UPS 120, UPS 150, UPS 250, UPS 300, UPS 301, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supplies Caterpillar

Description

Illustration 1	g01269271
View of 4-Wire Zig Zag Transformer (1) Zig Zag Transformer

The "T5" Zig Zag Transformer is located on the floor of the SMS Cabinet in a 4-wire installation. The "T5" Zig Zag Transformer is located on the rear panel in a 3-wire installation.

The transformer is required for establishing the neutral point of the UPS 3-phase output when the following conditions occur:

• discharge mode of the system

• disconnection of the utility input

Illustration 2	g01269273
View of the 3-Wire Zig Zag Transformer Rear Panel (2) Zig Zag Transformer

Removal Procedure and Installation Procedure for the Zig Zag Transformer

Temperature Switch (4-Wire)

There is a 150 °C (302 °F) "TS1" Temperature Switch attached to the 4-wire "T5" Transformer. The "TS1" is connected to the Circuit Breaker (CB2) on the left panel. If the temperature of the "T5" Transformer reaches 150 °C (302 °F), the following actions will occur:

• The switch will close.

• The circuit breaker will trip.

• The circuit breaker will shut down power to the transformer.

Current Transformers (4-Wire)

There are three circular 5000:1 Current Transformers (CTs) surrounding each of the Zig Zag Transformer Phase cables located at the bottom of the cabinet in a 4-wire installation. These current transformers relay a telemetry signal to the Zig Zag Controller board (ZZC).

Illustration 3	g01269315
View of the 3-Wire Zig Zag Wire Connections