Type S Automatic Load-Transfer Control Installation, Operation, and Maintenance Instructions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LOAD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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A

 

 

 

 

 

 

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

H.V.

 

 

 

 

H.V.

 

 

 

 

 

 

 

SWITCH

 

 

 

 

SWITCH

 

 

 

 

FEEDER

 

 

 

 

 

 

 

SOURCE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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S

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CONT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Phase Voltage at the Three-Phase Sensing Type S Load Transfer Control as Related to System and Sensing Transformer Connections

%

*Assuming no feedback from the load

**Bank operates open wye-delta; requires two primary phases open for sensing

† Voltage may vary from 87 to 58% depending on load

Figure 4.

Phase voltage at the three-phase sensing Type S load-transfer control.

Customer Connections

Connection Diagram

CAUTION: Equipment Damage. Do not drill connection holes into the top of the cabinet. Connection holes in the top of the cabinet will allow moisture to seep into the control and damage the components or cause control misoperation. Failure to comply will void the control’s fac-

tory warranty.

T249.0

Diagrams for interconnecting the load-transfer control with the high-voltage switches and potential transformers are shown in Figures 5 through 8. The diagrams show

the internal wiring between the terminal blocks and the input and output receptacles on the control (available as an accessory) and the external wiring between the con- trol, transfer switches, and potential transformers. If the control is not equipped with the plugs and receptacles accessory, the cables are wired directly to the terminal blocks in the control. For the physical location of terminal blocks, refer to Figure 27.

Note: Internally wired receptacles and mating plugs for the switch operators and current sensing transformers on the switch end of the cables are provided as standard with the switches.

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