Emerson 7ATB manual TESTING & SERVICE continued, 1. Trouble-ShootingChecks, Manual Load Transfer

TESTING & SERVICE (continued)

TROUBLE-SHOOTING

Note any optional accessories that may be furnished on the ATB and review their operation. Refer to any separate drawings and/or instructions that may be packed with the ATB.

Hazardous voltage capable of causing shock, burns, or death is used in this switch. Do not touch the power or load terminals of the bypass switch or transfer switch!

Table 2-1. Trouble-Shooting Checks.

PROBLEM	CHECK IN NUMERICAL SEQUENCE
	1	2	3
	OPERATION	GEN-SET	VOLTAGE
Engine–generator set does	Hold Transfer Test switch 15	Starting control must be in the
not start when the Transfer	seconds or the outage must	automatic position. Batteries
Control switch is turned and	be long enough to allow for	must be charged and	–
held in Transfer Test position	Feature 1C time delay plus	connected. Check wiring to
or when normal source fails.	engine cranking and starting.	engine starting contacts.
Transfer switch does not	Wait for Feature 2B time delay	Generator output circuit	Voltmeter should read at least
transfer the load to the	to time out.	breaker must be closed.	90% of nominal phase to
emergency source after the		Generator frequency must be	phase voltage between
engine–generator set starts.		at least 95% of nominal (57 Hz	transfer switch terminals EA &
		for a 60 Hz system.) *	EC (or EL1 & EL2 for 2 pole)*
Transfer switch does not	Wait for Feature 3A time delay		Voltmeter should read at least
transfer the load to normal	to time out.		90% of nominal phase to
source when normal returns		–	phase voltage between
or when the Transfer Control			transfer switch terminals NB &
switch is released.			NC, NC & NA, & NA & NB (or
			NL1 & NL2 for 2 pole).
Engine–generator-set does	Wait for Feature 2E time delay	Starting control must be in the
not stop after load retransfer	to time out.	automatic position.	–
to the normal source.

*These are factory settings. Refer to Controller’s User’s Guide.

If the problem is isolated to circuits on the controller or the transfer switch, call your local ASCO Power Technolo- gies sales office or ASI: in the United States, call 1–800–800–2726. Furnish the Serial No., Catalog No., and Bill of Material (BOM) No. from the transfer switch nameplate.

MANUAL LOAD TRANSFER MAINTENANCE HANDLE

This procedure manually transfers load to other source if the Transfer Switch or Controller are out of service.

Close enclosure doors to prevent personal injury in case of electrical system fault.

1.Be sure that the Bypass Handle is CLOSED on either Emergency or Normal (see page 3–1).

2.Be sure that the Isolation Handle is in the TEST or ISOLATE position (see page 3–2).

3.Turn the Bypass Handle counterclockwise to OPEN the Bypass Switch. Then Bypass to the other source (see page 3–1).

Bypass and isolate the Transfer Switch before using the maintenance handle! See pages 3–1 and 3–2. Remove the maintenance handle after using it and store it on the frame.

Turn counterclockwise to Emergency.

Turn clockwise	Grasp
to Normal.	handle
	firmly

slide hub	insert
onto shaft
	handle
	into hole

2---2