Honeywell SmartVFD HVAC2 Applications Manual page 39

Cable and motor insulation
checks
These checks can be performed as follows if
motor or cable insulations are suspected to be
faulty.
1. Motor cable insulation checks
Disconnect the motor cable from terminals
U / T1, V / T2 and W / T3 of the frequency
converter and from the motor. Measure the
insulation resistance of the motor cable
between each phase conductor as well as
between each phase conductor and the pro-
tective ground conductor.
The insulation resistance must be >1
MOhm.
2. Mains cable insulation checks
Disconnect the mains cable from terminals
L1, L2 / N and L3 of the frequency con-
verter and from the mains. Measure the
insulation resistance of the mains cable
between each phase conductor as well as
between each phase conductor and the pro-
tective ground conductor. The insulation
resistance must be >1 MOhm.
3. Motor insulation checks
Disconnect the motor cable from the motor
and open the bridging connections in the
motor connection box. Measure the insula-
tion resistance of each motor winding. The
measurement voltage must equal at least
the motor nominal voltage but not exceed
1000 V. The insulation resistance must be
>1 MOhm.
39 31-00108—07