Trane RTUB 207-224 Operation, Pre-start checkout, Installation Checklist, Unit Voltage Phasing

Operation

Pre-start checkout

Installation Checklist

When installation is complete, but prior to putting the unit into service, the following pre-start procedures must be reviewed and verified:

•Inspect all wiring connections to be sure they are clean and tight.

￿WARNING

Disconnect all electric power, including remote disconnects, before servicing. Failure to disconnect power before servicing can cause severe personal injury or death.

￿CAUTION

•Check the tightness of all connections in the compressor power circuit (disconnects, terminal block, contactors, compressor junction box terminals,…). Loose connections can cause overheating at the connections and undervoltage conditions at the compressor motor.

•Open all refrigerant valves in the discharge, liquid, oil, and oil return lines.

￿CAUTION

Do not operate the unit with the compressor, oil discharge, liquid-line service valves, or the manual shutoff on the refrigerant supply to the auxiliary coolers "CLOSED." Failure to have these "OPEN" may cause serious compressor damage.

•Check the power-supply voltage to the unit at the main-power fused- disconnect switch. Voltage must be within the voltage utilization range and also stamped on the unit nameplate. Voltage imbalance must not exceed 2%.

•Check the unit power phasing L1- L2-L3 in the starter to ensure that it has been installed in an "A B-C" phase sequence.

￿CAUTION

Improper power phasing can result in equipment damage due to reverse rotation.

Do not use untreated or improperly- treated water. Equipment damage may occur.

•Fill the evaporator chilled-water circuit. Vent the system while it is being filled. Open the vents on the top of the evaporator water box while filling and close when filling is completed.

The use of improperly-treated or untreated water in this equipment may result in scaling, erosion, corrosion, algae, or slime.The services of a qualified water- treatment specialist should be engaged to determine what treatment, if any, is advisable.Trane's warranty specifically excludes liability of corrosion, erosion, or deterioration ofTrane equipment. Trane assumes no responsibilities for the results of the use of untreated or improperly-treated water, or saline or brackish water.

•Close the fused-disconnect switch(es) that supplies power to the chilled-water pump starter.

•Start the chilled-water pump to begin circulation of the water. Inspect all piping for leakage and make any necessary repairs.

•With water circulating through the system, adjust the water flow and check the water pressure drop through the evaporator.

•Adjust the chilled-water flow switch for proper operation.

￿WARNING

Use extreme caution when performing the following procedure with power applied. Failure to do so can result in personal injury or death.

•Reapply power to complete the procedures.

•Prove all Interlock and Interconnecting Wiring Interlock and External as described in the Installation section.

•Check and set, as required, all UCM-CLD menu items.

•Stop the chilled-water pump.

•Energize the compressor and oil separators 24 hours prior to unit startup.

Unit Voltage Power Supply Voltage to the unit must meet the criteria given in the Installation section. Measure each leg of the supply voltage at the main power fused-disconnect switch for the unit. If the measured voltage on any leg is not within the specified range, notify the supplier of the power and correct the situation before operating the unit.

￿CAUTION

Provide adequate voltage to the unit. Failure to do so can cause control components to malfunction and shorten the life of relay contact, compressor motors and contactors.

Unit Voltage Imbalance Excessive voltage imbalance between the phases of a three-phase system can cause motors to overheat and eventually fail.The maximum allowable imbalance is 2%. Voltage imbalance is determined using the following calculations:

%Imbalance = [(Vx - V ave) x 100]/V ave

V ave = (V1 + V2 + V3)/3

Vx = phase with the greatest difference from V ave (without regard to the sign)

For example, if the three measured voltages are 391, 407, and 402 volts, the average would be:

(391+407+402)/3 = 400

The percentage of the imbalance is then:

[100(400-391)]/400 = 2.25%

This exceeds the maximum allowable (2%) by 0.25%

Unit Voltage Phasing

It is imperative that L1, L2, and L3 in the starter be connected in the A-B-C phase sequence to prevent equipment damage due to reverse rotation.

It is important that proper rotation of the compressors be established before the unit is started. Proper

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