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Circuit breaker testers:
F.A.Q.
Frequently asked questions for Power Box
Q: The POB30AD current pulse width (DC) is 100ms. However, some Chinese customers want the pulse width of 700ms. Is it possible? Some old circuit breakers close pulse is about 700ms. Can the pulse width be adjusted?
A: DC pulse width (100ms) was chosen because our German customers specified it. The reason is possibility because a coil could be blown in the MT Volt menu.
In the MT Volt menu by pushing TRIG button, a pre-selected DC voltage lasting 100ms is brought to a desired coil. If coil was not actuated, voltage automatically increases for selected step, and after 900ms pause voltage is generated again, lasting 100ms.
If the DC pulse width is increased from 100ms to 700ms in the MT Volt menu, the coil could be overheated and because of that burn-out.
For that reason, we can offer two possibilities for your market:
1-We can adjust DC pulse width of 700ms in the Volt DC menu, but we have to keep pulse width of 100ms in the MT Volt menu.
2-We can adjust DC pulse width of 700ms in both, the Volt DC menu and the MT Volt menu, but we have to increase the pause from 900ms to 2,8s in the MT Volt menu.
Q: Please confirm that the POB30AD or POB30D can be equipped with the built-in thermal printer.
A: Our POB30D and POB30AD are only Power Boxes, and unfortunately they are not timers. Because of that, it does not make sense to build in a thermal printer. Very soon we are going to develop Power Box with the timer, and then our POB30D and POB30AD will be equipped with the built-in thermal printer.
Q: I wonder if the DC voltage of the power box POB30 can be adjusted continuously? For example, from 65V to 66V to 67V to 69V, and any value of voltage within the specs? For example, 35V, 40V, 134V etc.
A: We have developed two variations of power box, POB30D and POB30AD. The POB30D generates only DC voltage, and POB30AD generates both, DC and AC voltages. At our power box POB30D you can select any voltage from 10V up to 300V with resolution of 1V. At our power box POB30AD you can select any voltage from 10V up to 300V DC and from 10V up to 250V AC with resolution of 1V.
Q: What is the procedure to do the minimal trip voltage test?
A: Both devices POB30D and POB30AD have built-in function intended for automatic test of minimal trip voltage. You can choose the triggering voltage of the closing coil (or the breaking coil) on the switch by setting the minimal voltage, the maximum voltage and the step voltage. The device will automatically examine the minimal trip voltage of the coil.
Q: What is the difference between POB30D and POB30AD?
A: POB30D is upgraded and more powerful version of POB30. The POB30D can generate DC voltage at coils outputs. Besides DC voltage, the unit POB30AD can generate AC voltage, at coils outputs.
Q: We have bought a power supply type POB30 last year and would like to know if this device is suitable for testing of switchgear or it is suitable only for circuit breaker test? Because when we supply one cell of MV switchgear (contains Siemens protection relay, control relay, signal lamp in LV chamber) with setting voltage of 30V, the voltage changes from 10V to 40V and is not stable. It happens especially when the voltage is applied to binary input of relay for testing of supervision function.
A: All our devices have protection schemes. If the load draws current in excess of 26A, the voltage on our devices will start to decrease.
