Machines or Equipment Resetting

A common problem that can be diagnosed with a good voltage recorder is the resetting of electrical machines that have electronic, PLC or computer controls, where the resetting is caused by the supplied voltage. There are several causes that can precipitate resetting.

High average voltage supplied to the electronics power supply unit (PSU) can cause it to trip out on an 'overheat' fault, likewise low voltage can also cause overheating of the power supply tries to deliver the necessary energy to the electronics.

Low supply voltage can also cause the PSU to drop out as it simply cannot maintain the required output voltage, so will run out of energy and drop out albeit momentarily.

An intermittent voltage supplied to the PSU can cause a reset, as some PSUs do not have a long enough ride-through, so if the supplied voltage drops (even for a shot period) the PSU cannot deliver energy when it is receiving none or too little from the supplied voltage. This has become more common as PSUs are being built more cheaply with less materials, less components therefore less weight; designers are not building in any appreciable ride-through capability. Intermittent supply or drop outs can occur if the power company is performing network switching operations. It can also be caused by local wiring issues like poor connections or wiring within the premises. There are other causes.

You can use a voltage logger like the EC-1V, EC-2V or EC-3V to record the supply to the machine and look for high, low or intermittent voltage. These loggers can see drop outs of 1/2 to 1 cycle. A cycle is 20ms on 50Hz system or is 16.6ms at 60Hz.