It has been suggested by the OP and supported by others that he use a current transformer. While they are non-contact, it will not work as the only sensor in the system. You cannot detect the absence of voltage when measuring current. Only when you know when current should be present and is not, will you know there is a failure.
This thread may be well intentioned but... this is how people get killed. I’m not joking here. From your own admission you’re not qualified to be working near this level of voltage and this is arc flash territory where you don’t need to touch anything to die. Just drop something metallic into the wrong place and you’re blind, burned or dead. You need to be discouraged, not encouraged, in thinking you can bodge together something for a 3 phase 415V system - because you cannot do that safely.
You should call the supplier of the compressor and get them to sort it or your company needs to hire a qualified industrial engineer to solve the problem. I’m certain Health and Safety would agree.
Hi,
How are you at the moment notified of the circuit breaker being tripped?
You would also need to measure motor and compressor temperatures.
Logging the results you are measuring would be of advantage, say storing the last 1hr or 1/2 hr so you do not need a great deal of memory.
Does the compressor motor have a controller or star/delta starting circuit?
I am surprised that a remote system like that does not have a 3phase monitor already fitted.
Ask your sparkies, if they know their job they should know about a monitor.
Can I suggest, if you have not already, get an electrician on site with you and measure the 3phase voltages and the 3phase currents with the compressor running and working.
The sparkie should be able to measure the starting current and starting supply voltage, his clamp meter should have MAX/MIN facilities, if it does not then he/she is using a toy.
This will be your base line, check how close that baseline is to the circuit breakers parameters and wiring that has been used.
("Multiple Electricians" has me afraid, very afraid.)
