IB01602007E
For more information visit: www.cutler-hammer.eaton.com
Instruction Bulletin
Effective: June 2003
Page
5
O&M Manual for
Non-Automatic Transfer
Switches (30 – 1200 Amperes)
Non-Automatic Transfer Switch (Manually Operated)
Non-automatic transfer switches provide the main contacts
and the transfer mechanism to effect the transfer of the main
contacts from source to source. Transfer of power, however,
is accomplished by true hand operation (not power assisted)
of the transfer switch. This switch is similar to the basic
switch in that an intelligence circuit and a motor driven
mechanism are not part of the design.
Non-Automatic Transfer Switch (Electrically Operated)
This transfer switch is similar to the non-automatic transfer
switch (manually operated) except that an electrical opera-
tion feature is added. The switch electrically transfers power
when an appropriate position is chosen on the selector
switch that is mounted on the front of the enclosure.
If necessary, the switch can also be operated manually.
1.2.2 Design Configuration
The Cutler-Hammer Transfer Switch is a rugged, compact
design utilizing molded case switches to effect the transfer
of essential loads from one power source to another
(
Figures 3
,
4
and
5
). Molded case switches are interlocked
to prevent both switches from being closed at the same
time. The versatile design, in addition to standard transfer
functions, offers an optional integral thermal and short
circuit protection in either or both switching devices.
Molded case switches and the associated transfer mecha-
nism are usually mounted vertically in the assembly. The
vertical configuration (225 – 1200 amperes) is accomplished
by utilizing a positive, metallic transfer and interlocking
system between the molded case switches. A horizontally
mounted transfer mechanism is utilized with transfer
switches 30 – 150 amperes.
The Cutler-Hammer Transfer Switch was designed with
installation ease and simplified maintenance in mind. Three
main panels comprise the automatic transfer switch design:
■
Power Panel
■
Voltage Selection Panel
■
Logic Panel
Each panel is independently mounted with interconnecting
wiring terminated in connector plugs to permit individual
door or panel removal without disturbing critical connec-
tions. Enclosure mounting is simplified by utilizing top and
bottom mounting flanges with elongated mounting holes.
For the vertical design, installed power panel positioning
bolts, elongated mounting holes and pre-tapped inserts
insure proper power panel mounting after initial enclosure
installation or when switching from top to bottom entry
and vice versa. Refer to
Section 4
for mounting and
modification details.
1.3 Transfer Switch Catalog Number Identification
Transfer switch equipment catalog numbers provide a signifi-
cant amount of relevant information that pertains to a particu-
lar piece of equipment. The Catalog Number Identification
Table (
Table 1
) provides the required interpretation informa-
tion. An example is offered to initially simplify the process.
Example:
Catalog Number (circled numbers correspond to
position headings in
Table 1
)
The catalog number
NTVEKDA30300XSU
describes a
non-automatic transfer switch with the switching devices
mounted vertically in the enclosure. The intelligence repre-
sented by the control panel is electromechanical. The
Cutler-Hammer Series C
T
Type HKD is used as the switching
device and is in the form of a 3-pole molded case switch
on each source. The continuous current rating of this
equipment is 300 amperes and applicable at 480 Vac, 60 Hz.
The transfer switch equipment is enclosed in a NEMA
T
1
enclosure and is both UL
T
and CSA
T
listed.
Figure 3. Vertical Design Automatic Transfer Switch Equipment with
Deadfront Cover in Place Over Power Panel (225 – 1200 Amperes)
Figure 4. Vertical Design Automatic Transfer Switch Equipment Shown
with Deadfront Cover Removed (225 – 1200 Amperes)
NT V E KD A 3 0300 X S U
a
to
b c d e f g h i
to
l m n o
Voltage
Selection
Panel
