molded case circuit breakers - Eaton Canada

282
SWITCHGEAR (MEDIUM VOLTAGE) FUSIBLE
Load Interrupter Metal Enclosed Switchgear
PRODUCT DESCRIPTION
Approximately 40 years ago,
Westinghouse began to produce a threephase
load interrupter medium-voltage
switch housed in a metal enclosure. The
switch is rated 5 to 15 kV and 600 to 1200
amperes. This switch was an economical
visible disconnect used primarily for unit
substations, main service entrance and
distribution of service entrance via a lineup
of these switches. Most switches have
a fuse for circuit protection on the load
side. The switch structure consists of 11
gauge structural steel. The appearance of
the switch has not changed drastically
over the years.
PRODUCT HISTORY
Originally a Westinghouse Product
Metal enclosed load break air interrupter
switches were first produced in 1952
under the name Load Break Fusible (LBF)
at M & R facilities around the country. In
1964, the manufacturing of the product
was consolidated in the Cincinnati, OH
facility. The product was discontinued in
1972 and replaced with Westinghouse
Load Interrupter (WLI) having many
design changes and improvements. Parts
for the two products are incompatible but
the current WLI design can be added to
existing LBF lineups. The WLI product line
PRODUCT HISTORY TIMELINE
was moved to the Sumter, SC manufacturing
facility in 1979.
As stated earlier, LBF and WLl look similar
in design. They can be differentiated by
the nameplate located behind the operating
handle access door. The front is largely
covered by the main door, with viewing
window, providing access to the switch
and fuse compartment. A smaller access
door on the main door allows access to
the switch operating mechanism. Upon
opening the main door, the switch in the
Page Product 1950 1955 1960 1965 1970 1975 1980 1985 1990 Present
283 Westinghouse LBF
284
WLI + MVS
➃
➁
➂
➉
➁
➄
➅
➆
➀
➇
➈
Standard Manually Operated Fused WLI
Switch
➀ Switch Position Indicator/Operator
Mechanism
➁ Provisions for Padlocking Door
➂ Inspection Window
➃ Full Height Main Door
➄ Door Stop, Foot Operated
➅ Grounded Metal Safety Barrier
➆ Door Interlock
➇ Switch Interlock
➈ Interphase Barrier
➉ Switch Operator Mechanism Access
Door
upper part of the structure is covered by a
protective screen barrier which allows
visual inspection. The fuses, when provided,
are located in the lower part of the
structure, and are readily visible for easy
maintenance when the main door is open.
The rear of the switch structure is generally
used for cable entrance and/or exit.
Access to the cable entrance/exit area
is via a rear cover or door.
March 2001