Work is being performed on a 208-volt panelboard supplied by a molded-case circuit breaker that has not been maintained in over 10 years. The available fault current at the panelboard is 10 kiloamps. What level of PPE is to be worn based on the PPE Category method?

Work is being performed on a 208-volt panelboard supplied by a molded-case circuit breaker that has not been maintained in over 10 years. The available fault current at the panelboard is 10 kiloamps. What level of PPE is to be worn based on the PPE Category method?

• A. PPE Category cannot be determined
• B. PPE Category 1
• C. PPE Category 2
• D. PPE Category 3

Answer: (B)

PPE category method uses system voltage and the available fault current to estimate arc flash energy at the worker’s usual working distance, then maps that energy to a protective category. For a low-voltage system like 208 V, even with a fairly high fault current of 10 kA, the estimated incident energy at the standard working distance is low enough to fall into Category 1. That category requires the lowest level of arc-rated PPE (and basic eye/face protection). The fact that the breaker hasn’t been maintained for over 10 years doesn’t change the category determination given the stated fault current; it’s a separate safety concern about equipment condition and reliability. If the fault current or voltage were higher, a higher category would be required.

PPE category method uses system voltage and the available fault current to estimate arc flash energy at the worker’s usual working distance, then maps that energy to a protective category. For a low-voltage system like 208 V, even with a fairly high fault current of 10 kA, the estimated incident energy at the standard working distance is low enough to fall into Category 1. That category requires the lowest level of arc-rated PPE (and basic eye/face protection).

The fact that the breaker hasn’t been maintained for over 10 years doesn’t change the category determination given the stated fault current; it’s a separate safety concern about equipment condition and reliability. If the fault current or voltage were higher, a higher category would be required.