"Inspecting Commercial Electrical Systems"

How could you tell this was Romex? I zoomed in and couldn’t see any identifying markings at all.

In person, standing on a ladder you can feel it, flex it, It’s been painted! Sorry for photo quality.

Electricity 101: Understanding the Service Panel
The homeowner should understand they have the ability to access their home electrical service panel to perform three tasks. First be know how to shut off power to the whole house, second be able to reset a circuit breaker that trips if it’s not a ground-fault circuit interrupters (GFCIs)and third know how to turn off power to individual circuits when required. The homeowner should understand that a 15-amp circuit consist one hot wire or 120 volts and it is on a single-pole breaker as well as that an electric range is a two hot wire, usually on a 50-amp circuit of 240 volts, and is connected with a double-pole breaker.
Common Electrical Conductor Types - InterNACHI
This article identified the reasons why inspectors should be wary of this old Knob-and-Tube (KT) Wiring system. The following information or knowledge is essential for the inspector as well as the potential knew owner expecting to remodel that old house. The cost to do so may be cost prohibitive. Beware of the following:

  • The dissipated heat from knob-and-tube wiring can pose a fire hazard if the wires are enveloped in building insulation. A possible exception is fiberglass insulation, which is fire-resistant, although even this type of insulation should not cover knob-and-tube wiring. The homeowner or an electrician should carefully remove any insulation that is found surrounding KT wires.
  • Knob-and-tube wiring is more vulnerable to damage than modern wiring because it is insulated with fiber materials and varnish, which can become brittle.
  • Some insurance companies refuse to write fire insurance for houses with this type of wiring, although this may be remedied if an electrician can verify that the system is safe.
  • Disregarding any inherent inadequacies, existing KT cable systems are likely to be unsafe because they are almost guaranteed to be at least 50 years old.

http://www.southwire.com/romex.htm

**The History of Romex®
**The Romex® brand of Non-Metallic Building Wire (“NM”) originated in 1922 with its development by the former Rome Wire Company, a predecessor to General Cable Corporation. On September 5, 2001, Southwire purchased the electrical building wire assets of General Cable Corporation. One of the most valuable assets purchased by Southwire in that acquisition was the Romex brand of Type NM cable. The Romex brand of Type NM cable has now been promoted and sold by Southwire and its predecessors for 88 years and Southwire considers its Romex trademark to be one of its most valuable brand names. Romex is a federally registered trademark and we vigorously monitor and protect the use of the Romex brand in North America and around the world. Don’t just look for generic NM cable, look for Southwire’s Romex® brand Type NM cable!

Subject property is a small (<2500 SF) retail store located in a strip mall. Panel capacity is 220V, 100 AMPS.

Note 1: Non-standard mechanical fasteners installed at dead front. Sharp screw tip(s) may damage wire sheath, and energize panel cover / enclosure. Recommend installation of listed, manufacturer-approved fasteners for this type of service panel.

Note 2: Service panel legend not properly marked. Current building practices require service panel legend to be clear, evident, and specific.

Note 3: Service increase and / or additional branch circuits will likely be necessary in the near future, depending on usage / load.

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This photo shows a “double tap” at a 15 amp breaker. In most commercial settings, the electrical panel dead fronts would not be removed. This installation was in a home that had been converted into a small business office. The electrical components & panel were typical of a residential application. I felt comfortable in this situation & removed the dead front during the inspection. The following comment was included in the written report:
Double tapping noted inside panel box (more than one electrical conductor attached to either a breaker or lug). This is not standard practice, and may cause overheating or even an electrical fire. Recommend evaluation by a licensed electrical contractor. Double tapping and lugging can create hot spots on breakers and neutral bars because they may not be tightened to the correct torque - especially if two different size conductors are used. Because the hot [black] and neutral [white]wires are both current carrying conductors, the chance is then greater for potential hot spots. If the double tap or lug becomes loose, it begins to arc. As it arcs it builds up carbon. Carbon is then resistance and with more carbon buildup the more difficult it is for the conductor to make contact, thus increasing the current. The end result can be the breaker tripping because of the loose connection [current exceeding the rating of the breaker], or signs of overheating such as discoloured or melted wires. I recommend further review, for correction as needed, by a licensed electrical contractor.

