by John Rimer — Originally published in the March/April 2017 issue of FMJ
With the progressively more complicated and interdependent facility systems, the importance of maintenance continues to increase, as does the strain upon staff and contractors. There are regulatory requirements to inspect and test exit signs, fire suppression and detection systems, elevators, etc. Mechanical systems have their prescribed filter and belt changes, inspections and cleanings, and the more in-depth semi-annual and annual preventive measures.
There are so many demands clamoring for the facility department’s attention. While mechanical systems typically spring into the limelight with their whiz-bang pageantry, whirring moving parts and melodic noises, we cannot forget to grant due attention to the electrical systems — the sleeping giant, lumbering in the corner, powering these shiny, prominent fixtures at the flick of a switch.
Electrical maintenance, while not labor intensive, is necessary. In fact, studies have reported that circuit breakers, for example, stand a 50 percent probability of failure within five years, if not maintained to the manufacturer’s recommendations.
Breakers can fail one of two ways: open or closed. If the breaker fails open and cannot be reset, all systems, customers, etc. downstream of that breaker are indefinitely dead in the water until a replacement for the outdated breaker can be found. Alternatively, if a circuit protection device fails to open (fails closed), the next breaker up the food chain should trip. However, this assumes that it doesn’t succumb to the 50 percent failure probability and that the short circuit coordination was properly implemented.
Ultimately, the building main breaker could open, dropping the load for the entire facility all because a vacuum cleaner on the fifth floor shorted out (it happens). Or worse, the electrical anomaly necessitating activation of the branch circuit breaker could cause the breaker to overheat, damaging equipment, injuring personnel and potentially igniting a fire. Consider the age(s) of your electrical infrastructure and the last time sufficient maintenance was performed. What risk are you passively accepting on behalf of the organization?
Electrical maintenance is relatively simple, especially for circuit protection devices. Manufacturers typically recommend three types of maintenance: mechanical exercising, infrared thermography and current injection testing. These are also recommended by NFPA 70B: Recommended Practice for Electrical Equipment Maintenance, a standard of the U.S. National Fire Protection Association which outlines recommended preventive maintenance for electrical systems.1
A Word of Caution
Only qualified personnel, as defined per NFPA 70E, should perform any of these activities. The Occupational Safety and Health Administration (OSHA) states that proficiency must be demonstrated by an employee before being deemed “qualified.”
Also, note that OSHA’s standards in Title 29 of the Code of Federal Regulations extend beyond scheduled maintenance to include something as elementary as the reclosing of an opened breaker. In other words, only properly trained staff donning the appropriate protective gear are at liberty to reset a tripped breaker; and that is only after it has been proven that the protection device can be safely closed and the fault has cleared.
Here are some crucial questions to pose (and resolve, if applicable):
- Who is resetting breakers at your facility? Security? Custodial staff? Office personnel?
- Are there lights that are turned off and on at the breaker panel? Who performs those duties?
- Are facility staff qualified to investigate and reset breakers?
It is incumbent on the facility management staff to perform due diligence by identifying and addressing risks such as these.
Prescribed Maintenance Practices
Let’s return to the impetus of this article and further discuss the prescribed maintenance practices.
Exercising is the opening and closing of a protection device to ensure proper mechanical operations. Simply stated, it means to open and re-close a circuit breaker, for example. This tasking is truly a case of “easier said than done,” as interrupting electrical power, even temporarily, is seemingly impossible for most entities — business stops for no one. However, these efforts are necessary to provide safe and operational facilities. Consider the coordination of these simple, routine efforts practice for orchestrating the far more intensive breaker testing.
Infrared thermography, also known as thermal imaging, is a predictive maintenance that visually represents temperature differentials, identifying areas of concern and needed resolution. Thankfully, the cost of infrared cameras has decreased significantly from the six-figure amounts of 20 years ago to a minimal investment of US$3,000 to US$5,000.
However, it is strongly recommended that only certified thermographers who practice on a regular basis conduct the thermal scans, as the craft is a mixture of art and science. In addition to circuit panels, include switchgear, motor control centers, disconnects, transformers and switches in periodic inspections.
Breaker testing entails the extraction (“racking out”) of circuit protection devices, typically 200 amperes and larger. Current is injected into the units to measure the speed and amperage at which they trip to ensure they meet the instantaneous and steady-state ratings. It is quite an undertaking to schedule a building or portion thereof to be offline. Typically, it requires a mass effort over a weekend by a third-party and is planned months in advance.
Arc flash hazard analysis is recommended by NFPA 70E and required by OSHA (referencing NFPA 70E). Essentially, the potential energy rating is calculated for each electrical panel, disconnect, etc., which is consequently labeled with such information. The label also notes the corresponding personal protective equipment required to work on the device; this includes exercising and resetting. A short-circuit coordination study would be included with the arc flash analysis and is an extremely useful report for the breaker testing maintenance.
The frequency of these prescribed maintenance activities is dependent upon condition, operating environment and acceptable risk (impact of downtime). For a typical office building, it’s generally recommended that breakers, disconnects, etc., be exercised every six to 12 months. Infrared thermography should occur every one to two years; insurers may require a specific frequency and/or provide a discount if thermography is performed. Current injection testing ranges from triennially to quinquennially (every five years). You should also revisit arc flash hazard analysis every five years, per NFPA 70E.
Don’t Ignore the Sleeping Giant
To this point, the focus of this article has been on basic electrical distribution systems. However, given that many facilities house server and network rooms and have life safety generators, note that emergency and backup systems — such as generators, automatic transfer switches and uninterruptible power sources — have specific and more frequent maintenance requirements which are governed by the loads served and equipment type. See NFPA 110 for further guidance.
The above is not an exhaustive list of recommendations or requirements; it’s a friendly reminder not to ignore the lumbering giant that powers our facilities and the risk associated with operating and maintaining this critical system. – FMJ
- nfpa.org/codes-and-standards/all-codes-and-standards/list-of- codes-and-standards?mode=code&code=70B
John Rimer, CFM, is president of FM360 Consulting and has 20 years’ facility management experience in a variety of capacities and industries. He uses his breadth of knowledge and diverse expertise to provide a comprehensive perspective to his clients and students.
Rimer is very active in the facility management community and an avid proponent of education. As such, he is an IFMA Qualified Instructor and an approved Building Operator Certification instructor.