Anitech Systems
New member
- Location
- LA, CA
We have someone that wants us to put NFPA 70E Arc Flash info on some control cabinets we made / are making.
The Enclosure is fed from a single phase 2P+G 208/240VAC, 6400W/8000VA UPS.
The Enclosure has a 40A 208/240VAC Disconnect Breaker that feeds several 480W 24VDC 20A Power Supplies.
The enclosure is labeled with 10K SCCR (in some cases 5K),
based on the branch circuit side device specifications.
The UPS manufacturer doesn't have SCCR, Bolted MVA, Transformer Impedance,
... information available for their UPS smaller than about 15KA.
A 50A Single Phase Breaker feeds the UPS input disconnect (2P+G).
The 480 to 240/208 transformer that feeds the UPS input disconnect information is not available to us,
and is considered by the end user to be out of our scope, so we don't need to know;
{... and the transformer hasn't been selected yet in most cases, by the time they want the ARC Flash info from us}.
The Shock Protection Boundary from Table 130.3C: 50 V?300 V Limited Approach Boundary 3.5ft,
Restricted Approach Boundary Avoid contact, Prohibited Approach Boundary Avoid contact seems fine.
However, as far as the information I have available, and using formula D.2(e),
with 8KVA and 6 cycle clearing time, e.g.: POWER((53*(0.008*0.125)*0.1),0.5)
I get less than 0.9in for the ARC Flash Boundary?
Providing the above information, can anyone direct us to any reference information (or even software products)
that would allow us to make any kind of meaningful e.g. NFPA 70E 130.5 / Annex D Arc Flash Hazard Analysis Calculations?
The Enclosure is fed from a single phase 2P+G 208/240VAC, 6400W/8000VA UPS.
The Enclosure has a 40A 208/240VAC Disconnect Breaker that feeds several 480W 24VDC 20A Power Supplies.
The enclosure is labeled with 10K SCCR (in some cases 5K),
based on the branch circuit side device specifications.
The UPS manufacturer doesn't have SCCR, Bolted MVA, Transformer Impedance,
... information available for their UPS smaller than about 15KA.
A 50A Single Phase Breaker feeds the UPS input disconnect (2P+G).
The 480 to 240/208 transformer that feeds the UPS input disconnect information is not available to us,
and is considered by the end user to be out of our scope, so we don't need to know;
{... and the transformer hasn't been selected yet in most cases, by the time they want the ARC Flash info from us}.
The Shock Protection Boundary from Table 130.3C: 50 V?300 V Limited Approach Boundary 3.5ft,
Restricted Approach Boundary Avoid contact, Prohibited Approach Boundary Avoid contact seems fine.
However, as far as the information I have available, and using formula D.2(e),
with 8KVA and 6 cycle clearing time, e.g.: POWER((53*(0.008*0.125)*0.1),0.5)
I get less than 0.9in for the ARC Flash Boundary?
Providing the above information, can anyone direct us to any reference information (or even software products)
that would allow us to make any kind of meaningful e.g. NFPA 70E 130.5 / Annex D Arc Flash Hazard Analysis Calculations?