What should the resistance of an armature be when measured from commutator to ground with brushes removed?

The resistance of an armature when measured from the commutator to ground with the brushes removed should be high resistance. This is because a high resistance value indicates that there is no short circuit between the windings and the armature core, which is critical for the proper functioning of the motor.

In a properly functioning armature, the insulation between the conductors and the core must be intact. A high resistance reading signifies that the insulation is effective, minimizing the risk of current leakage to the ground which could cause damage or malfunction. If the resistance were low, it would suggest potential insulation failure, leading to possible short circuits, overheating, or unwanted current paths, all of which can be detrimental to the elevator's operation and safety.

Therefore, the ideal scenario is to achieve a high resistance reading, confirming the integrity of the armature's insulation and ensuring reliable performance.