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.
That really does need to be investigated. The RCD is an extra level of protection but should never be relied upon if possible. RCD's can fail, especially if they are overloaded over an extended period, or very overloaded over a short one. Hence the requirement for regular testing and using the button.
Find and treat the cause of the problem, don't rely on an RCD to deal with the symptoms.
Final thought, if it is a 3 phase with neutral and the motor is connected in star mode, then the low reading could be due to current coming back through the windings to neutral, which is also connected to earth. Disconnect the neutral for your measurement.
That really does need to be investigated. The RCD is an extra level of protection but should never be relied upon if possible. RCD's can fail, especially if they are overloaded over an extended period, or very overloaded over a short one. Hence the requirement for regular testing and using the button.
Find and treat the cause of the problem, don't rely on an RCD to deal with the symptoms.
Final thought, if it is a 3 phase with neutral and the motor is connected in star mode, then the low reading could be due to current coming back through the windings to neutral, which is also connected to earth. Disconnect the neutral for your measurement.
