Emerson 7ADTB manual BYPASSING & ISOLATING continued, Isolating The Ats

BYPASSING & ISOLATING (continued)

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).

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

Figure 3–9. CONNECTED to TEST position.

TS CONNECTED

Middle amber light
should be on.	TS TEST
	TS ISOLATED

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.

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

Figure 3–11. TEST to ISOLATE position.

	TS CONNECTED
	TS TEST
Lower amber light	TS ISOLATED
should be on.

position	CONN	counterclockwise – draws
window	TEST	out the transfer switch
	ISOLATE

Figure 3–10. Isolation Handle turned to TEST.

3---3

position	CONN	counterclockwise – draws
window	TEST	out the transfer switch
	ISOLATE

Figure 3–12. Isolation Handle turned to ISOLATE.