Original Version
 Rule 20.7
 
20.7    Common Neutral Systems mean those electrical 
supply distribution systems wherein the same specially grounded conductor 
is utilized as a neutral conductor of primary circuits of less than 5000 volts
and secondary circuits of 0-750 volts supplied therefrom.
 
 
Strikeout and Underline Version
 Rule 20.7
 
 20.7    Common Neutral Systems mean those electrical 
supply distribution systems wherein the same specially grounded conductor 
is utilized as a neutral conductor of primary circuits of less than 21,000
  5000 volts and secondary circuits of 0-750 volts supplied 
therefrom.
 
 
Final Version
 Rule 20.7
 
 20.7    Common Neutral Systems mean those electrical
supply distribution systems wherein the same specially grounded conductor
is utilized as a neutral conductor of primary circuits of less than 21,000
volts and secondary circuits of 0-750 volts supplied therefrom.