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Reply To: Protection Riddle No.9 – Trip relay mal-operation

#1224
S.Muthukrshna

    Trip relays should be of high wattage type . The trip relay should pass a test of “Non operation ” for discharge current of 10 microfarad charged to the 1.2times rated voltage value through the relay. This is specified in some British electricity standards EB2. This is essential to avoid tripping when the other side (the one which is connected to the contact and not negative )of the trip relay coil is accidentally earthed (resulting battery earth leakage relay pickup) , during which time the capacitance due to contact connected to that trip relay coil discharges through the coil of the relay . Regards S.Muthukrshna