Emerson 7ADTB - Manual (Page 12)

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.