Sometimes in the rush to restore operation, one repair tech says to the other, "Why don't you button that up while I go remove the lockout tags and energize the system?" This approach can speed things up and save the company some lost production time. But it can also easily lead to fatal consequences and an extended outage.
To prevent tragedy, use a pre-energization checklist. It should include things such as:
- Visually inspect the terminations.
- Replace any disturbed seals (if in a Hazardous Location).
- Perform tool count.
- Inspect and secure all covers.
You might want to energize the equipment with covers open so you can watch your DMM. However, after making repairs, the risk of arc blast is especially high during the following energization, so energize the system with covers in place in case a repair error produced a fault. If you need to monitor voltages, one solution is to use a DMM with a remote display and secure it inside the enclosure.