A condition I encounter constantly during home inspections is electrical receptacles (outlets) that have been painted over. This is a very bad practice and should never be done. It creates two problems.
The first is that it plugs the holes in the receptacle with paint, which hardens, and makes it very difficult, if not impossible, to insert a plug into the receptacle. If you exert enough force to push the blades of the plug into the clogged receptacle, you may break the receptacle, the plug, or both. In some cases the paint must be dug out of the holes with a sharp tool, which should be done, obviously, only with the power to the receptacle turned off at the breaker panel. This first problem is obvious to the casual observer.
The second problem is not so obvious, and in fact is insidious, and potentially more serious. The paint also gets on the metal spring blades inside the receptacle. These blades are supposed to make firm, intimate contact with the prongs on the plug, and transfer the electrical power from the receptacle to the plug. If there is paint on these blades, it may prevent contact altogether, or worse, it may allow only partial contact, which creates a point of resistance to the flow of electricity. Any time electrical current flows through a resistance, it generates heat. The heat causes the metal contacts to oxidize. The oxide on the contacts is not a good conductor of electricity, so it creates further resistance, which in turn produces more heat. The situation becomes progressively worse until you can have enough heat to create a potential fire hazard.
If we are considering a modern, 3-wire, grounded receptacle, the hole in the outlet that is most susceptible to getting paint inside the outlet is the round (or ”U” shaped) hole for the ground prong on the plug. The grounding conductor in the circuit normally does not carry any current. It is there only to provide an easy pathway for any leakage or fault current to find its way safely back to the ground in the electrical panel. That’s why ground wires are not insulated; they are bare.
It is important, however, that any appliance equipped with a 3-wire, grounding plug, be used only with an outlet that is properly grounded. If there is paint in the hole for the ground prong, there is a very good chance that the ground prong on the plug will not make contact with the ground blade inside the outlet, and your appliance will not be grounded, which is potentially unsafe.
When I first plug my receptacle tester into a painted outlet, I quite often get an indication of “no ground” or “bad ground”. If I wiggle the plug around a little, the contact improves and I get an indication of good ground. That is a very iffy situation and is not acceptable. It’s an intermittent ground, and cannot be relied upon. You want to know that when you plug your computer into a receptacle, you have a good ground contact, every time.
Speaking of computers, most of us know that we are supposed to have a surge protector between the receptacle and the computer, to protect the computer from transient spikes of high voltage which are not uncommon on our power lines. The surge protector, however, relies on a good ground to operate correctly. The ground is where the protector “sends” the surge, if one comes down the line. If the ground prong on the plug of the surge protector is not making good contact with the ground blade in the receptacle, because of paint or for any other reason, you may not have surge protection at all.
If the receptacles in your house are all painted over, I strongly recommend that you replace them, just to be safe.
Added March 12, 2018 by T. Ray from NEC, National Electrical Code:
Section 110.12 Mechanical Execution of Work. Electrical equipment shall be installed in a neat and workmanlike manner.
- (A) Unused Openings. Unused cable or raceway openings in boxes, raceways, auxiliary gutters, cabinets, cutout boxes, meter socket enclosures, equipment cases, or housings shall be effectively closed to afford protection substantially equivalent to the wall of the equipment. Where metallic plugs or plates are used with nonmetallic enclosures, they shall be recessed at least 6 mm (¼ in.) from the outer surface of the enclosure.
- (B) Subsurface Enclosures. Conductors shall be racked to provide ready and safe access in underground and subsurface enclosures into which persons enter for installation and maintenance.
- (C) Integrity of Electrical Equipment and Connections. Internal parts of electrical equipment, including busbars, wiring terminals, insulators, and other surfaces, shall not be damaged or contaminated by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues. There shall be no damaged parts that may adversely affect safe operation or mechanical strength of the equipment such as parts that are broken; bent; cut; or deteriorated by corrosion, chemical action, or overheating.
|John Klima has over 30 years of experience in the field of inspecting residential, commercial and multi-family properties and has inspected over 10,000 buildings.|