ANNEX V
DEFINITIONS
An active electrical energy meter is a device which measures the active electrical energy consumed in a circuit.
I | = | the electrical current flowing through the meter; |
In | = | the specified reference current for which the transformer operated meter has been designed; |
Ist | = | the lowest declared value of I at which the meter registers active electrical energy at unity power factor (polyphase meters with balanced load); |
Imin | = | the value of I above which the error lies within maximum permissible errors (MPEs) (polyphase meters with balanced load); |
Itr | = | the value of I above which the error lies within the smallest MPE corresponding to the class index of the meter; |
Imax | = | the maximum value of I for which the error lies within the MPEs; |
U | = | the voltage of the electricity supplied to the meter; |
Un | = | the specified reference voltage; |
f | = | the frequency of the voltage supplied to the meter; |
fn | = | the specified reference frequency; |
PF | = | power factor = cosφ = the cosine of the phase difference φ between I and U. |