General Description; Construction - Toshiba JK 720 Instruction Manual

Basic Installation and Operation Guide JK Series 720 Controllers

GENERAL DESCRIPTION

Toshiba JK 720 ampere medium voltage controllers are AC
general-purpose NEMA Class E2 controllers designed for
applications at utilization voltages ranging from 2.3 through 6.6
kV. They are normally used to control motor loads, although other
types of loads such as variable frequency drives (VFDs),
transformers and capacitors are possible.

Construction

The standard enclosure size for the 720 ampere controller is 36"
wide by 36" deep by 90" high. One controller is supplied per
vertical section. Each section is divided into two isolated
compartments, each with a separate door. The lower
compartment contains medium voltage controller components
(>600V) while the upper compartment contains low voltage
components (<600V) (Fig. 21).
Main horizontal bus is provided when required to supply power to
a line-up of controllers. The main bus is located at the rear of
the enclosure midway between the top and bottom. A common Fig. 21 Standard Controller Arrangement
ground bus is also provided for multiple sections.
The medium voltage compartment (Fig. 22) consists of:
1) Fix-mounted non-load break isolation switch
2) Fix-mounted vacuum contactor
3) Fix-mounted current-limiting power fuses
4) Current transformers for metering
5) Control power transformer and optional potential
transformer
6) Load cable terminations
Fig. 22 Controller Compartment
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