MINIMUM COOLER
		FLOW		LOOP VOLUME
30RA
	Gpm		L/s	Gal.	L
010	12		.76	40	151.2
015	16		1.01	55	207.9
018	19		1.20	48	181.4
022	26		1.64	65	245.7
025	29		1.83	71	268.3
030	33		2.08	82	309.3
035	42		2.65	102	393.1
040	45		2.80	113	449.8
042	48		3.02	119	427.1
045	52		3.28	129	487.6
050	57		3.59	142	536.6
055	65		4.10	163	616.1

START-UP AND OPERATION

NOTE: Refer to Start-Up Checklist on pages CL-1 to CL-8.

Actual Start-Up — Actual start-up should be done only under supervision of a qualified refrigeration mechanic.

1.Be sure all service valves are open.

2.Using the Scrolling Marquee display, set leaving-fluid set point (CSP.1) [Set Point, COOL]. No cooling range ad- justment is necessary.

3.Start chilled fluid pump (if not configured for cooler pump control).

4.Turn ENABLE/OFF/REMOTE CONTACT switch to ENABLE position.

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