Hybrid Arc-less Contactor [UHA]

Hybrid Arc-less Contactor

  • Series:[UHA] 40-250A, 220-1350VAC
  • Standard:IEC 60947-1 class AC-3 and AC-4


UHA Series Hybrid Arc-less Contactor is the latest generation of electro-magnetic contactors. UHA has a built-in electronic detecting and controlling circuit with a by-pass Thyristor to form an extremely fast action that detects main-contacts opening movement then by-pass the circuit to the Thyristor within 10 milliseconds. The magic is at 100% accuracy! UHA can always by-pass the main-contacts at exact zero-degree-current-wave. But how? Speed is the key, detecting speed plus response time is much less than 1 cycle [66.7ms].

For ten of years, electrical maintenance engineers suffer many trouble shooting problem from traditional Electro-Magnetic Contactors due to noise, contacts deterioration, contacts welded and electrical coil burn out without any better solution. Now UHA brings the great solution to solve all these problems at a time. Required no any maintenance-check until 200,000 times operation. With UHA - you save energy, time and materials. You are a Green Energy user and executer.


UHA contactor meets IEC Standard 60947-1 class AC-3 and AC-4 requirements, rated continuous current from 40A, 60A, 80A, 100A, 125A, 160A, 200A and maximum 250A. Best application of UHA is to replace traditional electro-magnetic contactors which create noise, contacts welded, shorter service life; and to replace silicon-switches which have over-heating risk, create harmonics and non-predicable burn-out.


  • Design to continuous service for 100,000 hours.
  • Exact zero-degree by-pass arcing circuit.
  • Mechanical bridge contacts, higher current ratings.
  • Compact in size.
  • Good for explosion-proof application.
  • 3 phases synchronous operation, no unbalanced phasing risk.
  • Low contacts resistance, save energy consumption.
  • Low power DC-coil, no burn-out risk.

Theory of Operation

Thyristor by-pass the main-contact precisely at zero-degree-current-wave in a few millisecond upon opening-signed received. Precisely detect both voltage and current difference is the key to get 100% accuracy of by-pass action.

UHA Installation Instruction

  • Environmental temperature range shall be: -40°C ~ +45°C
  • Relative humidity shall be: less than 95%
  • Pollution class: 3
  • Installation class: 3 (III)
  • Mounting surface angle: maximum ±5° incline.
  • Mounting place sea level: < 2000M
  • Mounting surface shall be free from: vibrating, moving, impacting.
  • Main circuit is not designed for DC power interrupting.
  • Application for paralleling power source or forward/reverse motor rotating, please contact us.
  • Visual check label's printed ratings of voltage, power, frequency to meet field requirement.
  • Special care inspection shall be taken while one of the following condition been found:
    • Operation more than 200,000 times.
    • Abnormal noise or visual defect found.
    • Every six months interval upon contactors starting in service.

UHA Ratings - 3 Phase 40A~250A

Cat. No. UHA40 UHA63 UHA80 UHA100 UHA125 UHA160 UHA200 UHA250
Main Circuit Ratings
Continuous Current 40A 63A 80A 100A 125A 160A 200A 250A
Heating Current 60A 80A 100A 120A 150A 180A 220A 250A
Operating Voltage 450VAC 220V / 450V / 780V / 1350VAC
Clamping Voltage 820VDC
Synchronous Making Delay <50ms
Synchronous Breaking Delay <100ms
Withstand Voltage to Control Circuit >1,500VAC
Control Voltage (Ue) 110V 220VAC (75%~120%)
Voltage to Maintain Closing <50% Ue
Power to Maintain Closing 1.8W 3W
Triggering Signal Transistor Pulsing
Life Expectancy Electrical >1,000,000 times of ON-OFF operation
Mechanical >5,000,000 times of ON-OFF operation
ON-OFF Operation Frequent AC-3 1,000 time/hour
AC-4 600 time/hour
Auxiliary Contacts 2a 2b
Environmental Temperature -40°C ~ +45°C
Net Weight 2kg 2.2kg 5kg 5.5kg
Remarks [1] UHA contactor provides arc-less breaking feature, but does not provide Zero-Inrush making feature.
[2] Main circuit shall not be used for DC power.

UHA Ratings - Single Phase 80A~250A

Cat. No. UHA-801 UHA-1251 UHA-1601 UHA-2501
Main Circuit Ratings
Continuous Current 80A 125A 160A 250A
Heating Current 120A 160A 180A 270A
Operating Voltage 220V 450V 780V 1350VAC
Withstand Voltage to Control Circuit >1,500VAC
Clamping Voltage 820VDC
Control Voltage (Ue) 110V 220V 380VAC, 50/60Hz (75%~120%)
Power to Maintain Closing Voltage <50% Ue
Watt 1.8W 2W
ON-OFF Operating Times AC-3 1,000 time/hour
AC-4 600 time/hour
Electrical Life Expectancy AC-3 > 800,000 times
AC-4 > 1,600,000 times
Mechanical Life Expectancy > 5,000,000 times
Environmental Temperature -40°C ~ +45°C
Remarks [1] Available control voltage: 5V, 9V, 12V, 24V, 36V, 48V on request.
[2] Main circuit shall not be used for DC power.