TM 5-3810-306-10 Obey  the  following  rules  at  all  times,  whether  power  is cut off or not. Move  the  crane  away  from  power  sources.  Ensure  that no   part   of   the   crane   or   load   comes   closer   than   the minimum clearances allowed below. Get assurance that power has been turned OFF. IMPORTANT  -  Always  consider  wire  rope,  hoist  cable, pendant cables, tag lines, etc. as electrical conductors. EXERCISE    EXTREME    CAUTION    AND    PRUDENT JUDGEMENT WHENEVER ELECTROCUTION HAZARDS EXIST - OPERATE SLOWLY AND CAUTIOUSLY. Comply   with   all   federal,   state,   and   local   laws   and regulations. Remember  you  do  not  have  to  touch  a  power  line  or power   source   to   become   electrocuted.   Electricity   can jump from the power line into the crane. "Low" voltages can also be dangerous. Keep  all  parts  of  crane  (ropes,  hookblock  and  load)  at least: Power Source Min Clearance Under 50 KV - 10 FEET 69 KV - 12 FEET 115-161 KV - 15 FEET 230-285 KV - 20 FEET 345 KV - 25 FEET 500 KV - 35 FEET Whenever  a  load,  wire  rope,  boom  or  any  Portion  of  a crane contacts or approaches too closely to an electrical power source, everyone in, on and around the crane can be seriously injured or killed! THE ONLY SAFE WAY TO OPERATE A CRANE IS TO STAY AWAY FROM ELECTRICAL SOURCES! Appoint   a   signalperson,   equipped   with   a   loud   signal whistle or horn and voice communication equipment, to warn  you  when  any  part  of  the  crane  or  load  is  near  a power source.  This person should have no other duties while the crane is working. Warn   all   personnel   of   danger.      Keep   unnecessary personnel away from the working area. Permit no one to lean against or touch the crane.  Permit no one including sling men or load handlers to hold load, lines or rigging gear. Even  if  you  are  not  affected  by  an  electrical  contact, others in the area may become seriously injured or killed. The  use  of  boom  guards,  proximity  devices,  insulated hooks,  links  or  mechanical  limit   stops   do   not   assure safety. Even if codes or regulations require use of such devices,  failure  to  follow  rules  listed  here  may  result  in serious injury or death. You should be aware of some of the limitations of devices. Boom   cage/guards   afford   limited   protection   from electrocution.  They  are  designed  to  cover  only  boom- nose/point     and     a     portion     of     the boom. Boom cages/guards    are    limited    by    their    physical    lengths, insulating  abilities  and  operating  conditions  (e.g.,  dust, dirt, moisture, etc.). Insulating   links   installed   into   the   load   line   afford limited protection for those handling the load. Links have limited  lifting,  insulating  and  other  properties  that  affect their   performance.   Moisture,   dust,   dirt,   oils,   etc.   can cause   a   line   to   conduct   electricity.      Due    to    their capacity/ratings,  some  links  are  not  effective  for  large cranes and/or high voltages/currents. The only protection afforded by a link is that which is obtained    below    the    link    --    electrically    downstream, provided   the   link   has   been   kept   clean   and   free   of contamination  and  is  tested  prior  to  use  for   its   non- conducting capability. 2-38