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The photo shows several aluminum wires visible within the electrical panel. As mentioned in my previous post, this was a small <1200 sq. ft house (built in 1971) that had been converted into office space for a small tax preparation business. I felt comfortable in removing the dead front during the inspection process. Because aluminum wiring was present, the following comment was included in my written report:
Aluminum wiring present. Between 1965 and the mid 1970’s, aluminum wiring was sometimes substituted for copper wiring in residential electrical systems. With aluminum wiring, connections in outlets, switches, and light fixtures can become increasingly dangerous as time passes. Poor connections can cause wiring to spark and overheat, creating a potential hazard. Aluminum wiring connections are subject to greater deterioration than copper due to thermal expansion and contraction, vibration (caused when electric currents pass through wiring), oxidation (caused by exposure to oxygen in the air), and galvanic corrosion (caused when two different metals are connected together), all of which can cause poor connections over time. The wiring connections should be evaluated by a qualified electrical contractor experienced in maintaining aluminum wiring systems.

As part of the writing assignment, I’ve chosen to write about “central humidification”.
A central humidification system, as part of a forced air heating system in a home, can provide numerous benefits to the homeowner. Suitable indoor humidity can help to control the “drying out” effect that can occur with items such as wood flooring, furniture and various musical instruments. Static electricity is also minimized. Excess indoor humidity should be avoided. Negative health effects to the occupants can result. Too much airborne moisture also leads to condensation build up which can result in damage to the home. Monitoring of humidity levels & regular maintenance of the humidifier is key. A poorly maintained, leaky humidifier, can be damaging to the heating system.

For one of the written assignments in this course, I’ve chosen to write about the hazards of a “crawlspace”.
As part of the inspection process, a home inspector will be exposed to various crawlspace settings. Some will be clean, well lit and relatively simple to inspect, while others may be dark, damp and contain various hazards. Part of the preparation prior to entering the space should include donning any necessary personal protective equipment. A good flashlight will also be necessary - a second “back-up” flashlight is never a bad idea.
Hazards within the space could include the presence of mould and fungus, various pests (I once encountered a skunk), rodent activity, standing water, areas that are confined and possible structural hazards. The safe inspection of a crawlspace should always be done carefully and include the necessary protective gear.

Articles chosen: AFCI Testers and IR Cameras: Electrical Inspections

Branch circuits equipped with AFCI-protected circuit breakers should be tested with a portable test device, rather than relying on the “TEST” button on the breaker, which cannot detect arc-faults within portions of the branch circuit. Also: The portable AFCI test device is an “indicator” rather than a “tester”, as it does not produce an actual arc fault, but simulates conditions that would cause a properly functions AFCI to open.

The IR Camera can increase the speed and accuracy of electrical inspections by allowing the inspector to sweep a large number of terminations in a very short time. Discrepancies such as improperly terminated lugs or over-fused wires will be evident with minimal physical contact with the electrical equipment.

Dan Fryer

This picture shows the electrical components contained in an electrical room of a 6200 sq.ft.commercial property. This system also feeds power to a workshop and 18 small efficiency rental cabins.
We can clearly see the three main switch panels that provide power to the main lodge and the cabins. The smaller of the three switch panels located in the middle provides power to a workshop located on the property in a separate building. The four small switch panels provide power to equipment located within and around the building. The gutter box distributes and divides the incoming 600 volts/3 phase power to the different components contained within this system. It also receives power from a backup generator actuated by an ATS and feeds the backup current to a emergency power breaker panel that is outside of this photo. There is an outside pole mounted transformer feeding power to this system from the local utility company. The size of the transformer was not verified.
Due to the size and complexity of this electrical system the writer acted in the capacity of a facilitator and enlisted the assistance of a 3rd party master electrician prior to completing the written report to the client.

The articles read were both related to electrical panels and homeowner safety.

The electrical distribution panel can contain either fuses or breakers. Both of these items measure the current draw on individual electrical circuits and senses when this draw becomes excessive and opens the circuit, or as in layman’s terms "trips the breaker’ or “blows a fuse”. They can be reset or replaced but if this should happen again it could be an indication of an underlying problem that should be sorted by a qualified electrician. The primary rule of thumb is to not have too many appliances or lights on one single circuit.

For the homeowner there are generally no user serviceable components within an electrical distribution panel and unless properly trained should stay out of this area of their home. Severe electrical shock can result from working with the electrical system of a home. Always consult a qualified electrician to perform electrical work.

