11-1-5  Megger Test   
 
Before performing a megger test on external circuits, be sure to disconnect all the terminals of the 
inverter and not to apply the test voltage to the inverter. Use a 500 VDC megger for a megger test. 
For a megger test on the inverter main circuit, short-circuit the terminals R/L1, S/L2, T/L3, U/T1, V/T2, 
W/T3, RB, +1, P/+2, and N/− with wires, as shown below. 
Because the insulation resistance rating of the single inverter unit is 5 M or higher, it is normal if the 
resistance is 5 M or higher. 
• 
For the inverter, do not perform a megger test on the control circuit. Perform it only on the main cir- 
cuit. 
• 
Use a tester (in a high resistance range) for a power-on test on the control circuit. Do not use a meg- 
ger or buzzer. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11-1-6  Withstand Voltage Test   
 
Do not conduct a withstand voltage test on any part of the inverter. 
Doing this test is dangerous because it may cause damage to or deterioration of the parts inside the 
inverter. 
 
 
11-1-7  Inverter/Converter Unit Test   
 
Use the following procedure to check conditions of the inverter and converter units by using a tester. 
 
 
1  Disconnect the externally connected power supply wires (R/L1, S/L2, T/L3), the motor 
connection wires (U/T1, V/T2, W/T3), and the regenerative braking resistance (P/+, RB). 
2  Prepare a tester. Use the 1  resistance measurement range.