BYPASSING & ISOLATING
(continued)
3---2
ISOLATING THE ATS
Isolating is required before any service work can be
performed on the automatic transfer switch (ATS). Refer
to Figures 3–4, 3–5, 3–6, and 3–7.
1. Bypass the closed automatic transfer switch contacts.
See
BYPASSING
on page 3–1.
Align position indicator. Do not leave
the handle in an intermediate position.
2. Turn the Isolation Handle counterclockwise (approx.
16 turns) until window shows
TEST
. 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 3–4.
CONNECTED
to
TEST
position.
3. Continue turning Isolation Handle counterclockwise
(approx. 7 turns) until the window shows
ISOLATE
.
E
L
N
Turn crank
counter-
clockwise
until
window
shows
ISOLATE.
Automatic Transfer Switch
Bypass Switch
Figure 3–5.
TEST
to
ISOLATE
position.
4. Open the lower enclosure door. Pull out the side rail
carriage then roll out the transfer switch. It can be
safely inspected in this position. The transfer switch
can also be removed for easier maintenance opera-
tions.
unfold
crank
position
window
CONN
TEST
ISOLATE
counterclockwise – draws out
transfer switching device
Figure 3–6. Isolation Handle.
NOTE: In the TEST position the transfer
switching device 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.
Figure 3–7.Transfer switching device isolated
and pulled out for inspection.
See page 2–2 for maintenance handle use. A lifting yoke
kit 607064 is available to facilitate lifting by using an
overhead crane or similar equipment.
Transfer Switch weighs 350–450 lbs.
Use lifting device 607064 or other device
capable of lifting this weight to avoid
personal injury or equipment damage.