ELECTRICAL RESIDENTIAL INSPECTIONS ESSAY

In my studio apartment I have a 240-volt 4-wire system in the sub-panel. Once I removed the dead front I was able to expose the wiring. The SEC are wired from the bottom; but are correctly bushed. There is no sign of multi-tapping, arching, or moisture in the panel. The GFCI breaker test worked properly. One correction I would suggest is replacing the missing knockout to prevent any hazards.

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Commercial Electric1.jpg

In this inspection assignment on the Commercial Electrical course, I choose this picture of an outside electrical outlet on a brand new Physical Therapy Clinic building. I was chosen to do a sixth walk through to see if the owners had missed anything on their first walk through. What makes this picture so interesting is the fact that I was the six person to do a walk-through. First was the subcontractor, then the General contractor who called in the county Electrical Building Inspector who approved the permit. Then the walk through with the two owners and the General on the punch list. None of these inspections found this outlet. On my walk through inspection, I found this outlet with these wires hanging out. Putting my tick tester on them, I found they were live wires. I called the owners, who called the General who called the Sub-Contractor who came out and fixed it within thirty minutes. This is common in this area to see obvious workmanship flaws passed by the government inspectors. Although government inspectors may not find concealed issues, they should have found this very obvious one, not to mention all the other people that had walked through this new building.

In my reading assignment on the Commercial Electrical course, I chose the “Personal Safety at a Commercial Property.” This article discusses the how with simple basic procedures and methods, commercial property can be made safer for the inspector, occupants and visitors. Outside security measures can include outside building lighting. This can includes parking lots, walk ways, doors and secluded areas. Inside measures can include alarms, window coverings and recording camera systems. Personal protection for inspectors should include locking vehicles and watching locations for possible criminal activities. It’s also important for the inspector, tenants and visitors to be alert to unknown or suspicious vehicles or people on location. Overall, it’s the inspector, occupants and visitors who should be aware of their surroundings at all times and take appropriate actions to best protect themselves.

In the second reading article, I chose “Reserve Studies.” This article describes the use of Reserve Studies by Home owners association as a budget planning and execution tool. The use of these studies are broken down into two areas. One is the physical examination of all the shared land, buildings and extra items that would benefit the homeowners. The other is a financial cost analysis of repairs, new construction plans and maintenance requirements. Also included in this analysis is the income from home owner fees, any bank accounts or other income producing methods. These studies can be used as an analysis to the status and rating of the association. The results may determine an increase in home owner fees, new construction projects or even finishing deferred maintenance projects. Overall, these formal studies help determine the condition of the shared spaces in relationship to income of the homeowners association.

This is an image of some electrical panels in a commercial setting. There a three Cutler-Hammer 200 amp panels that are marked 120V/207V, as well as three panels that were marked for lighting control relays. Inside the panel (the dead front had been opened by a licensed commercial electrical contractor), the circuit breakers were 15 amp, however the wire size was 12 gauge, to facilitate upgrades to 20 amp if necessary in the future. What was called out was the fact that clearance in front of the panel was not maintained (storage of items in front of panels).

Flange
Blind Flange
Threaded Flange
Weld Neck Flange
Slip on Flange
Socket Weld Flange
Lap Joint Flange
Pipe Flange

This is an image of an older electrical service panel(s). The main electrical panels are two different manufacturers one is Square D and the other is Federal Pacific. The Square D panel is also an older style as it is not similar to the current Square D types. The Square D panel has its main breaker disconnect in a separate enclosure from the section with all the branch breakers. The Federal Pacific panel is also fed from the Square D main disconnect and is likely double tapped but the cover would have to be removed to verify. The federal Pacific panel would be noted as a brand that is problematic and should be further evaluated and or replaced. The Federal Pacific panel is known as a split bus meaning that it does not have a main breaker and the lighting and general use bottom section is serviced by a two pole breaker in the upper main buss section. Likely the Federal Pacific panel is not original and was added after the older Square D panel was installed.

Service drop clearances measured in feet and inches is something to pay close attention to. There is not one specific height that works for all instances for example 18 feet is required over a roadway and 12 feet over a driveway. 22 1/2 feet is required over a swimming pool. To complicate matters the serving utility company may have requirements that are more strict than the NEC for example here in the Northwest the utility companies require 14 feet over a residential driveway. Often times decks will be built after the fact thus reducing the clearance to below the required minimum. It would be wise to make a cheat sheet so as not to have to remember all the different numbers.