Service & Operations Office
Transformers | Load Tap Changers | Cooling Systems | Lightning Arresters
Voltage Regulators | Disconnect Switches | Circuit Breakers | Connections
Electromechanical regulators are used to regulate the voltage on AC power distribution lines. These regulators generally operate by selecting the appropriate tap on a transformer with multiple taps. The taps of a voltage regulator are inside the main tank and share the same oil as the transformer. If the output voltage is too low, the tap changer switches connections to produce a higher voltage. If the output voltage is too high, the tap changer switches connections to produce a lower voltage. The controls provide a dead-band wherein the controller will not act, preventing the controller from constantly hunting (constantly adjusting the voltage) to reach the desired target voltage. The primary connections to the voltage regulator are easily viewed with IR and should use the normal severity criteria for direct line-of-sight connections. The main tank is very difficult to diagnose and therefore we must incorporate ultrasound and oil analysis to complete these inspections. Each regulator in the substation will be under a different load since each circuit demand is different, thus creating more or less heating of these units. A hot contact inside will be masked by the large amount of oil, which is being moved and cooled during normal operation of most regulators.