by Gilbert Migirditsian, professional engineer, home inspector, and founder of GM Inspection
The electrical system in any building is possibly one of the most complex components in any building application. Electricity is not only misunderstood and feared but is rarely treated with the respect it demands. In most situations, major issues are dismissed as requiring further investigation while in others have major red flags for mainly minor issues. This article will present some of the major elements one needs to keep in mind in one of the biggest financial decisions most will ever make.
There are main components that are essential to the electrical grid in any property. First, and foremost, is the electrical supply provided by the utility. This is the wiring that is entering your electricity meter from either an above ground or underground supply. Next, is the presence of the electricity meter itself where, for residential properties, only the electricity consumption, in kWh is billed to the customer while power, in kW fits into a typically allocated amount through service standards. The next element present is a main breaker that will essentially ensure that the main service panel is protected from an general overload. This element is measured in amps where a typical panel is anywhere from 100 amps to 800 amps with the possibility of many sub-panels is not uncommon, each having their distinct breakers. The voltage rating for the majority of residential applications are 120/240 volt combinations. But what are volts and amps exactly? Using plumbing as an analogy is a simple way of explaining the concept where voltage can be equated to water pressure and amperage equated to the flow rate. Using this analogy, a greater voltage is represented with a high pressure water jet and a greater amperage is comparing the flow of water in a bathtub to that of a kitchen sink being of lower amperage here.
When looking at the exterior of a property, the first issue that needs to be looked at is the way the electrical connection is made from the utility to the mast on the building or to the main junction if an underground connection is present within the property. For an above ground junction, a loop is required such that water can drain away from the connection and therefore avoid any water infiltration into the building or, even worse, into the electrical panel itself as we know water and electricity don’t mix well with one another. The electrical connections are typically protected by protective covers or electrical tape where covers are the preferred medium due to their longevity and increased protection. Many different configurations are possible anywhere from the typical mast presented in this article to a trestle allowing an electrical connection to traverse a building in its entirety before a connection is made on the opposite side of a property.
There are many types of wiring that may be found within a typical residential property such as Romex, armored BX, single strand wiring, and others. The most typical types of materials found on residential applications are aluminium cable, copper cable, along with knob & tube wiring that was typically installed around the turn of the 20th century. Copper cable is what can be found in most modern homes but what about all the worry that is generated by aluminium as well as knob & tube wiring? When comparing the two options, aluminium cable is the one that can best be managed by a licensed master electrician. The main issues with aluminium wiring is its tendency to oxidize, is easily nicked, and its thermal differences with copper that make it possible for the conductor to become loose in a connection. All these issues are cause for concern where overheating or sparking may cause a fire. The good news is that aluminium wiring can usually be managed by a master electrician with inhibiting paste to impede oxidation, an inspection at terminals to ensure no damage is present, and a tightening of connections that may have become loose over time. Unfortunately, when looking at knob & tube wiring, the only realistic solution is suggesting a rewiring of the property.
When inspecting past the main service panel, it is important to ensure that outlets are correctly wired both on all floors and near any sources of water such as a kitchen sink, bathroom sink, or even a spa in situations where one is present. Without getting into the technical details of the purpose all conductors serve in an electrical circuit, a simple tester plugged into an outlet will show any reversed wiring, ungrounded outlets, or outlets without electrical supply. Any issues pointed out at this point may be resolved with solutions as simple as correcting reversed wiring up to localized or generalized solutions for ungrounded outlets. Wiring issues must be handled carefully especially when dealing with the future installation of sensitive electrical appliances like TV’s, servers, and other expensive equipment. The use of an adequate power bar is also a must where the protection level often does, in this case, follow the price we are paying and the bargain basement model is far from being recommended.
Finally, more generalized problems like dimming lights, blinking lights, frequently burned out bulbs, and overheating of junctions require a more careful look at possible underlying issues. This can be as simple a matter as undersized wiring, oversized electrical equipment, or a minor electrical issue. More serious problems may be present such as overheating require careful attention of an experienced professional such as an engineer before a course of action is undertaken. An electrical inspection requires a large amount of experience which is why most inspectors will immediately defer to another person without taking any position on issues at hand. See you next time when I’ll be back with more useful information! In the meantime, visit us on Facebook.