Liquid rheostat

In the simplest form it consists of a tank containing brine or other electrolyte solution, in which electrodes are submerged to create an electrical load.

In such cases anti-freeze and anti-corrosion additives must be carefully chosen to not change the resistance or support the growth of algae or bacteria.

The salt water rheostat operates at unity power factor and presents a resistance with negligible series inductance compared to a wire wound equivalent, and was widely used by generator assemblers, until 20 years ago,[as of?]

They are still sometimes constructed on-site for the commissioning of large diesel generators in remote places, where discarded oil drums and scaffold tubes may form an improvised tank and electrodes.

In such cases anti-freeze and anti-corrosion additives must be carefully chosen to not change the resistance or support the growth of algae or bacteria.

Disadvantages include: Railways commonly used salt water load banks in the 1950s to test the output power of diesel-electric locomotives.

[5] Massive rheostats were once used for dimming theatrical lighting, but solid-state components have taken their place in most high-wattage applications.

This requires connecting the container to both ground and neutral and breaking all poles with a linked over-current circuit breaker.