The rotation direction of the motor is shown either on the motor nameplate or on the certi®ed drawing. Information on the required phase rotation of the incoming power for this motor may also be found on the nameplate or drawing. If either is unknown, the correct sequence can be determined as follows. While the motor is uncoupled from the load, start the motor and observe the direction of rotation. Allow the motor to achieve full speed before disconnecting it from the power source. Refer to Motor Pre-Start Checks (page 51) for information concerning initial start-up. If the resulting rotation is incorrect, it can be reversed by interchanging any 2 incoming cables.
Motor Auxiliary Devices Ð Auxiliary devices such as resistance temperature detectors, thermocouples, thermo- guards, etc., generally terminate on terminal blocks located in the auxiliary terminal box on the motor. Other devices may terminate on their own enclosures elsewhere on the mo- tor. Such information can be obtained by referring to the cer- ti®ed drawing. Information regarding terminal designations and the connection of auxiliary devices can be obtained from the auxiliary drawings referenced by the outline drawing.
If the motor is provided with internal space heaters, to ensure proper heater operation, the incoming voltage sup- plied to them must be exactly as shown by either the name- plate on the motor or the outline drawing. Exercise caution any time contact is made with the incoming space heater cir- cuit, because space heater voltage is often automatically ap- plied when the motor is shut down.
Open Oil Circuit Valves Ð Check that the oil ®lter isolation valves for both the compressor and external gear are open by removing the valve cap and checking the valve stem. (See Scheduled Maintenance, Changing the Oil Fil- ters, page 76.)
Tighten All Gasketed Joints and Guide Vane Shaft Packing Ð Gaskets and packings normally relax by the time the chiller arrives at the jobsite. Tighten all gas- keted joints and the guide vane shaft packing to ensure a leak-tight chiller.
NOTE: Check the chiller cold alignment. Refer to Chiller Alignment in the General Maintenance section, page 71.
Check Chiller Tightness Ð Figure 25 outlines the proper sequence and procedures for leak testing.
17EX chillers may be shipped with the refrigerant con- tained in the economizer/storage vessel and the oil charge shipped in the compressor. The cooler/condenser vessels have a 15 psig (103 kPa) refrigerant charge. Units may also be ordered with the refrigerant shipped separately, along with a 15 psig (103 kPa) nitrogen-holding charge in each vessel.
To determine if there are any leaks, the chiller should be charged with refrigerant. Use an electronic leak detector to check all ¯anges and solder joints after the chiller is pres- surized. If any leaks are detected, follow the leak test procedure.
If the chiller is spring isolated, keep all springs blocked in both directions in order to prevent possible piping stress and damage during the transfer of refrigerant from vessel to ves- sel during the leak test process or any time refrigerant is trans- ferred. Adjust the springs when the refrigerant is in operat- ing condition and when the water circuits are full.
Refrigerant Tracer Ð Carrier recommends using an en- vironmentally acceptable refrigerant tracer for leak testing with an electronic detector.
Ultrasonic leak detectors also can be used if the chiller is under pressure.
Do not use air or oxygen as a means of pressurizing the chiller. Some mixtures of HFC-134a and air can un- dergo combustion.
Leak Test the Chiller Ð Due to regulations regarding refrigerant emissions and the difficulties associated with sepa- rating contaminants from refrigerant, Carrier recommends the following leak test procedures. See Fig. 25 for an outline of the leak test procedures. Refer to Tables 5A and 5B for refrigerant pressure/temperature values and to the Pumpout and Refrigerant Transfer Procedures section, page 63.
1.If the pressure readings are normal for the chiller condition:
a.Evacuate the nitrogen holding charge from the ves- sels, if present.
b.Raise the chiller pressure, if necessary, by adding re- frigerant until the pressure is at an equivalent satu- rated pressure for the surrounding temperature. Follow the pumpout procedures in the Pumpout and Refrig- erant Transfer Procedures section, page 63.
Never charge liquid refrigerant into the chiller if the pres- sure in the chiller is less than 35 psig (241 kPa). Charge as a gas only, with the cooler and condenser pumps run- ning, until this pressure is reached, using PUMPDOWN/ LOCKOUT and TERMINATE LOCKOUT mode on the PIC. Flashing of liquid refrigerant at low pressures can cause tube freeze-up and considerable damage.
Run the chiller water pumps whenever transferring, re- moving, or charging refrigerant.
c.Leak test chiller as outlined in Steps 3 - 9.
2.If the pressure readings are abnormal for chiller conditions:
a.Prepare to leak test chillers shipped with refrigerant (Step 2h).
b.Check for large leaks by connecting a nitrogen bottle and raising the pressure to 30 psig (207 kPa). Soap test all joints. If the test pressure holds for 30 minutes, prepare to test for small leaks (Steps 2g - h).
c.Plainly mark any leaks that are found.
d.Release the pressure in the system.
e.Repair all leaks.
f.Retest the joints that were repaired.
g.After successfully completing the test for large leaks, remove as much nitrogen, air, and moisture as pos- sible, given the fact that small leaks may be present in the system. This can be accomplished by following the dehydration procedure, outlined in the Chiller Dehydration section, page 49.
h.Slowly raise the system pressure to the equivalent satu- rated pressure for the surrounding temperature but no less than 35 psig (241 kPa) by adding HFC-134a refrigerant. Proceed with the test for small leaks (Steps 3-9).
3.Check the chiller carefully with an electronic leak detec- tor, or soap bubble solution.
