A current-limiting reactor is used when the prospective short-circuit current in a distribution or transmission system is calculated to exceed the interrupting rating of the associated switchgear. The inductive reactance is chosen to be low enough for an acceptable voltage drop during normal operation, but high enough to restrict a short circuit to the rating of the switchgear. The amount of protection that a current-limiting reactor offers depends upon the percentage increase in impedance that it provides for the system.

The main motive for using current-limiting reactors is to reduce short-circuit currents so that circuit breakers with lower short-circuit breaking capacity can be used. They can also be used to protect other system components from high current levels and to limit the inrush current when starting a large motor.

The customer application is shown below:

Current Limiting Reactor, Three Phase

Inductance Calculation

Specifications:

A. CLR, 1580 Amps continuous, 17500 VAC L-L, 50 Hz, P/N KK-17
B. Short-circuit withstand: 32 kA rms / 3s
C. Inductance value: 921 uH
D. Each inductor in separate enclosure (65” x 65” x 65”) or TBD
E. Each enclosure with inductor: 1500 lbs., three are required
F. Copper windings
G. Approvals: none
H. Total system weight: 4800 lbs. (one complete system with crating)

The detail of one Air Core Inductor, KK-17A is shown below. Three KK-17A are required for one CLR KK-17.

Specifications:

• Air Core Inductor, P/N KK-17-1
• L (1, 2) = 921 mH
• Continuous Current: 1580 Amps
• Frequency: 50 Hz
• Copper windings
• Approvals: None
• Copper bus bars are 4″ x 3/8″ thick with two holes
• One CLR consists of three separate air core inductors in three separate indoor enclosures

P/N KK-17 consists of three modules to offer 1580 Amps continuous. shown below is one module. Each module is capable of 500 Amps continuously.

Each KK-17-1 is housed inside an indoor enclosure (65″H x 65″W x 65″D) as shown below. Three 500 Amps modules stacked vertically to build a 1500 Amps inductor.

Notes:

1. (A), (B), (C) are 10-inch minimum

 The System consists of three inductors in three separate enclosures

All our CLRs are custom-built to order. To discuss your specific application, please call our phone number at (714) 624-4740, or send us an email at quote@lcmagnetics.com