Robust and low maintenance

The design of a Liquid Neutral Earthing Resistor is a large tank containing an electrolyte solution (distilled water with a small amount of electrolytic powder). The outer case of the tank is connected solidly to the earth point. An inner electrode which is insulated from the tank, is the HV connection to the transformer or generator star point. At commissioning, small amounts of electrolyte are added to the water to increase the conductivity of the solution until it reaches the calibrated resistance level. The final result is a high current carrying capacity fluid with a high resistance, in a very robust and low maintenance package.

Neutral Earthing Resistors can be fitted with:

• Heaters and thermostats to ensure frost and ice are never a factor
• Condensation traps to return evaporate to the tank, significantly lengthening the time required between corrective measures
• Fluid level detection and low level alarm devices to ensure the correct operation is always maintained
• Inspection hatches for ease of maintenance
• CT housings and Current Transformers for earth fault protection devices
• Direct overhead line or underground cable connection options
• Lifting hooks and jacking lugs.

Acrastyle’s Neutral Earthing Resistors are made from stainless steel and many have achieved 30 and 40 years plus of trouble-free service.