Is it dangerous a low reading such as 1Kohm for IR I know you need to seriously investigate but if a 3 phase submersible pump is installed correctly wouldn’t the breakers/ fuses blow before the equipment is unsafe.
The measurements were at the motor. What do you mean by two faults. Obviously it’s not good but the pump is out of reach but has metal work connected to it. My understanding was if it’s well earthed the voltage should be minimal due to the resistance of R1 plus the 1000kohm. But also confused as to if it was to become dangerous wouldn’t the fuses take care of that considering the ZS is correct. Thanks guys
In a well-designed installation, one fault should not leave it unsafe. Either it remains safe to use, or a fuse or breaker trips to kill the power. It takes two separate faults to leave to an unsafe condition.
If you have 230mA leaking to earth, then you are relying on that earth connection being good and solid all the way back. If an earth wire comes adrift somewhere in that installation, then anything connected to the pump's earth wire will become live, with the ability to deliver 230mA to anyone touching it. That's easily within the current range that will kill someone, but also far too low to blow a fuse or trip a breaker. You have a one fault to dangerous situation.
The measurements were at the motor. What do you mean by two faults. Obviously it’s not good but the pump is out of reach but has metal work connected to it. My understanding was if it’s well earthed the voltage should be minimal due to the resistance of R1 plus the 1000kohm. But also confused as to if it was to become dangerous wouldn’t the fuses take care of that considering the ZS is correct. Thanks guys
In a well-designed installation, one fault should not leave it unsafe. Either it remains safe to use, or a fuse or breaker trips to kill the power. It takes two separate faults to leave to an unsafe condition.
If you have 230mA leaking to earth, then you are relying on that earth connection being good and solid all the way back. If an earth wire comes adrift somewhere in that installation, then anything connected to the pump's earth wire will become live, with the ability to deliver 230mA to anyone touching it. That's easily within the current range that will kill someone, but also far too low to blow a fuse or trip a breaker. You have a one fault to dangerous situation.
