Arc-Resistant Switchgear Construction or Arc-Detection Devices?

In Powell Tech Brief #51, I discussed the arc-resistant construction which is now available in Powell's PowlVac® metal-clad switchgear. As noted in the PTB, arc-resistant switchgear must resist two phenomena - increased internal pressure and burnthrough. These two phenomena operate in two different time frames. Burnthrough is a relatively long-time event. The test to prove resistance to burnthrough is of one second duration.