Section 5: Operation; General; Automatic Transfer Switch; Pumping Handle Charges Stored Energy Mechanism - Eaton Cutler-Hammer O & M Manual

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SECTION 5: OPERATION

5.1 GENERAL

!
THE CLOSED TRANSITION PRODUCT CONTAINS A
SPECIAL CONTACT ARRANGEMENT (OVERLAP-
PING CONTACTS). MISUSE CAN RESULT IN DEATH,
SEVERE PERSONAL INJURY AND/OR PROPERTY
DAMAGE.
A transfer switch provides main contacts to connect and
disconnect the load to and from the normal and emer-
gency power sources (Paragraph 3.2.1). A stored-energy
type transfer mechanism provides the mechanical motion
required to open and close the main contacts (Paragraph
3.2.5 and Figure 3-2).
Each switch can be manually operated. Before a switch-
ing device can be closed, the stored energy mechanism
must be charged by pumping the handle (Figure 5-1).
A single switching device for closed transition only
can be manually closed by following the instructions
detailed in Figure 5-3. An indicator window shows
whether the switch is open or closed.
Figure 5-1 Pumping Handle Charges Stored Energy
Mechanism (closed transition shown)
WARNING
Each switch in the open transition configuration
can be manually operated. Before a switching device
can be closed, the stored energy mechanism must be
charged by pumping the handle (Figure 5-1). The
switching device can be closed by pushing the close
button (Figure 5-2). The other switching device is pre-
vented from closing through a rigid mechanical interlock
(Paragraph 3.2.2). An indicator window shows whether
the switch is open or closed.
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 recom-
mended that the transfer control circuit first be iso-
lated. This is accomplished by disconnecting the
logic from the power panel. If, however, a transfer
switch is supplied with a four-position selector
switch (Option 6H), it can be turned to the off posi-
tion, making it unnecessary to unplug the logic. In
the case of the automatic transfer switch design,
any attempt to operate the manual handle without
first isolating the control circuit causes an automat-
ic transfer.

5.2 AUTOMATIC TRANSFER SWITCH

The operating sequence of an automatic transfer switch
is dictated by the switch's standard features and select-
ed options. Operation of an automatic transfer switch
during normal power source failure, normal power
source restoration and performing tests is described in
the associated Controller Instruction Booklet.
Figure 5-2 Close Switch by Pushing Close Button
(open transition shown)
IB01602002E
Effective 10/02