Kicking the Tires

Kicking the Tires

What is Electrical Equipment Testing, and What Does it Do For Me?

June 18, 2018 by Greg Pink

Fiat Chrysler recalled almost 4 million vehicles in 2017; the most of the major car manufacturers. While in most cases the owners of these cars won’t have to pay for the maintenance, they will have to deal with an unplanned disruption to their schedule. Unlike regular planned maintenance like checking the tire pressure, changing the oil, and replacing the brakes, irregular breakdowns are a shock, inconvenient, and the repair bills leave a sour taste in your mouth.

Electrical systems in buildings are approached in the same manner. When we install a new system in a building, we expect it to operate safely without any major issues for the duration of its life. We know that to reach this lifespan, some regular maintenance is required. If a major component fails before the end, the sour taste is there again as not only is it inconvenient to deal with a major disruption to building operations, room must be found in ever-shrinking budgets to afford the costly repairs.

So what do we pay attention to? I don’t run around my car every morning and make sure the headlights and tail lights are on, but I do check my oil every time I fill up to make sure I am not running low. If a headlight goes out, it is a minor inconvenience and a cheap, quick fix. However, if I run low on oil in my engine, the cost and repair time are significantly more.

The same logic can be applied to electrical systems. Branch panels, breakers, wiring, and devices are not the place to spend your budget dollars; repairs are inexpensive and the parts are usually available locally. Where you want to spend your time and money is the main switchboard, distribution panel, transformers, and the similar high-power devices. If this equipment fails, the downtime could be weeks or months, and the cost can reach well into the tens of thousands of dollars. The general rule of thumb is: The equipment with high energy ratings should be tested more frequently and thoroughly than equipment with low energy ratings.

Electrical equipment testing can be loosely categorized by two types: Acceptance and Maintenance testing.

Acceptance Testing is typically broken into four major parts. All of this is performed before a building is granted occupancy.

1. Factory Testing – Major electrical equipment is tested before it leaves the factory to ensure that it has been constructed properly and meets the design specifications.
2. Arrival Testing – Coming off the truck, the contractor performs additional tests. These are often the same or very similar to the factory tests and serve as an assurance that the equipment was not damaged in transit. This is especially important for major switchgear, transformers, or motors where significant bumps or movement can affect operation.
3. Installation Testing – This is performed once the equipment is installed and connected to the rest of the system. The intent is to catch any wiring mistakes, labelling errors, or damage during the construction process.
4. Pre-Energization/Functional Testing – This testing is a dry run of the system. The object is to ensure that all the components, which were individually tested, are connected properly and will work together to power the building, report the status to the building operators, and perform as expected in emergency situations.

Maintenance Testing is performed at regular intervals throughout the life of the equipment. Just like you check the tire pressure and tread on your car to help predict if you need to budget for a set of new tires, the electrical system in a building must be checked to predict when equipment needs to be replaced. Frequent testing, along with the baseline set by the acceptance testing, can provide a history for the system. The history provides valuable data on important metrics, such as insulation degradation, that can be analyzed for trends. This allows a trained technician or engineer to tell how the system is aging or if there is something urgent that needs attention. This is hugely advantageous to building owners or maintenance managers who need to plan budgets years in advance.

Unfortunately, maintenance testing is often one of the first things to be cut due to the perceived costs and inconveniences. However, these tests need not be a significant endeavor. Most equipment needs a visual inspection every 2 months and a mechanical inspection every 12. The mechanical inspection often includes operating the components, such as opening a circuit breaker to ensure the moving parts have not seized, or lubricating parts that are frequently used like switches or contactors. Depending on the life expectancy and critical nature of the equipment, electrical tests are only required every 12-36 months. These tests tend to be more involved like testing the insulation of a cable, taking a sample of the transformer insulating fluid, or verifying a protection relay’s operating points and timing.

The visual and mechanical inspections can usually be done by competent building staff, but electrical inspections require specialized equipment and should be performed by a trained technician. Scheduling the electrical tests might involve power system outages of a few hours, but many can be performed in the evening or on the weekends when disruptions are minimal or combined with other planned work such as HVAC servicing.

Overall, periodic maintenance is cheap insurance against unplanned, costly, and lengthy power outages and service disruptions, especially in critical buildings or applications. Testing and scheduled maintenance should be performed frequently on high-energy equipment such as switchboards, distribution panels, transformers, and associated equipment. Visual and mechanical checks, along with a history of detailed testing sheets from qualified technicians, allow building owners to schedule equipment replacements at convenient times and budget accordingly.