A 3 phase wye-connected, 115 V, 400 Hz generator is used to power a test stand in which a motor controls a wiper arm that operates a three phase Variac to control the voltage across each of the phases. A DVM is used to measure the voltage across one of the phases with respect to earth ground.
The problem is that at the end of a test, the computer controller activates the motor to bring the phase voltage down to 0 V, but the meter measures 3 to 7 volts ac. This causes the test to fail.
The neutral doesn't appear to be connected to earth ground. A resistance measurement between the neutral and earth ground gives about 500 kohm.
Any insight as to why there would be such a high resistance between neutral and ground and what I can do to eliminate the residual voltage being measured from the meter?