All Dairyland decouplers block DC and simultaneously ground AC during normal conditions, and provide over-voltage protection during AC fault and lightning conditions. This demonstration can be used to simulate the decoupler’s performance during various field conditions.
DC Blocking Threshold: All decouplers have a stated DC blocking threshold voltage, most commonly -3 volts/+1 volt or –2 volts/+2 volts. Within this range, direct current is blocked, which is desirable in isolating cathodically protected structures from grounding systems and other equipment. Voltages at or beyond these limits put the device into conduction, and the decoupler will pass DC.