Carrier 17EX External Gear Pre-Start Checks, Recommended Motor Fastener Tightening Torques

2.Direct current (as from a welder) can be passed through the winding. The total current should not exceed approxi- mately 50% of the rated full load current. If the motor has only 3 leads, 2 must be connected together to form one circuit through the winding. In this case, one phase carries the full applied current and each of the others car- ries half of the applied current. If the motor has 6 leads (3 mains and 3 neutrals), the 3 phases should be con- nected into one series circuit.

3.Heated air can be blown either directly into the motor or into a temporary enclosure surrounding the motor. The source of heated air should preferably be electrical vs. fueled (such as kerosene), since a malfunction of the fuel burner could result in carbon entering the motor. Exer- cise caution when heating the motor with any source of heat other than self-contained space heaters. Raise the wind- ing temperature at a gradual rate to allow any entrapped moisture to vaporize and escape without rupturing the in- sulation. The entire heating cycle should extend over 15 to 20 hours.

Insulation resistance measurements can be made while the winding is being heated. However, they must be corrected to 104 F (40 C) for evaluation since the actual insulation re- sistance decreases with increasing temperature. For a new winding, the insulation resistance approximately halves for each 18° F (10° C) increase in insulation temperature above the dew point.

Motor Pre-Start Checks Ð To prevent damage to the motor, the following steps must be taken before initial start- up:

1.Remove the shaft shipping brace (if supplied).

2.For sleeve bearing motors, the oil reservoir must be ®lled with oil to the correct level. Use a rust and oxidation in- hibited, turbine grade oil. The viscosity of the oil must be 32 ISO (150 SSU) at 100 F (37.7 C). Oil capacity in each of the two bearings is 0.6 gal. (2.3 L) per bearing. Use of Carrier Oil Speci®cation PP16-0 is approved, Carrier Part No. PP23BZ091 (Mobil DTE Light or Texaco Regal R+O32).

3.If possible, the shaft should be turned over by hand to ensure that there is free rotation. On sleeve bearing mo- tors, the shaft should be moved to both extremes of its end play while it is being rotated, and the oil rings should be viewed through the viewing ports in the top of the bear- ing housing to verify free ring rotation.

4.On fan-cooled motors, the area around the external fan inlet should be checked for loose debris that could be drawn into the fan during operation.

5.All external, factory-made, bolted joints should be checked for any looseness that may have occurred in transit. Refer to Table 6 for recommended bolt torques.

Table 6 Ð Recommended Motor Fastener

Tightening Torques

	Bolt size	1¤4		5¤16		3¤8			1¤2	5¤8	3¤4			7¤8		1	11¤3		11¤2
	Grade									SAE GR 5
Torque*	Ft-lbs	3.5		7		12			31	63	115			180		275	550		960
	N.m	4.7		9.5		16			42	85	156		244			373	746	1302
	Bolt size		M4		M6			M8		M10		M12			M10		M12		M16
	Grade						DIN 8.8									DIN 12.9
Torque*	Ft-lbs		2		8			15		35		65			45		92		225
	N.m		2.7		11			20		47		88			61		125		305

*Torque values based upon dry friction.

External Gear Pre-Start Checks

There are 2 service valves on the external gear oil lines. See Fig. 27. Open both valves before starting the chiller.

External gears are shipped without oil. Before start-up, the gear must be ®lled with the proper type and amount of oil.

Before starting the external gear, check for any signs of mechanical damage, such as damaged piping or accessories. Then, follow the procedures listed below.

1.Fill the gear and auxiliary sump (if applicable) with oil to the level indicated next to the sight glass. Fill the gear to the proper level as follows. Make sure all external pip- ing, gear oil cooler, and pumps are ®lled before con®rm- ing the ®nal oil level. Fill to the oil level indicated next to the glass sight gage.

Add oil through the gear inspection cover. The inspection cover must be removed in order to add oil. Take care to seal the cover when it is replaced.

Never attempt to add or replace oil while the ex- ternal gear is running unless a vertical sight glass is in use and the running oil level has been established and marked on the sight glass. Do not ®ll beyond the indicated oil level. Excess lubrication increases the churning effect and may result in overheating and subsequent thinning of oil and possible damage to the rotating components.

2.The viscosity of the oil must be 68 ISO. Use of Carrier oil, speci®cation PP16-2 is approved (Mobil DTE Heavy Medium or Texaco Regal UR & 068; Carrier Part No. PP23BB005).

3.Check that all electrical connections have been made and are in working order. Check that all accessories are prop- erly mounted.

4.Turn the gear shafts by hand with a spanner wrench to con®rm that there are no obstructions to rotation.

5.Check that all couplings are properly aligned, mounted, and keyed on the shaft extension.

6.Check that the inspection cover is securely fastened. See Table 7 for recommended torque values.

7.For units operating in cold ambient temperatures, op- tional heaters must be turned on and the oil temperature must be allowed to rise to at least 60 F (16 C) before start-up.

8.Start the chiller under as light a load as possible. Check for oil leaks, unusual sounds, excessive vibration, and ex- cessive heat. If an operating problem develops, shut down immediately and correct the problem before restarting.

51