Bypassing & isolating – Emerson 7ADTB User Manual

Page 16

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BYPASSING & ISOLATING

(continued)

3---7

RETURN TO SERVICE continued*

This procedure explains how to return the Bypass Switch

Handle to the OPEN position. The Bypass Handle must

be in the CLOSED position (yellow indicator on NOR-

MAL or EMERGENCY) and the Isolation Handle must

be in the CONN position (window). See Figures 3–20,

3–21, and 3–22.

You can only bypass to the same source

that the ATS is connected. Solenoid

interlock prevents incorrect operation.

1

Observe which Bypass Switch Position indicator is
yellow (NORMAL or EMERGENCY) at the Bypass
Switch Handle. This indicates the source connected
to the load.

2

Un–Bypass to same source as the Bypass Switch
Position as follows (select Normal or Emergency).

Window indicator

shows green

when the ATS is

not bypassed.

Window indicator

shows yellow

when ATS is

bypassed to

Emergency.

Window indicator

shows yellow

when ATS is

bypassed to

Normal.

Figure 3–20. Bypass Handle and position indicators.

To Un–Bypass Normal Source*

To Un–Bypass Emergency Source*

(Load connected to Normal Source)

The Transfer Switch Connected To Normal light is on

and Transfer Switch Connected To Emergency light is off.

(Load connected to Emergency Source)

The Transfer Switch Connected To Emergency light is on

and Transfer Switch Connected To Normal light is off.

Turn the handle clockwise.*

Turn the handle counterclockwise.*

Turn* the Bypass Handle clockwise until the Bypass

Switch Position shows OPEN (green window indicator).

The Bypassed to Normal light should go off and the Not

In Automatic light should go off.

E

L

N

Turn

Bypass

Handle

clockwise.

ATS

Bypass Switch

Figure 3–21. Un–Bypass Normal diagram.

Turn* the Bypass Handle counterclockwise until the

Bypass Switch Position shows OPEN (green window

indicator). The Bypassed to Emergency light should go off

and the Not In Automatic light should go off.

E

L

N

ATS

Bypass Switch

Turn

Bypass

Handle

counter-

clockwise.

Figure 3–22. Un–Bypass Emergency diagram.

The Automatic Transfer & Bypass–Isolation Switch should be left in this position.

* NOTE

: When Accessory 40*B (reversed Normal & Emergency connections) is specified,

the handle push–pull operation is reversed. Follow instructions on the door.

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