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IB140015EN
Instructional Booklet
Page
28
Effective: August 2014
ATC-900 Magnum Tranfer Switch O & M Manual
Figure 37. Magnum Bypass Lights.
The right door control panel has following standard features:
1. BLUE light to indicate if the Source 1 switching device is iso-
lated (only if the Source 1 switching device is racked out).
2. BLUE light to indicate if the Source 2 switching device is iso-
lated (only if the Source 2 switching device is racked out).
3. RED light to indicate if the Source 1 bypass switching device
is closed.
4. RED light to indicate if the Source 2 bypass switching device
is closed.
7.2 Automatic Operation
The intelligence/supervisory circuits on Eaton transfer switches
constantly monitor the condition of both the Source 1 and Source
2 power sources. These circuits automatically initiate an immedi-
ate transfer of power from the Source 1 to the Source 2 power
source when the power source fails or the voltage level drops
below a preset value. Transfer back to the Source 1 power
source is automatic upon return of the Source 1 power source.
Monitoring the power source is always performed on the line side
of the power source to which the switch is connected. The
Source 1 power source is the preferred source and the transfer
switch will always seek this source when it is available.
7.3 Bypassing the Transfer Switch
For a Bypass type switch, there are instructions on the front of
the door and will be changed depending on the options,
7.3.1 Source 1 to Source 1 Bypass
The Source 1 switching device can be bypassed and isolated by
the following sequence (Figures 36, 37, 38, and 39):
1. Move the generator selector switch to the OFF position to
avoid nuisance starts.
2. Close the Source 1 bypass switch manually. The Source 1
bypass RED light will illuminate.
3. Remove J7 Plug from ATC-900 controller. The switch may
contain a Maintenance switch (9B) or a Test switch (6H) and
in these cases removal of the J7 power connector is not nec-
essary. Instructions are provided on the door.
4. Open and rack out the Source 1 switching device (see Section
6). The Source 1 isolated BLUE light will illuminate and the
Source 1 position energized GREEN LED on the ATC-900 con-
troller will no longer be illuminated.
5. Inspect and/or perform the needed maintenance on the Source
1 switching device.
6. Rack in the Source 1 switching device (see Section 6). The
Source 1 switching device will automatically recharge when it
is in the CONNECT position.
7. Reconnect J7 plug back onto the ATC-900 controller.
8. ATC-900 controller will automatically sense the availability of
the preferred Source 1 and will connect the Source 1 switch-
ing device. Source 1 isolated BLUE light will no longer be illu-
minated and the Source 1 position energized GREEN LED will
be illuminated.
9. Open the Source 1 bypass switch. The Source 1 bypass RED
light will no longer be illuminated.
10. Move the generator selector switch to the AUTO position
11. The Source 1 switching device is now back in automatic oper-
ation.
7.3.2 Source 2 to Source 2 Bypass
The Source 2 switching device can be bypassed and isolated by
the following sequence (considering Source 2 is the only source
available):
1. Move the generator selector switch to the RUN position to
avoid losing power to source 2.
2. Close the Source 2 bypass switch manually. The Source 2
bypass RED light will illuminate.
3. Remove J7 Plug from ATC-900 controller. The switch may
contain a Maintenance switch (9B) or a Test switch (6H) and
in these cases removal of the J7 power connector is not nec-
essary. Instructions are provided on the door.
4. Open and rack out the Source 2 switching device
(see Section 6). The Source 2 isolated BLUE light will illumi-
nate and the Source 2 position energized RED LED on the
ACT-900 controller will no longer be illuminated.
5. Inspect and/or perform the needed maintenance on the Source
2 switching device.
6. Rack in the Source 2 switching device (see Section 6). The
Source 2 switching device will automatically recharge when in
the CONNECT position.
7. Reconnect J7 plug back onto the ATC-900 controller.
8. ATC-900 controller will automatically sense the availability of
the Source 2 and will connect the Source 2 switching device.
Source 2 isolated BLUE light will no longer be illuminated and
the Source 2 position energized RED LED will be illuminated.
WARNING
THE CLOSED TRANSITION PRODUCT CONTAINS A SPECIAL CON-
TACT ARRANGEMENT (OVERLAPPING CONTACTS). MISUSE CAN
RESULT IN DEATH, SEVERE PERSONAL INJURY, AND/OR PROPERTY
DAMAGE.
