These three tests should be in your preventive maintenance program for medium-voltage circuit breakers: 1. Contact resistance test. Use a digital low-resistance ohmmeter (DLRO), not a digital ...

Using the multimeter at the one box will allow you to discover which of the wires is the continuous hot wire that has power when the circuit breaker is on. Mark this wire once you determine this.

When it comes to choosing a multimeter for servicing refrigeration systems, there are a lot of choices on the market. Careful planning should go into selecting the right meter.