Toolbox
Protection and MV calculators
Transformers, fault levels, CTs, relay curves, earthing and power factor, from a protection engineer.
Transformer full-load current
Primary and secondary current from kVA and voltage.
Short-circuit current
Fault level at a transformer secondary from %Z.
IECCable size with derating
Tabulated rating needed after IEC derating factors.
IECCT burden
Connected burden and effective accuracy limit factor.
IECIDMT relay time
Operating time on the four IEC 60255 curves.
Earth rod resistance
One driven rod from soil resistivity and length.
Power factor correction
Capacitor kvar to reach a target power factor.
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