C300 – Single-pole bi-directional DC contactors up to 1,500 volts

Compact single-pole NO contactors for AC and DC up to 1,500 volts rated insulation voltage.

C300-500 Single-pole bi-directional DC Ui up to 1,500 volts
Ith up to 500 amps, version with integreated PWM module

The bi-directional DC contactors C300 switch high power in the smallest space. With a making capacity of up to 4,500 amperes, the extremely compact series is suitable for applications with high inrush currents or high capacitances.
All versions can carry up to 500 amperes continuously In the event of a short circuit, even 6,000 amperes may flow for 20 milliseconds without the contacts welding.
This means that the contactor retains its full function to separate large powers when required: up to 500 amperes and up to 1,500 volts – regardless
of the direction of the current. This full bi-directionality is important for systems with a charging and discharging process, such as in battery storage or electric vehicles. Other typical applications are the DC circuit in inverters, combiner boxes in photovoltaic systems or the management of battery storage systems.


Compact dimensions – high rated insulation voltage Ui up to 1,500 volts

Smallest dimensions – great performance! Nevertheless, all the air gaps in the contact area have been generously dimensioned. The rated insulation voltage is 1,500 volts. The arc chamber of the C300 is made of plastic. This is efficient and saves weight.

High thermal continuous current Ith of up to 500 amps

All versions of the C300 can permanently carry up to 500 amps – provided a sufficiently dimensioned connection cross-section of 300 mm². The maximum ambient temperature for industrial applications is 85 °C. These excellent values are achieved through very high contact forces.

Making capacity Icm up to 4,500 amps

The C300 can switch on a current of up to 4,500 amps.
High contact forces and burn-off resistant silver contacts favour the excellent breaking capacity.
An integrated PWM controller regulates the coil current for all operating states, ensures low-bounce switching on and optimises the holding power.

Short-time current-carrying capacity Icw up to 6,000 amps

For 20 milliseconds, the C300 can carry a current of up to 6,000 amps without the contacts welding. This time is sufficient for the short-circuit protection to trip. The short-time current carrying capacity is supported by high contact forces and an optimised contact geometry.

Full bidirectionality – reliable disconnection of high performances

All versions of the C300 can reliably separate high currents and voltages when required, regardless of the direction of the current. These properties are achieved by the special arrangement of blowout magnets and arc chamber, burn-off resistant silver contacts, high contact forces and generously dimensioned air gaps in the contact area.

Auxiliary switch with mirror contact function

The C300 contactors have an integrated auxiliary contact with mirror contact function according to IEC 60947-4-1, annex F.
Mirror contacts are required in feedback circuits of safety controls. The mirror contact function informs about the switching state and ensures that the NC contact of the auxiliary contact is not closed at the same time as the NO main contact.


  • DC fast charging stations
  • Battery test benches for the automotive industry
  • Battery management for zero-emission propulsion systems in maritime applications and DC charging on and off-shore
Stationary applications
  • Grid stabilization and battery energy storage
  • Regenerative systems in industrial plants
  • Battery management systems
  • Photovoltaics and UPS


Type of voltageDC bi-directional
Main contacts, configuration1 NO
Rated operating voltage Ue1,000 V
Rated insulation voltage Ui1,000 V @ PD3
1,500 V @ PD2
Rated impulse withstand voltage Uimp8 kV
Pollution degree
Overvoltage category
PD2 / PD3
Conv. thermal current Ith500 A @ 300 mm2, 70° C
Rated short-time withstand current Icw6,000 A @ t = 20  ms
< 25,000 A @ t < 20  ms (contact welding, no explosion, no fire)
Rated short-circuit making capacity Icm4,500 A @ L < 50 µH
Auxiliary switches1 NC with mirror contact function
Coil voltage Us12 ... 24 V DC
(operating range 10.5 ... 36 V DC)
PWM module, integrated
Mounting orientationhorizontal, vertical
Temperature range-40° C ... +85° C
Mechanical endurance200,000 operations
Show all data

Related Downloads

Catalogue C300
C300 contactors – 1 pole bi-directional DC NO contactors up to 500 amps
Manual C300-M
Contactors C300 — Installation and Maintenance Instructions
Safety instructions contactors
AFS / C100 / C110B / C130 / C137 / C152...C159 / C160 / C162 / C163 / C164 / C165 / C193 / C195 / C294 / C295 / C160 / C3xx / C8xx / C400 / C600 / CA / CF / CH / CL / CP / CPP / CS / CT / CU / S100/80 / S132 / S134 / S135 / S005 / S007 / S008 / S306 / S307 / S310
/en/products/contactors/thank-you/C300 – DC bi-directional switchingContactors

Your quick contact to us!

If you have any questions, suggestions or other concerns, please let us know. Please fill out our short contact form.