A few set-ups of the experiments which are specified by the manufacturer for the normal intended use are subjected to EMC tests. The selection is made by the manufacturer, but from those with the highest interference potential.
7.3.7 Miscellaneous equipment and appliances :其他设备和器具
NOTE Limits in the frequency range 30 MHz to 1 000 MHz are not applicable to the devices quoted in 7.3.7.1 to 7.3.7.3, causing only discontinuous disturbance (see 4.2.1).
7.3.7.1 Time switches not incorporated in equipment or appliances
定时开关不装在设备或器具内
The switch is adjusted to maximize the value of n2 (the number of switching operations – see7.4.2.3). The load current shall be 0,1 of the maximum rated value, and unless otherwise specified by the manufacturer, the load shall consist of incandescent lamps.
For switches employing a manually operated "on" and automatic "off", the average "on" time (t1 seconds) shall be determined from three successive operations while the switch is adjusted to maximize the value of n2. A rest period of 30 s shall be allowed. The time for a complete cycle is (t1 + 30) s, thus the click rate N = 120/(t1 + 30).
对于手动”接通“自动”断开“的开关,平均“接通”时间(t1,单位s)用由将开关调节到使n1值最大三个完整操作确定。应允许有30s的间歇时间。真个周期时间为(t1 + 30) s,这样喀呖声率N= N = 120/(t1 + 30).
When measuring the disturbance voltage at the fence terminals of the electric fence energizer, the fence wire shall be simulated by a series RC circuit comprising a 10 nF capacitor (surge voltage at least equal to the no-load output voltage of the electric fence
energizer) and a 250 Ω resistor (the 50 Ω in parallel with 50 μH incorporated in the artificial mains V-network provides the balance of the required 300 Ω load resistance) connected as shown in Figure 6.
The limits for electric fence supply units apply to the mains terminals and to the output terminal of the supply unit. A correction factor of 16 dB shall be added to the measured values on the output terminals according to the voltage division resulting from the use of the fence equivalent circuit from the 250 Ω resistor in series with the 50 Ω impedance of the artificial mains V-network (see also item 5 of the legend of Figure 6).
The earth terminal of the fence circuit shall be connected to the earth terminal of the artificial mains V-network. If the terminals of the fence circuit are not clearly marked, they shall be earthed in turn.
NOTE In order to avoid damage to the r.f. input of the measuring receiver by the high energy pulses of the electric fence unit, it may be necessary to insert an attenuator before the r.f. input.