Emerson 7ATB Manuel D’Utilisation
SECTION 3 BYPASSING & ISOLATING
3---1
BYPASSING THE ATS*
This procedure explains how to Bypass the closed
automatic transfer switch contacts. Bypassing is
required before the ATS can be tested or isolated. The
Bypass Handle must be in the OPEN position (green
indicator) and the Isolation Handle must be in the
CLOSED position (window). See Figures 3–1, 3–2, and
3–3.
You can only bypass to the same source
that the Transfer Switch is connected.
Solenoid interlock prevents incorrect operation.
1. Observe which Transfer Switch Connected To light is
on (Normal or Emergency) on the door. This is the
position of the automatic transfer switch.
position of the automatic transfer switch.
2. Bypass to the same source as connected to transfer
switch as follows (select Normal or Emergency).
To Bypass Normal push in handle
all the way & turn it clockwise.*
To Bypass Emergency pull out han-
dle all the way & turn it clockwise.*
Indicator shows:
green
O
OPEN when the
ATS is not bypassed.
Indicator shows:
yellow
O
EMERGENCY CLOSED
when ATS is bypassed to Emergency
or
yellow
O
NORMAL CLOSED when
ATS is bypassed to Normal Source.
Figure 3–1. Bypass Handle and position indicators.
To Bypass Normal Source*
(Load connected to Normal Source)
The Transfer Switch Connected To Normal light is on
and Transfer Switch Connected To Emergency light is off.
Push in* the Bypass Handle all the way, then turn it
Push in* the Bypass Handle all the way, then turn it
clockwise until Bypass Switch Position shows CLOSED
on NORMAL (yellow indicator). The red light Unit
Not In Automatic will flash.
E
L
N
Push in
Bypass
Handle
&
turn it
clockwise.
ATS
Bypass Switch
Figure 3–2. Bypass to Normal.
To Bypass Emergency Source*
(Load connected to Emergency Source)
The Transfer Switch Connected To Emergency light is on
and Transfer Switch Connected To Normal light is off.
Pull out* the Bypass Handle all the way, then turn it
clockwise until Bypass Switch Position shows CLOSED
on EMERGENCY (yellow indicator). The red light
Unit Not In Automatic will flash.
E
L
N
ATS
Bypass Switch
Pull out
Bypass
Handle
&
turn it
clockwise.
Figure 3–3. Bypass to Emergency.
The automatic transfer switch can now be put in the TEST or OPEN position. See ISOLATING on page 3–2.
* NOTE
: When Accessory 66A (reversed Normal & Emergency connections) is specified,
the handle push–pull operation is reversed. Follow instructions on the door.