Gas-filled contactors for high voltage DC switching

Stuck Detection allows monitoring trouble-free switching. In case the contactor is stuck, the Aux COM and Aux NO wires will be short, hence the circuit is closed and the LED will be on (see example circuit). The Aux COM and Aux NC wires work the opposite way: the LED is off when the contactor is stuck. Stuck Detection is located at the opposite side, away from the arc-chamber to avoid influence from the main switching operation. Stuck Detection may also be known as state-control or auxiliary contact.

TDK design advantages

• Contactless
• No impact on breakting capability
• No impact on dielectric strength

Integrated temperature sensor to ensure safe operation. Loose cables or bus-bars lead to increased contact resistance and therewith increased heat. The integrated temperature sensor indicates increased temperatures on the spot, ensuring a safe-operation.

Integrated voltage sensor allows direct measurement of voltage-drop at the main contact.

Temperature Sensor

• Wires for the temperature sensor are connected to an NTC thermistor with a resistance of 10 kΩ (R25)
• Measurable temperature range is −55 …+155 °C
• NTC type: EPCOS B57551G1103+000 (RT No 8307). Tolerance = ±2%

Voltage Sensor

• Voltage 1 and voltage 2 wires are connected to the main terminals via 1 MΩ resistors
• Tolerance < 1%

 Single coil versus dual coil

Single Coil

• No additional current durig make (pick-up)
• Operating power: 6 W, 0.5 A @ 12 V
• No economizer required
• Integrated coil termination

Dual Coil

• Power during make (pick-up) 28 W, 3.2 A @ 12 V during 80...120 ms
• Operating power: 4.2 W (0.35 A) @ 12 V
• Hot-restartability (<1 s)
• Works like an economizer but without the disadvantages of a PWM circuit
• Integrated coil termination

Dual coil

Estimated service life for resistive loads

• High-voltage contactors are not designed to permanently switch under load
• The device switches under load only in case of an emergency
• Switching capability depends on voltage, current, inductance and resistance during break
• Dual coil for increased lifetime of >50%: 3000 cycles with 300 A @ 450 V, 1000 cycles with 300 A @ 750 V

HVC is designed bipolar, allowing connection independently of polarity. This is a great advantage during assembly and further allows charging and discharging of a battery without using a second contactor.