Current Limiting Reactor, 160 Continuous Amps, 480 VAC L-L,

35000 Available Amps, 4700 Fault Limit Amps, P/N KK-24

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

The inductance calculations are shown below:

  • L-L = 480 VAC
  • V L-N = 277 VAC
  • Available Fault Current = 35000 Amps
  • Designed Fault Current = 4700 Amps
  • Z system (based on Available Current) = 277 / 35000 = 0.00791 Ohms
  • Z system (based on Designed Fault Current) = 277 / 4700 = 0.05894 Ohms
  • Z needed = Square Root of (0.05894² – 0.00791²) = 0.0584 Ohms
  • Inductance = 0.0584 / (2 x 3.142 x 60) = 155 uH
  • Voltage Drop = 0.0584 x 160 = 9.344 V
  • Percentage Voltage Drop = 9.344 / 480 = 1.95 %

Specifications:

A. CLR, 160 Amps continuous, 35000 available Amps, 4700 Amps desired fault current, P/N KK-24
B. Copper windings
C. Approvals: none
D. System shipping weight: 400 lbs. (one enclosure)
E. Calculated Inductance Value: 155 uH, 160 Amps continuous
F. Three inductors in one enclosure (50″H x 46″W x 36″D)

 

The detail of one Air Core Inductor, KK-24-1 is shown below. Three KK-24-1 are required for one CLR KK-24.

 

 

 KK-24-1. Three are required per system

 

Specifications:

  • Air Core Inductor, P/N KK-24-1
  • L (1, 2) = 155 uH
  • Continuous Current: 160 Amps
  • Frequency: 60 Hz
  • Copper windings
  • Approvals: None
  • Copper bus bars are 1″ x 1/4″ thick with one hole
  • One CLR consists of three separate air core inductors in one indoor enclosure

Three KK-24-1 are housed inside an indoor enclosure as shown below:

 

 

The System consists of three inductors in one indoor enclosure. Indoor Enclosure Dimensions are 50″H x 46″W x 36″D

Three Inductors in one indoor enclosure

All our CLR’s 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.