Emerson 7ACTB manual Bypassing & Isolating, continued, Return To Service

BYPASSING & ISOLATING

(continued)

	RETURN TO SERVICE
This procedure explains how to return the automatic		Solenoid interlock prevents you from closing
transfer switch (ATS) to service after inspection and		the isolation contacts until the ATS is in the
maintenance. Observe the Bypass Switch Position indica-		same position as the Bypass Switch.
tor and lights). Refer to Figures 3–7, 3–8, 3–9, and 3–10.		3. Observe which Bypass Switch Position indicator is
1. Slide the transfer switch (ATS) into the enclosure		black (NORMAL or EMERGENCY) at the Bypass
		Switch Handle. This indicates the source connected
(isolation contacts facing inward) until its crank pins
		to the load.
engage the latch plates on both sides. Next push in
		4. Observe which Transfer Switch Connected To light is
side rail carriage. Then close enclosure door.
		on (Normal or Emergency) on the door. This is the
		position of the Transfer Switch. If it is not in the same
Close the enclosure door to prevent personal		position as the Bypass Handle change the position of
		the Transfer Switch as follows:
injury in case of electrical system fault.
		To change the position of transfer switch
		Operate to NORMAL	OperatetoEMERGENCY
Align position indicator. Do not leave		Turn Transfer Control	Turn Transfer Control
		switch to Retransfer	switch to Transfer Test
the handle in an intermediate position.
		Delay Bypass.	(hold 15 seconds).*
	position	Connected To Normal	Connected To Emergency
		light should come on.	light should comes on.
	window
CONN		* If Feature 2B time delay is used, there will be a delay
TEST		before transfer to Emergency.
ISOLATE
		NOTE: With Normal available, the automatic
		transfer switch will not stay in the emergency
		position unless Feature 3A time delay is used
	unfold	(at least 30 seconds).
	crank
		Do not close the isolation contacts unless
		the Transfer Switch (ATS) and Bypass
clockwise – draws in the Transfer Switch		Switch are in the same position!
	Figure 3–8. Isolation Handle.	5. When the transfer switch is in the same position as
		the Bypass Switch	handle, continue turning the

2. Turn the Isolation Handle clockwise (approx. 7

turns) until the window shows TEST. The ATS can be

Isolation Handle clockwise (about 16 turns) until the window shows CONN (connected).

tested now without load interruption (see page 2–1).

Bypass Switch E

Turn crank
clockwise	L
until
window
shows
TEST.
	N

Turn crank clockwise until window shows

CONN (connected).

Bypass Switch	E
	L
	N
ATS

ATS

Figure 3–9. ISOLATE to TEST position.

Figure 3–10. TEST to CONNECTED position.

Now continue to the next page for instructions on how to return the Bypass Handle to the OPEN postition.

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