HV Probe & Proving Units



  • Ergonomic design
  • Portable and robust
  • Probes are passive in operation, no power source required
  • Proving unit to verify probes before and after tests
  • Proving unit supplied with a standard 9v battery (PP9)


  • Prove circuits dead
  • AGL circuits
  • Fixed ground power units


  • 55 – 5000 VAC
  • 75 – 7500 VDC

Planning for the future.

Leeds Bradford International Airport has just completed an upgrade of its airfield lighting control system infrastructure from Airfield Lighting Systems UK Limited (ALS) in Wickford, Essex. 

Leeds Bradford International Airport is seeing passenger numbers increase and more flight movements and is expecting to see this increase further following Covid restrictions lifting.

The upgrade saw 18 MCR400 Constant Current Regulators installed at the Airport to provide more versatility and control options for the various lighting circuits on the airfield operations.

ALS have been manufacturing CCR’s for many years and have a close working relationship with Leeds Bradford.  The CCR’s were specified and a full training program was provided recently by the company’s technical experts on site. 

Constant Current Regulator MCR400

The constant current regulator MCR400 is the “most popular” in a line of regulators specifically intended for the supply of series circuits for use on airfield lighting circuits.

To comply with statutory regulations, the CCR cabinet housing is divided into three areas, electronic control, low voltage area and main high voltage area.

The electronic control area is situated behind a hinged panel at the front of the cabinet with no access to the other areas.

The constant current regulator MCR400 is supplied as a free-standing unit, with or without castors. Requiring minimum floor space, it is available in ratings from 1.5kW to 30kW.

With the standard high speed built in serial data communications, the Constant Current Regulator (CCR) can communicate with most PC or PLC control systems