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| Current Limiting Devices and Incident Energy Reduction https://brainfiller.com/arcflashforum/viewtopic.php?f=33&t=3425 |
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| Author: | Jim Phillips (brainfiller) [ Sun Aug 24, 2014 5:24 pm ] |
| Post subject: | Current Limiting Devices and Incident Energy Reduction |
Properly applied current limiting devices such as fuses and circuit breakers can greatly reduce the incident energy. Here is this week's question: Does your company/clients use any current limiting devices? Yes No |
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| Author: | C. Marsh [ Tue Aug 26, 2014 9:42 am ] |
| Post subject: | Re: Current Limiting Devices and Incident Energy Reduction |
We use almost all circuit breakers (non current limiting) except for a few individual disconnect switches which all have current limiting fuses. |
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| Author: | Jim Phillips (brainfiller) [ Tue Aug 26, 2014 11:47 am ] |
| Post subject: | Re: Current Limiting Devices and Incident Energy Reduction |
Just curious - I wonder if anyone has a facility/client that is all (almost all) fuses. It seems fuses are often used in addition to breakers rather than instead of breakers. Comments/Thoughts? |
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| Author: | PaulEngr [ Tue Aug 26, 2014 7:23 pm ] |
| Post subject: | Re: Current Limiting Devices and Incident Energy Reduction |
I have seen both. There is a belief that breakers have a lower cost of ownership. But this misses the preventive maintenance cost. Even without current limiting (which can also paradoxically raise incident energy), its hard to beat the under 1 cycle trip time of a fuse. It is trivially easy to achieve type 2 (no damage) starter ratings as well. On the other hand, it is so much easier to do a lot of very sophisticated things with a breaker and the coordination is much easier. I cannot for instance alarm or trip on ground fault with a fuse unless the ground fault current is severe. |
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| Author: | Voltrael [ Wed Aug 27, 2014 5:42 am ] |
| Post subject: | Re: Current Limiting Devices and Incident Energy Reduction |
Jim Phillips (brainfiller) wrote: Just curious - I wonder if anyone has a facility/client that is all (almost all) fuses. It seems fuses are often used in addition to breakers rather than instead of breakers. Comments/Thoughts? We have distribution breakers. All (95%+) of our motor control center starters and feeders are fused. |
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| Author: | 321Liftoff [ Tue Sep 02, 2014 8:22 am ] |
| Post subject: | Re: Current Limiting Devices and Incident Energy Reduction |
Don’t we all use them (CB's/Fuses)? We (KSC) primarily rely on CB's. Maybe a better question is, are they accounted for in our arc flash studies as the coordination studies are conducted. Seriously for MV work in man holes we realized grounding resistors at our HV-MV Substations can make a substantial difference in minimizing the available Incident Energies. Though we're a local tight night area, and this application might be difficult for utilities serving municipalities. One neat option I ran into includes the following (speaking of current limiters): http://www.gwelec.com/current-limiting- ... -l-en.html FWIW, Liftoff |
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