By Randy Yates, Technical Supervisor and Technical Training Administrator, NPI/GPI Corporate
When you’re buying a house, you want to know it’s safe. One of the main safety concerns is a home’s electrical system. Old wiring, improper outlets and an outdated service panel are problems often found in houses. Although older houses are at more risk for these issues, even newer houses can have electrical problems. This is just one more reason a home inspection is a good idea before you buy your dream home. Your home inspector will check all visible aspects of a home’s electrical system.
Inspection of the electrical panel should be performed only by either a licensed electrician or a trained property inspector — don’t try to inspect the panel yourself. Removal of the outer panel cover, and even removal of the panel-cover screws, poses a potential risk for electrocution. Your home inspector will approach the panel and first use either the back of their hand or a static electrical tester to check whether the service panel is energized — meaning there’s potential risk of electrocution from improperly installed interior panel wiring or the wrong type of screws to hold the panel cover in place.
(Flat-tipped screws should be used to hold the panel cover in place, not pointed-tip screws. The reason for flat-tip screws is that they reduce the risk of potential penetration into the insulation or sheathing that protects the wires inside the panel, which may not have been appropriately placed or safely tucked into the panel.)
Once the inspector removes the panel cover, he or she begins a visual inspection of the interior of the panel box. The inspector checks for and determines the size of the service coming into the house — how much power is coming in from the utility. The following are some other items an inspector checks for:
- Whether the panel has fuses or circuit breakers
- Properly sized wires coordinate to appropriately sized breakers
- Presence of double-taps — when more than one wire is connected to a breaker (unless the equipment is rated for such use)
- Dark, rusty or smoky residue on the panel
- Age and wear of the panel
- Improperly wired subpanels
- Wires run in a neat and orderly manner
- Presence of open splices or nicks in wires
- All connections are tight
A common finding is open knock-outs — holes or knock-outs that wires may have been passed through at one time but which are no longer in use. These holes should be closed or plugged so that in the event of an arc or spark in the panel, the occurrence can be contained within the panel.
If your home inspector finds problems with the electrical panel, he or she will recommend that the panel be evaluated and repaired by a professional electrician. Don’t skip this important step before you purchase a house; your safety depends on it.