Q: Could an end user wear a 12″ High voltage protector over a Class 00/0 14″ rubber glove?
The difference between a 13″ Class 00/0 protector and a 12″ Class 1-4 protector is the cuff color.
A: Some companies will not allow this because they want the protector cuff cover to indicate that the glove is HV.
But there is nothing to prohibit this practice. The prohibition is having the protector too long. Higher class protectors do have ONE difference, thickness of the leather. Higher voltage gloves require the minimum thickness of the leather to be more.
For protector lengths see our NFPA 70E Low Voltage Training slide below.
If a protector is too long the flash-over distance has been compromised and the rubber insulating glove meeting ASTM D120 has been compromised in providing protection from shock.
When we do onsite NFPA 70E Compliance Electrical Safety Audits or evaluate electrical safety written programs (required by OSHA law) we look for this since it is a common misunderstanding in training or something that doesn’t fully filter into the written program. Many workers think, “longer protector gloves will protect my rubber glove better”, not thinking about the flashover issue. Makes sense when you think it out.
Update Feb. 18, 2019: New Article
Specifying Arc-Rated and Flame-Resistant Gloves, by Hugh Hoagland and Stacy Klausing