Capacitor Switching Contactors

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Frako Capacitor Switching Contactors

Advanced Technology Contactors extend both contactor and capacitor life!

Hans von Mangoldt logoFRAKO Capacitor Switching Contactors are specifically designed for capacitor switching to achieve reliability and long life expectancy for your capacitor system.

 FRAKO Contactors are available with or without pre-charge resistors:

Contactors with pre-charge resistors (K3-…K… type)

Contactor with Pre-charge Resistors

Contactor with Pre-charge Resistors

Modern capacitor systems use special contactors that are equipped with resistors to suppress the switching currents. The resistors are switched in series with the capacitor prior to closing of the main contacts and removed from the circuit after energization, so as not to cause additional power losses.

This feature is referred to as leading transition contact with pre-charge (or pre-insertion) resistor and offers these advantages:

  • Significant damping of inrush current
  • Suppression of voltage transients during switching
  • Protection for both capacitor and contactor
  • Extended capacitor and contactor life
  • May be used with and without series reactors
  • Increased system reliability

 

 

 

Contactors without pre-charge resistors (K3-…A… type)

contactor-without-resistor

Contactor without Pre-charge Resistors

Capacitors with series reactors (for tuning or detuning) have lower peak inrush current than systems that do not include reactors. For these applications, FRAKO offers contactors with special wear resistant contact material which enables them to switch the reactor/capacitor network without the need for pre-charge resistors. These special contactors offer several advantages for capacitor switching applications that include series connected reactors: Safe switching (ON and OFF) of reactor/capacitor steps

  • Improved voltage quality made possible through chatter-proof switching operations
  • Extended capacitor life
  • Extended contactor life (>100,000 switching operations)
  • Increased system reliability

 

Call us 1-262-618-2403, Email or visit our Contact us page for Application Engineering or Quotes for Capacitor Switching Contactors.

 

Maximum Current (continuous):

K3-..K Contactors
(with resistors)
K3-18NK K3-24K K3-32K K3-50K K3-62K K3-74K K3-90K K3-115K
Amps in 50°C ambient 0-18 14-28 14-36 30-48 30-72 30-108 50-115 50-144
Amps in 60°C ambient 0-18 14-28 14-36 30-48 30-72 30-87 50-108 50-130
K3-..A Contactors
(w/o resistors)
K3-18ND K3-24A K3-32A K3-50A K3-62A K3-74A K3-90A K3-115A
Amps in 50°C ambient 18 28 36 48 32 108 115 144
Amps in 60°C ambient 18 28 36 48 72 87 108 130

General Specification:

Parameter K3-18 K3-24 K3-32 K3-50 K3-62 K3-74 K3-90 K3-115
Maximum Voltage 600 V 600 V 600 V 600 V 600 V 600 V 600 V 600 V
Switching Time (msec) 8-16 10-25 10-25 12-28 12-28 12-28 20-35 20-35
Typical RK5 Fuse (A) 50 90 125 200 250 300 300 300
Typical T Fuse (A) 70 110 150 175 175 175 300 300
Power Loss  (Watts) 3.5 W 4.7 W 5.3 W 9.2 W 10.9 W 12.5 W 9.3 W 11.0 W
Terminal capacity Flexible (awg) 2x(18-10) 1x(14-4) 1x(14-4) 1x  (10-0) 1x (18-3/0)  plus1x (8-4/0)
Terminal capacity Solid (awg) 2x(18-10) 1x(16-10) 1x(16-10) 1x(12-10) 1x(12-10) 1x(12-10) Use flexible wires
Coil Voltage range 85% to 110% of rated coil voltage
Coil Terminals Flexible (awg) 18-12 18-12 18-12 18-12 18-12 18-12 18-12 18-12
Coil Terminals Solid (awg) 14-12 14-12 14-12 14-12 14-12 14-12 14-12 14-12
Weight (kg) 0.34 0.62 0.62 1.0 1.0 1.0 2.3 2.3
UL Approval File # E 41502  for USA and Canada (UL-508)