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IB140015EN
Instructional Booklet
Page
22
Effective: August 2014
ATC-900 Magnum Tranfer Switch O & M Manual
Section 5: Operation
5.1 General
A transfer switch provides main contacts to connect and discon-
nect the load to and from the Source 1 and Source 2 power
sources. A stored-energy type transfer mechanism provides the
mechanical motion required to open and close the main contacts
(Paragraph 3.2.1).
Each switch can be manually operated. Before a switching device
can be closed, the stored energy mechanism must be charged by
pumping the handle (Figure 24).
Figure 24. Pumping Handle Charges Stored Energy Mechanism
(Closed Transition Shown).
In the
closed transition product
, a single switching device can be
manually closed by following the instructions detailed in Figure
26. An indicator window shows whether the switch is open or
closed.
The open transition switching device can be closed by pushing the
close button (Figure 25). The other switching device is prevented
from closing through a rigid mechanical interlock (Paragraph
3.2.2). An indicator window shows whether the switch is open
or closed.
Figure 25. Close Switch by Pushing Close Button.
5.2 Automatic Transfer Switch
The operating sequence of an ATS is dictated by the switch’s
standard features and selected options. Operation of an ATS dur-
ing Source 1 power source failure, Source 1 power source restora-
tion, and testing is described in the associated Controller
Instruction Booklet.
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.
NOTICE
IF A TRANSFER SWITCH WITH ANY TYPE OF ELECTRICAL OPERAT-
ING CAPABILITIES IS TO BE OPERATED MANUALLY UTILIZING THE
MANUAL OPERATING HANDLE, IT IS STRONGLY RECOMMENDED
THAT THE TRANSFER CONTROL CIRCUIT FIRST BE ISOLATED. THIS
IS ACCOMPLISHED BY DISCONNECTING THE S7/P7 PLUG ON THE
TRANSFORMER PANEL. AN AUTOMATIC ENGINE START WILL
OCCUR UNLESS THE GENERATOR RUN SWITCH SET TO “OFF.” I
F
,
HOWEVER, A TRANSFER SWITCH IS SUPPLIED WITH A FOUR-POSI-
TION SELECTOR SWITCH (OPTION 6H), IT CAN BE TURNED TO THE
OFF POSITION, MAKING IT UNNECESSARY TO UNPLUG THE LOGIC.
IN THE CASE OF THE ATS DESIGN, ANY ATTEMPT TO OPERATE
THE MANUAL HANDLE WITHOUT FIRST ISOLATING THE CONTROL
CIRCUIT CAUSES AN AUTOMATIC TRANSFER.
