Emerson 7ATB manual Functional Test, Voltage Checks

INSTALLATION (continued)

observe these lights

		Transfer
Transfer Switch	Transfer Switch	Control
Connected	Connected	Retransfer	Transfer
To	To	Delay	Test
Normal	Emergency	Bypass	(15HOLDSECONDSFOR )
GREEN	RED
Normal	Emergency
Source	Source
Accepted	Accepted
GREEN	RED

Figure 1-2. Standard controls and indicators.

Functional Test

Read all instructions on the Wiring Diagrams and labels affixed to the ATB. Note the control features that are provided and review their operation before proceeding.

After installing the ATB check the following:

–Bypass Handle should be in the NORMAL position.

–Isolation Handle should be in the CONN position.

–TS transfer switch Normal contacts should be CLOSED (Emergency contacts should be OPEN)

If handles are not in correct positions, follow instruc- tions for Bypassing and Isolating the automatic transfer switch in Section 3. Do not force the handles. Electrical interlocks prevent a wrong sequence of operation.

1 – Voltage Checks

First check nameplate on transfer switch; rated voltage must be the same as normal and emergency line voltages.

Close the normal source circuit breaker. The Transfer Switch

1Connected To Normal and the Normal Source Accepted lights should come on.

Use an accurate voltmeter to check phase to phase and

2 phase to neutral voltages pres- ent at the transfer switch normal source terminals.

Close the emergency source circuit breaker. (Start generator,

3if necessary.) The Transfer Switch Connected To Normal & Emergency Source Accepted lights should come on.

Use an accurate voltmeter to check phase to phase and

4 phase to neutral voltages pres- ent at the transfer switch emer- gency source terminals.*

Use a phase rotation meter to

A B C

Use extreme caution when using a meter to measure voltages. Do not touch power terminals; shock, burns, or death could result !

Perform steps 1–6 at the right. Observe the status lights. See Figure 1–2.

QBlack square means light is on. S White square means light is off.

*If necessary, adjust voltage regulator on generator per the manufacturer’s recommendations. The ATB will respond only to rated voltage specified on the nameplate.

5 check phase rotation of emer- gency source; it must be the same as the normal source.

Shut down the engine–genera- tor, if applicable. The Emergen- cy Source Accepted light should

6go off. Then put the starting control selector switch (on the generator set) in the automatic position. Close enclosure door.

Now continue to 2 – Electrical Operation on next page.

1---3