High voltage and shock hazard warning signs should be installed on or in the vicinity of equipment or accessories having exposed conductors at potentials of 30 volts (root mean square or dc) or above. Exposed conductors include those from which personnel may receive a shock by physical contact or by voltage arc over. The signs should be posted so that they are obvious and can be clearly read by personnel entering the area.

Compartments or walk-in enclosures containing equipment with exposed conductors presenting shock hazards in excess of 500 volts (root mean square or dc) should have a "Danger High Voltage" sign (fig. 3-6) posted conspicuously within each entrance.

Compartments or walk-in enclosures containing equipment with exposed conductors presenting shock hazards between 30 volts (RMS or dc) and 500 volts (RMS or dc) should have either a "Danger High Voltage" sign or a "Danger Shock Hazard" sign posted conspicuously within each entrance.

Figure 3-6.-High voltage warning sign.

STACK GAS WARNING SIGN

A warning sign to alert personnel working aloft near smoke pipe (stack) gases is shown in figure 3-7. One sign should be mounted near the bottom of each access ladder leading aloft. Another sign should be located at the top of each ladder but mounted on the base of the antenna pedestal.