Guardian Technologies 4758 - Manual (Page 53)

SECTION 3.2
OPERATIONAL ANALYSIS
PART 3
Page 3.2-3
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.