Littelfuse's EL731 AC/DC Sensitive Earth-Leakage Relay

July 17, 2012
Relay can detect ground currents in resistance-grounded electrical systems
EL731 ac/dc sensitive earth-leakage relay can detect ground currents in resistance-grounded electrical systems down to 0 Hz to protect variable-frequency drives (VFDs) that operate at low speeds, during which ac current approaches dc. VFDs operating in resistance-grounded electrical systems are growing in popularity because of their ability to reduce arc-flash hazards.