Emerson 7ACTB manual Bypassing & Isolating, continued

BYPASSING & ISOLATING

(continued)

ISOLATING THE ATS

Isolating is required before any service work can be performed on the automatic transfer switch (ATS). Refer

CONN

position window

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).

Bypass Switch	E
Turn crank
counter-
clockwise	L
until
window
shows
TEST.
	N
Automatic Transfer	Switch
Figure 3–4. CONNECTED to TEST position.

3.Continue turning Isolation Handle counterclockwise (approx. 7 turns) until the window shows ISOLATE.

Bypass Switch	E
Turn crank
counter-
clockwise	L
until
window
shows
ISOLATE.
	N
Automatic Transfer 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.

TEST

ISOLATE

unfold crank

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.

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