Specifications

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Another category of large circuit breakers is the low voltage
(LV) power circuit breaker. LV power circuit breakers are
generally drawout mounted and may be used in switchboards
or switchgear. LV power circuit breakers intended for use in
the United States conform to IEEE standards (C37.13, C37.16,
C37.17, and C37.50). The corresponding UL specification for LV
power circuit breakers is UL 1066.
Siemens WL modular family of circuit breakers includes both
ICCBs that conform to the UL 489 specification and LV power
circuit breakers that conform to UL 1066 and corresponding IEEE
specifications.
Frame Size I Frame Size II Frame Size III
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I
O
I
O
I
WL UL 489 circuit breakers have a rated maximum operating
voltage of 600 V and are available in three frame sizes with
frame ratings from 800 to 5000 amps. All three frame sizes have
fixed-mounted and drawout-mounted versions.
WL UL 1066 circuit breakers are generally used in low voltage
(LV) switchgear as drawout-mounted breakers, have a rated
maximum operating voltage of 635 V, and are available in two
frame sizes with frame ratings from 800 to 5000 amps.
Vacu-Break Fusible Switches A fusible disconnect switch is another type of device used
in panelboards and switchboards to provide overcurrent
protection. Properly sized fuses, located in the switch, open
when an overcurrent condition occurs. Siemens Vacu-Break
fusible switches are available with continuous current ratings
up to 1200 amps.