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When testing E/M relays usually the 1-phase fault is the most critical one for any test set. The relay input transformers of the concerned phase and the neutral are serial-connected and form a much higher burden then for the other fault loops. With a CMLIB F the available output power of a CMA 156 current amplifier can be increased by a factor of 3 (210 VA at 7,5 A instead of 70 VA) for all single-phase fault loops.
Attention: CMLIB F is only applicable to schemes with a zero sequence element, where it is possible to contact the scheme coils according to the following test set-up (open star point):
