This video will follow CCPIA Instructor Bob Aey as he performs an electrical inspection of the historic First National Bank in Rock River, Wyoming. The First National Bank was originally built in 1919, but has undergone more recent renovations. Some components of its electrical system were redone a year prior to Bob’s inspection. As you’ll see in this course, a recent alteration or repair on a building doesn’t mean that finding defects is less likely. Some of the defects are beyond the International Standards of Practice for Inspecting Commercial Properties (ComSOP), and more relevant to the National Electrical Code (NEC)® and the National Electrical Safety Code, or other local codes or regulations in effect.
Service Entrance Defects
Start the inspection at the service entrance with the point of attachment. The point of the attachment is where the utility company spans overhead wires to the mast. The mast is where the conduit is sticking above the roof.
- Service-drop point of attachment: The point of attachment should be at least 1 foot below the weatherhead. In the video, the distance is short.
- Coupled conduits on a mast: When conduits are coupled on a mast, the conduits should always be on the bottom. In the video, the short piece of pipe is at the top and the 10-foot pipe is below. The strain is greatest at the top of an overhead mast service. When the shorter piece of pipe is at the top, the support and strength of the mast may not be sufficient to hold the weight of snow, rain, wind, and other environmental factors. The mast may lean or collapse if not placed correctly.
- Straps on rigid metal conduit (RMC): Conduit straps are required every 10 feet. In the video, there should be a strap within 3 feet of the meter, and another within 10 feet. Strapping ensures that the conduit is securely fastened. Generally, RMC and electric metallic tubing (EMT) should be securely fastened within 3 feet of each outlet box, junction box, device box, cabinet, conduit, body, or other conduit termination. Additionally, EMT must also be fastened within 3 feet of tubing termination. Fastening can be increased to a distance of 5 feet where fastening can’t be secured within 3 feet. In some instances, the conduit isn’t required to be securely fastened within 3 feet of the service head for above-the-roof termination of a mast.
- Meter height: Most utility companies set the meter at a height of no more than 6 feet from the ground to the top of the meter. In the video, the meter is set too high and may cause accessibility issues. The minimum height required for an electric meter box is 4 feet from the bottom of the meter to the ground level. Some utility companies may have different minimum and maximum heights, but they’ll likely be within 1 foot of these requirements.
- Conduit sealing: Conduit that transitions from inside to outside must be sealed to prevent pests from entering and condensation from forming. In the video, the conduit was replaced but not sealed through the wall.
- Single-wire lugs: Single-wire lugs do not allow multiple wires under the same lug. In the video, there are two wires under a lug not listed for two holes. Wires should be terminated separately.
- Cracked main breaker: A cracked breaker typically occurs when the breaker is forced into position, excessive current or load occurs, or when the set screw enclosing the electrical wire in the breaker slot is too tight. The system may still function with a crack or chip in the breaker, but this is still a safety concern and should be addressed. In the video, the set screw below the breaker is pushed forward and twisted. It is likely that someone over-tightened the set screw, which cracked the breaker.
- Neutral-to-ground bond: The grounded (neutral) conductor should be separated from the metal parts of electrical equipment to prevent fire, electrical shock, and improper operation of circuit protection devices. This should be done in a manner that prevents objectionable current from flowing on conductive materials, electrical equipment, or on grounding and bonding paths. In the video, a ground wire is passing through a metal fitting. The fitting should be bonded on both sides. A common solution is a plastic fitting placed there.
- Service grounding: The service is required to be grounded typically with one or two 8-foot ground rods. In the video, there isn’t a ground rod present. It is typically under the ground’s surface, but in the video, the ground wire isn’t connected to anything. The service is essentially ungrounded.
Continue with the Historic Wyoming Bank Electrical Inspection Video Series