Figure 10-1. Process for the analysis of circuit hazards

DOE-HDBK-1092-98

Though there is a low probability of electric shock at voltages less than 50 V (See Figure 10-1), there

is a hazard due to arcing and heating in case of an accidental fault. For example, a tool could drop

onto the terminals and initiate an arc, causing severe burns.

Analyze circuit

for hazards

Yes

Short-circuit

current >5ma

Yes

Energy

>10 J

Protect against contact

(shock hazard) per

29CFR 1910.331-335

Short-circuit

Yes

current >0.5ma

Yes

Energy

>0.25 J

Protect against

secondary

Work is not

hazards

hazardous

CIRCUIT HAZARDS

Figure 10-1. Process for the analysis of circuit hazards.

10.8.2.2

DESIGN AND CONSTRUCTION

A circuit operating at 50 V or less shall be treated as a hazardous circuit if the power in it can create

electrical shocks, burns, or an explosion due to electric arcs. Inductive circuits may create high-

voltage hazards when interrupted. Observe all of the following rules for such circuits:

10-6