Inspection and Installation

3.7.1VFD Control Condensers (TCDV) only

The installer/startup technician must determine the type of 3-phase supply power being used for the VFD Control Condenser: Wye-connected power or Delta- connected power.

Wye-connected power has two different voltages that can be measured: Phase-to-Phase voltage (this is equal to the nominal input voltage) and Phase-to-Neutral voltage (typically used for small single phase loads (120 VAC or 277 VAC). See Figure 16.

Delta-connected power only has one voltage level that can be measured: Phase-to-Phase. See Figure 17.

3.7.2Wye-Connected Power Supply

No control changes are required if the Liebert VFD Control Condenser will be operated with Wye-con- nected power.

Figure 16 Wye-connected power diagram

 

Phase A

Winding

Phase B

B

 

Winding

A

Neutral

Winding

C Phase C

3.7.3Delta-Connected Power Supply

Figure 17 Delta-connected power diagram

Phase A

Winding

WindingA-B

C-A

Phase B

Winding B-C

Phase C

21

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Liebert 205 251, 83, 104 165 VFD Control Condensers Tcdv only, Wye-Connected Power Supply, Delta-Connected Power Supply