jischr
Member
- Location
- St. Louis, MO, USA
We have a 480V, 1600 amp breaker that gets racked out when work needs to be performed. It is racked out with a closed front. The act of racking introduces an arc flash/blast hazard.
The switch feeding the breaker is 4160V, 1200 amp, that is not capable of being locked out. So racking out the 4160 switch is the equivalent of lockout.
The debate is that racking the 4160V switch introduces a greater hazard so we are justified in racking out the 480V breaker while the buss is live. As a safety engineer my counter is that the 4160V switch should be be thrown and taggged out; and a person could be station at the switch to prevent actuation until the person working on the breaker is standing in front of them and throws it.
The basic question is, does racking a breaker constitute work with an electrical hazard that requires de-energization to comply with 70E and 1910.333, or is it no different than throwing any other switch at the equivalent voltage?
Thanks
The switch feeding the breaker is 4160V, 1200 amp, that is not capable of being locked out. So racking out the 4160 switch is the equivalent of lockout.
The debate is that racking the 4160V switch introduces a greater hazard so we are justified in racking out the 480V breaker while the buss is live. As a safety engineer my counter is that the 4160V switch should be be thrown and taggged out; and a person could be station at the switch to prevent actuation until the person working on the breaker is standing in front of them and throws it.
The basic question is, does racking a breaker constitute work with an electrical hazard that requires de-energization to comply with 70E and 1910.333, or is it no different than throwing any other switch at the equivalent voltage?
Thanks