Audit Equipment Inventory

The first step in conducting a power quality audit is to inventory the electrical equipment in the facility. Begin by making a hand-drawn diagram of the facility. Be sure to show the approximate location of each major area of the facility.

For example, supermarkets typically have: a front office area, a video display/rental selection location, multiple cashier or check-out islands, a pharmacy, a deli, a meat market, a produce section, a bakery, and stock storage areas.

The diagram will help the auditor envision the relative locations of electrical equipment, major electric circuits, and help keep the auditor from overlooking valuable information or an important piece of equipment.

Next, conduct the actual physical equipment inventory. Make sure the forms are labeled to match the various locations indicated on your facility sketch. Include space on the inventory form to record the following:

  1. Physical area and location of each piece of equipment,
  2. Name or description of the equipment,
  3. Electrical name-plate data (if required),
  4. Electric panel and circuit which feeds the equipment, and
  5. Symptom and frequency of any operating problem.

Walk through the entire facility and make a list of every piece of electrical equipment used. Ensure that everything from the largest electric motor to the smallest electronic device is included.

Note which electrical panel is feeding each piece of equipment. This information will help in isolating critical power loads from other electrical equipment that can cause problems, such as HVAC motors, saws, photocopiers, and water coolers.

Many panels will already be labeled with the loads they serve, others may not. Verify the labels and note any mismatches. If panels are not labeled, or wiring diagrams either are not correct or not available, this is a good time to update them. To determine electric feeds, systematically turn off each electric breaker and note which pieces of equipment lose power. Since this can disrupt the customer's operation, it should be done during non-business hours, if possible.

Be sure facility personnel (who are familiar with the electrical equipment) are on hand, and that the facility electrician or an electrical contractor takes care of flipping the breakers.