Grounding in place of bonding. This causes dangerous differences in potential and sets you up for circulating currents. It sets you up for energy-wasting power quality problems. Any time you have mysterious power quality issues, first make sure the system complies with Art. 250, Part V. That alone may fix the problem, ending the need for many hours of testing, troubleshooting, and head-scratching.

Excess harmonics. A harmonics tester is a good investment. If you have excess harmonics, it means the equipment has to use more power to do the same work. One sign you may have excess harmonics is that thermograhic surveys show conductors to be hotter than they should be. That heat is wasted energy.

Low power factor. Motors are inductive loads, and they shift the power vector off of center. To shift it back, you add capacitance. This solution is often overlooked because there are already power factor correction capacitors at the service. But power factor correction at the service doesn’t fix the low power factor problem at the motor. You need to correct at the motor. Motors with variable speed drives are a special case; don’t just add capacitors or you may destroy the drive. If the drive is not harmonics and power factor corrected, contact the manufacturer to see what can be done.

High-resistance connections. These are just going to happen. The trick here is to find and fix them early in their deterioration phase. Regular thermographic surveys will find such connections if they are accessible. Inaccessible connections will require resistance measurements if a shutdown can be arranged or voltage (across each connection) if it can’t.

Load imbalance. Not only do load imbalances waste energy, they significantly shorten the lives of motors. Ideally, you’ll have a power monitoring system, and it will be looking at some specific nodes (such as feeders/branch circuits to critical motors). Your PM procedures should call for supply voltage measurements, and provide the tolerance range (in volts) based on acceptable voltage imbalance.

Unoccupied areas fully lit. It’s not so much that anyone needs an energy audit to reveal this problem; it's that management wants to pay for a facility’s energy savings work only after a formal audit. So even though everyone can see this problem, it doesn’t get addressed. But management is thinking in terms of the whole facility. So change the terms. The solution is to determine what lighting controls are needed for a given area and then write a specific proposal for that one area.