|Definition:|| under steady-state conditions, the r.m.s. value of the difference between:|
the positive signs of the primary and secondary currents corresponding to the convention for terminal markings
- the instantaneous values of the primary current, and
- the instantaneous values of the actual secondary current multiplied by the rated transformation ratio,
NOTE – The composite error is generally expressed as a percentage of the r.m.s. value of the primary current.