amps were lower on ohms law math than what I read with live at the equipment?
Several possible reasons:

1) The resistance is different when more current flows. The ohmmeter will put a small current, measure the voltage, and calculate the resistance. The actual circuit may be using a much larger current that changes the resistance (heating element)

2) The impedance is inductive (motor) or capacitive.

3) There is a residual voltage from a capacitor. The ohmmeter requires a completely powered off circuit.