Transfer To Standby - Guardian 4389 Repair Manual

SECTION 3.2
OPERATIONAL ANALYSIS
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.
E1
N1A
E1
N1A
126
N1A
B
126
NO O NC
XA
COM
B
VR1
N2A
A C1
ATS
N2A
B
LEGEND
ATS-AUTOMATIC TRANSFER SWITCH
C1-UTILITY COIL & RECTIFIER
C2-GENERATOR COIL & RECTIFIER
F1,F2-5A, 600V FUSE
LC-CIRCUIT BREAKER (LOADS)
TR-TRANSFER RELAY
TS-TERMINAL STRIP
XA,XB-LIMIT SWITCHES
Page 54

TRANSFER TO STANDBY

194
194
A
23
9 9
TR
6
B
23
205
N2A
N1A
N1A
E1
N2A
205
B
N1A
N2A
E1
NC C NO
E2
COM
VR2
C2
T1 T2
T1
B E2
T2
E2
UTILITY
DC
GROUND
GENERATOR
Figure 5. Transfer Action to Standby Position
194
23
OPEN
F2
N2
F1
N1
E1
E2
E1
E2
NEUTRAL
CONNECTION
INSIDE SWITCH
E2
BLU
VIO
YLW
BRN
BRN/WHT
YLW/WHT
GRY
PNK
LC
"V-TYPE" PREPACKAGED
PART 3
TRANSFER SWITCHES
194
12Vdc TRANSER
COIL
23
TS TO
GENERATOR
CONTROL PANEL
N2
240VAC
OUTPUT
N1
BLACK
TO GENERATOR
RED
OUTPUT
CIRCUIT BREAKER
NEUTRAL (WHITE)
NEUTRAL (WHITE)
240VAC TO
RED (MAIN 2) MAIN DISTRIBUTION
PANEL
BLACK (MAIN 1)
15A/120V CIRCUIT 6
15A/120V CIRCUIT 5
20A/120V CIRCUIT 2
30A/240V CIRCUIT 1
CUSTOMER
CIRCUIT
CONNECTION
30A/240V CIRCUIT 3
15A/120V CIRCUIT 4
15A/120V CIRCUIT 7
15A/120V CIRCUIT 8