BYPASSING & ISOLATING
(continued)
3---3
ISOLATING THE ATS
Isolating is required before any service work can be
performed on the automatic transfer switch (ATS). Refer
to Figures 3–9, 3–10, 3–11, and 3–12.
1. Bypass the closed automatic transfer switch contacts.
See
BYPASSING
on pages 3–1 and 3–2.
2. Turn the Isolation Handle counterclockwise (approx.
8 turns) until window shows
TEST
. The
TS Test
amber
light should come on. The ATS can be tested now
without load interruption (see page 2–1).
E
L
N
Automatic Transfer Switch
Bypass Switch
Turn crank
counter-
clockwise
until
window
shows
TEST.
Figure 3–9.
CONNECTED
to
TEST
position.
TS CONNECTED
Middle amber light
should be on.
TS TEST
TS ISOLATED
position
window
CONN
TEST
ISOLATE
counterclockwise – draws
out the transfer switch
Figure 3–10. Isolation Handle turned to
TEST
.
NOTE: In the TEST position the transfer
switch solenoid operator circuit is energized
through secondary disconnects.
Hazardous voltage capable of causing
electrical shock, burns, or death;
do not touch any control circuit terminals.
3. Continue turning Isolation Handle counterclockwise
(approx. 6 turns) until the window shows
ISOLATE
.
The
TS Isolated
amber light should come on.
E
L
N
Turn crank
counter-
clockwise
until
window
shows
ISOLATE.
Automatic Transfer Switch
Bypass Switch
Figure 3–11.
TEST
to
ISOLATE
position.
TS CONNECTED
Lower amber light
should be on.
TS TEST
TS ISOLATED
position
window
CONN
TEST
ISOLATE
counterclockwise – draws
out the transfer switch
Figure 3–12. Isolation Handle turned to
ISOLATE
.
