–  Ensure  that  another  person,  familiar  with  the 
power-off  controls,  is  near  you. 
 
Attention:  Another  person  must  be  there  to  switch 
off  the  power,  if  necessary. 
–  Use  only  one  hand  when  working  with  powered-on 
electrical  equipment;  keep  the  other  hand  in  your 
pocket  or  behind  your  back. 
 
Attention:  An  electrical  shock  can  occur  only  when 
there  is  a  complete  circuit.  By  observing  the  above 
rule,  you  may  prevent  a  current  from  passing  through 
your  body. 
–  When  using  testers,  set  the  controls  correctly  and 
use  the  approved  probe  leads  and  accessories  for 
that  tester. 
–  Stand  on  suitable  rubber  mats  (obtained  locally,  if 
necessary)  to  insulate  you  from  grounds  such  as 
metal  floor  strips  and  machine  frames.
Observe  the  special  safety  precautions  when  you  work 
with  very  high  voltages;  Instructions  for  these 
precautions  are  in  the  safety  sections  of  maintenance 
information.  Use  extreme  care  when  measuring  high 
voltages. 
v  Regularly  inspect  and  maintain  your  electrical  hand  tools 
for  safe  operational  condition. 
v  Do  not  use  worn  or  broken  tools  and  testers. 
v  Never  assume  that  power  has  been  disconnected  from 
a  circuit.  First,  check  that  it  has  been  powered  off. 
v  Always  look  carefully  for  possible  hazards  in  your  work 
area.  Examples  of  these  hazards  are  moist  floors, 
nongrounded  power  extension  cables,  power  surges, 
and  missing  safety  grounds. 
v  Do  not  touch  live  electrical  circuits  with  the  reflective 
surface  of  a  plastic  dental  mirror.  The  surface  is 
conductive;  such  touching  can  cause  personal  injury  and 
machine  damage. 
v  Do  not  service  the  following  parts  with  the  power  on 
when  they  are  removed  from  their  normal  operating 
places  in  a  machine: 
–  Power  supply  units 
–  Pumps 
–  Blowers  and  fans 
–  Motor  generators
and
  similar  units.  (This  practice  ensures  correct 
grounding  of  the  units.) 
v  If  an  electrical  accident  occurs: 
–  Use  caution;  do  not  become  a  victim  yourself. 
–  Switch  off  power. 
–  Send  another  person  to  get  medical  aid.
Safety  information  
18  R50/R50p,  R51  Series