Arc Flash Incident Energy Analysis Hidden BenefitsYou certainly have a lot to gain from performing an incident energy analysis at your facility. Identifying the equipment with high incident energies, mitigating the hazard, identifying the arc rated PPE required for any given piece of equipment are among the great safety benefits. In addition, the arc flash incident energy analysis hidden benefits you will receive can help your facility for years.
Single Line Drawings
Whoever does the assessment of your electrical distribution system will have to find out, in simple terms, what is connected to what. They will follow conductors as they connect to panelboards, circuit breakers, disconnects, control panels, etc. They will follow it all the way from your utility connection point, or points, and continue down to your equipment on the plant floor. Using software they will build a single-line or one-line diagram of your electrical distribution system. A sort of road map of your facility’s electrical system.
Chapter 2 of NFPA 70E, Article 205.1 states: A single-line diagram, where provided for the electrical system, shall be maintained in a legible condition and shall be kept current. An incident energy analysis will gill give you a set of single-line drawings. Keep them up-to-date. They will assist maintenance, engineering and contractors in doing their jobs more efficiently and safer. Insist these drawings be updated when changes are made.
Inventory Of Equipment
At the completion of the arc flash risk assessment you should have an inventory of most of your fuses. I say most of your fuses because it depends on how much of your plant is actually surveyed. It is possible that some of your equipment will not be looked at. Certainly fuses inside control panels will not all be recorded. But you should have a good look at most of them in disconnects, motor control centers, combination starters and switchgear. Ask the people doing the arc flash risk assessment specific questions concerning your study.
How To Use The Inventory
If after looking at this inventory you discover you have several fuses that are exactly the same, yet you have none of those in your store room, you might want to order some to have on hand. If a fuse blows and you don’t have one in stock this could create excessive downtime while one is brought in. Or, it could tempt someone to use a fuse that is not an exact replacement. This can cause many problems depending on what they put in. A fuse can only be replaced by a fuse that has all the same specifications as the one it is replacing.
Improper Wiring Conditions
Another unintended benefit of an arc flash risk assessment is that a knowledgable person is going to open all of your panels to collect data. In the process of data collection it is not uncommon that wiring problems become apparent. It isn’t necessarily what the data collector is there to do, and not exactly what they’re looking for but sometimes the issues are just too obvious to miss. You should ask your data collectors to inform you when they find anything like this.
Some of the crazy things they find are funny, but some could be deadly if not corrected. One I remember was a Tuna can used as a junction box. I don’t remember Tuna cans being allowed by the National Electrical Code. Another is copper tubing or copper bars being used to replace fuses. Granted, a 1/2 inch piece of copper tubbing will last much longer than a fuse, but the building might burn down because of it. Sometimes an electrical panel is opened and it is discovered that the panel is completely full of wood dust, flour, sugar, metal dust, metal shavings, or just what ever it is that the plant processes. I remember shaken data collectors calling the office to report panels full of rat nests, tarantulas, a dead squirrel and snakes. These last problems would indicate unused opening not properly covered. It shouldn’t be hard to keep a squirrel out of your electrical enclosures. They are apparently good conductors. Tarantulas might be a bit harder.
Thermal imaging cameras have advanced in the last several years to the point where Flir can turn your iPhone or Android phone into a thermal imaging camera for a couple hundred dollars. Because you are going to open all of your electrical enclosures it makes sense to incorporate as much of an infrared study into your arc flash risk assessment as you can. The data collection will be done while the facility is in operation with equipment running. It makes sense to shoot the cabinet to see if you have issues.
It is great you are having an arc flash risk assessment done to improve the general electrical safety of your facility. The arc flash incident energy analysis hidden benefits are substantial and can impact electrical safety. To get the best value out of your study take advantage of these hidden benefits to the best of your ability.
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