The Measuring Instruments (Active Electrical Energy Meters) Regulations 2006 (revoked)

Rated operating conditionsU.K.

This section has no associated Explanatory Memorandum

14. The manufacturer shall specify the rated operating conditions of the relevant instrument, in particular—

(a)the values of f_n, U_n, I_n, I_st, I_min, I_tr and I_max that apply to the relevant instrument. For the current values specified, the relevant instrument shall satisfy the conditions given in Table 2;

Table 2

	Class A	Class B	Class C
¹ For Class B electromechanical relevant instruments I_min ≤ 0.4 · I_tr shall apply.
For direct-connected relevant instruments
I_st	≤ 0.05 · I_tr	≤ 0.04 · I_tr	≤ 0.04 · I_tr
I_min	≤ 0.5 · I_tr	≤ 0.5 · I_tr	≤ 0.3 · I_tr
I_max	≥ 50 · I_tr	≥ 50 · I_tr	≥ 50 · I_tr
For transformer-operated relevant instruments
I_st	≤ 0.06 · I_tr	≤ 0.04 · I_tr	≤ 0.02 · I_tr
I_min	≤ 0.4 · I_tr	≤ 0.2 · I_tr¹	≤ 0.2 · I_tr
I_n	= 20 · I_tr	= 20 · I_tr	= 20 · I_tr
I_max	≥ 1.2 · I_n	≥ 1.2 · I_n	≥ 1.2 · I_n

(b)the voltage, frequency and power factor ranges within which the relevant instrument shall satisfy the MPE requirements are specified in Table 3. These ranges shall recognise the typical characteristics of electricity supplied by public distribution systems;

(c)the voltage and frequency ranges shall be at least—

(i)0.9 · U_n ≤ U ≤ 1.1 · U_n;

(ii)0.98 · f_n ≤ f ≤ 1.02 · f_n;

(d)the power factor range shall be at least from cosφ = 0.5 inductive to cosφ = 0.8 capacitive.