CT power contactors – Revolution in handling DC and AC electric arcs

Single and double pole NO contactors for AC and DC (bidirectional). Rated insulation voltage up to 4,800 volts; conventional thermal current up to 1,100 amps.

CT1115/04 Single pole NO contactors for AC and DC (bidirectional). Ui = 1,500 V, Ith = 400 A.
CT1230/11 Single pole make contact contactors for AC and DC (bidirectional). Ui = 3,000 V, Ith = 1,100 A. Heat sink on both main connections.
CT1215/04 Double pole NO contactor for AC and DC (bidirectional). Ui = 1,500 V, Ith = 400 A.
CT1215/04 Double pole NO contactor for AC and DC (bidirectional). Ui = 3,000 V, Ith = 1,100 A. Heat sink on both main connections.

The outstanding feature of the CT range is the unprecedented combination of electromagnetic and permanent-magnetic blowout in one device. In contrast with power contactors with only electromagnetic blowout, the electric arcs are ignited in strong permanent-magnetic blowout fields at the moment of shutdown.

The dwelling times of the electric arcs in the contact zones are thus kept to an absolute minimum. This leads to a significant reduction in shutdown combustion residue. This less wear on the contact surfaces allows for extended maintenance intervals.

The CT concept can be flexibly adjusted to the requirements of customers; e.g. the number of poles, auxiliary contact design or connection technology. The product family of the single and two-pole CT contactors covers a large number of different designs for a wide number of areas of application.


Regardless of the direction of the current

Thanks to the mirror-image design the CT contactor functions regardless of the direction of the current. Unidirectional or bidirectional direct current or alternating current can be switched with the same device.

Low-wear, compact design

The arcs dwell for an extremely short time in the contact zones because they are already ignited in a powerful permanent magnetic field. Burn-up on the contacts is thus kept to a minimum.

The arc itself activates the electromagnetic fields that blow it into the arc chute. Thus the coils only need to feed high current for a minimal amount of time and can therefore be relatively lightly constructed. No additional mechanical or electrical elements are required (advanced contacts, wires, etc.). Thus wear-sensitive components can be omitted and the design remains relatively straightforward and compact.

No critical current range

The CT range also shows its strengths in the reliable shutdown of smaller currents at higher voltages. With smaller currents, the magnetic field of the electromagnets does not suffice. By using permanent magnets, the electric arc is pushed into the electric arc chamber regardless and extinguished. The critical current range typical for purely electromagnetic blowout concepts is not available in the CT.

Power switches in rail and industry

CT contactors are used in various railway networks around the world. However, they are also valued as safety power switches in industry:

  • Test benches for high-voltage systems of electric vehicles (main contactor)
  • Energy store: disconnection of the intermediate circuit (two-pole CT)

Variants with UL approval

Do you need a CT contactor with UL approval? The variants listed below already have UL approval. In addition, it is generally possible to have every CT contactor UL approved. Please contact us!

CT1115/10 N 24ECM-00
CT1115/10 N 24ECM-02
CT1115/10 N 110ECM-00
Single pole CT contactor: Un 1,500 V, Ith 1,000 A
Coil voltage: 24 V or 110 V
Aux. switch: 00: 2x S870+2x S826, 02: 4x S826
CT1215/10 N 24ECM-00
CT1215/10 N 110ECM-00
Single pole CT contactor: Un 1,500 V, Ith 1,000 A
Coil voltage: 24 V or 110 V
Aux. switch: 00: 2x S870+2x S826
CU1215/10 N 48DCM-00
CU1215/10 N 110DCM-00
Double pole CU contactor: Un 1,500 V, Ith 1,000 A
Coil voltage: 48 V or 110 V
Aux. switch: 00: 2x S870+2x S826
  • The UL versions are special versions of the 1,100 A variants without heat sink on the fixed contacts. For this reason, the above-mentioned contactors are approved for a continuous thermal current of 1,000 A max. at an ambient temperature of 70° C max.
  • CU contactors are unidirectional variants of the CT series and specially designed for use in PV systems.


Type of voltageDC (bidirectional), AC (f < 60 Hz)
Main contacts, configuration1 x SPST-NO or 2 x SPST-NO
Nominal voltage Un1,500 V or 3,000 V
Rated operating voltage Ue1,800 V or 3,600 V
Rated insulation voltage UNm3,000 V or 4,800 V
Rated impulse withstand voltage UNi15 kV or 30 kV
Pollution degree
Overvoltage category
PD3 / OV3
Conv. thermal current Ith400A, 800A oder 1,100A
Component categoryA2
Rated short-time withstand current Icwseries-specific, see catalogue
Contact material main contactsAgSnO2
Aux. contact1x S870 (a1), 1x S870 (b0), 2x S826 or 4x S826
Coil voltage Us24, 36, 72, 110 V DC
Coil tolerance-30% ... +25%
Coil power consumptionseries-specific, see catalogue
Coil suppressionSuppressor diode / double coil controller (DCC)
Mechanical enduranceseries-specific: 300.000 min. / 2.000.000 max. operating cycles
Vibration / Shock (IEC 61373)Category 1, class B
Mounting orientationhorizontal / vertical
IP rating (IEC 60529)IP00
Temperature range-40 °C ... +70 °C
Storage temperature-40 °C ... +85 °C
Weightseries-specific, see catalogue
Show all data

Related Downloads

Catalogue C20
CT contactors - 1 pole power contactors up to 3 kV for AC and DC
Catalogue C21
CT contactors - 2 pole power contactors up to 3 kV for AC and DC
Manual C20-C21-M
Contactors CT — 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

Samples can be ordered here


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