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| Table 130.7(C)(15)(a) Inconsistency? https://brainfiller.com/arcflashforum/viewtopic.php?f=7&t=1952 |
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| Author: | MIControl [ Tue Dec 13, 2011 1:35 am ] |
| Post subject: | Table 130.7(C)(15)(a) Inconsistency? |
We recently stepped up our observance of the rules pertaining to NFPA 70E and I observed what I see as an inconsistency in at least one of the tables. In this table the HRC is listed as well as the gear needed to perform a task. In Panelboards > 240 V and up to 600 V: Perform infrared thermography and other non-contact inspections outside the restricted approach boundary is HRC 1. The task directly below that one is: Circuit Breaker or Fused Switch operation with covers on is HRC 0. How is this possible? If I were performing the infrared thermography, I would be no where near the live circuits, but operating a circuit breaker I would be well within the restricted boundary. This seems backwards to me. Operating to me means cycle off or resetting of the breaker, correct? That would be much more "dangerous" than maintaining a safe distance using the thermal imaging equipment in the same panel. Am I completely off base on this one? Please help me understand. Thanks |
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| Author: | cbauer [ Tue Dec 13, 2011 1:34 pm ] |
| Post subject: | |
The covers have to be removed or opened in order to do thermal scanning, unless you are using the specially made IR windows, thus the higher Cat level. |
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| Author: | MIControl [ Wed Dec 14, 2011 1:32 am ] |
| Post subject: | |
I guess I have a different view on things due to our particular setup here at our facility. I work at a food manufacturing facility. Most of our main cabinets are in a wash down environment so everything is mounted behind a solid door. Our MCC panels are in a dry environment, so that is different. Resetting a breaker entails opening a cabinet door to even see that the breaker is tripped or a VFD needs to be reset. Our current policy states that we will not even have a cabinet open unless we have gloves on (we are still working out the details of high voltage gloves or just non-melting for arc flash protection). So, resetting a breaker, inside a panel that generally has 480VAC would require HRC1 gear, as a general rule. |
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