Guardian Technologies 4456, 4390, 4389 Transfer to Standby, Transfer Action to Standby Position

V-TYPE PREPACKAGED TRANSFER SWITCHES

PART 3

SECTION 3.2

OPERATIONAL ANALYSIS

TRANSFER TO STANDBY

The generator circuit board delivers 12 volts DC to the transfer relay, via terminal 194 and back to the circuit board via terminal 23. However, circuit board action holds the Wire 23 circuit open and the transfer relay remains de-energized. On generator startup, an "engine warm-up timer" on the generator circuit board starts timing. When that timer has timed out, circuit board action completes the Wire 23 circuit to ground. The transfer relay then energizes, its normally open contacts close, and standby source voltage is delivered to the standby closing coil via Wires E1 and E2, the transfer relay (TR) contacts, limit switch (XB1), Wire "B". and a bridge rectifier. The standby closing coil energizes and the main contacts actuate to their "Standby" side.

Figure 4. Transfer Action to Standby Position

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