Guardian Technologies 4758, 4456, 4390, 4389, 4760, 4759 manual Utility Source Voltage Failure

SECTION 3.2

OPERATIONAL ANALYSIS

PART 3

V-TYPE PREPACKAGED TRANSFER SWITCHES

UTILITY SOURCE VOLTAGE FAILURE

If utility source voltage should drop below a preset value, the generator circuit board will sense the dropout. That circuit board will then initiate generator cranking and startup after a time delay circuit times out.

Figure 3 is a schematic representation of the transfer switch with generator power available, waiting to transfer.

❏Generator voltage available E1, E2.

❏Circuit board action holding Wire 23 open to ground.

❏Power available to standby coil C2, upon closure of TR, normally open contacts (9 & 6) will close and initiate a transfer.

Figure 3. Generator Power Available, Waiting to Transfer.

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