Kohler KGS - Operation of Bypass;Isolation Switch

TP-6836 4/1448 Section 7 Bypass/Isolation
7.3 Operation of Bypass/Isolation
Switch
An automatic transfer switch equipped with a
bypass/isolation switch allows withdrawal of the ATS for
testing and/or service without interrupting power to the
load.
Normally the bypass switch is open and the ATS feeds
the load. See Figure 7-2. Closing the bypass switch
allows withdrawal of the ATS to the TEST or ISOLATE
positions. Mechanical and electrical interlocks prevent
cross-servicing or bypassing to an unacceptable
source.
ATS
Bypass emergency
source
Bypass
Bypass in the OPEN position and
ATS in the normal position
Bypass normal
source
Emergency
source
Normal
source
Load
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Figure 7-2 Automatic Position
In the TEST position, the ATS is disconnected from the
load but the controller is powered to allow testing. See
Figure 7-3.
ATS
Bypass emergency
source
Bypass
Bypass in the normal position and ATS in the
TEST position (ATS load connection is open)
Bypass normal
source
Emergency
source
Normal
source
Load
567328
Figure 7-3 Test Position
In the ISOLATE position, the ATS is completely
withdrawn and can be removed from the enclosure for
maintenance or service. See Figure 7-4.
ATS
Bypass emergency
source
Bypass
Bypass in the normal position and ATS
in the ISOLATE position
Bypass normal
source
Emergency
source
Normal
source
Load
567328
Figure 7-4 Isolate Position
If the normal source fails while the ATS is bypassed, an
auxiliary contact on the bypass s witch starts the
generator set. Use the manual handle to transfer the
load to the available source. Interlocks prevent transfer
if the ATS is in the circuit and connected to the opposite
source.
Interlocks prevent reconnection of the ATS after bypass
if the ATS and bypass switch source positions do not
match. See Figure 7-5.
ATS
Bypass emergency
source
Bypass
Bypass in the normal position and
ATS in the normal position
Bypass normal
source
Emergency
source
Normal
source
Load
567327
Figure 7-5 Bypass Position