System Preparation 3-3 
3.2.2  Equipotential terminal 
The symbol    represents the equipotential terminal that is used for balancing the protective 
earth potentials between the system and other electrical equipment. 
1.  Be sure to connect the equipotential wire before inserting the 
power plug into the receptacle; be sure to pull out the power 
plug from the receptacle before disconnecting the 
equipotential wire; otherwise electric shock may result. 
2.  When you connect another device to this system, you should 
use the equipotential wire to connect each of equipotential 
terminals; otherwise electric shock may result. 
3.  Connect the earth cable before turning ON the system. 
Disconnect the earth cable after turning OFF the system. 
Otherwise, electric shock may result. 
4.  DO NOT connect this system to outlets with the same circuit 
breakers and fuses that control the current to devices such 
as life-support systems. If this system malfunctions and 
generates overcurrent, or when there is an instantaneous 
current at power ON, the circuit breakers and fuses of the 
building’s supply circuit may be tripped.