3 Installation
3.8 Insulation testing
DC1…20… and DC1…OE1 Variable Frequency Drives
02/20 MN040059EN
www.eaton.com
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3.8 Insulation testing
The variable frequency drive of the DC1 series are tested, delivered and
require no additional testing.
If insulation testing is required in the power circuit of the PDS, you must
consider the following measures.
Testing the motor cable insulation
▶
Disconnect the motor cable from the connection terminals U, V and W of
the variable frequency drive and from the motor (U, V, W). Measure the
insulation resistance of the motor cable between the individual phase
conductors and between the phase conductor and the grounding
conductor.
The insulation resistance must be greater than 1 M
Ω
.
Testing the mains cable insulation
▶
Disconnect the power cable from the mains supply network and from
the connection terminals 1/L, L2/N and L3 of the variable frequency
drive. Measure the insulation resistance of the mains cable between the
individual phase conductors and between each phase conductor and the
protective conductor.
The insulation resistance must be greater than 1 M
Ω
.
Testing the motor insulation
▶
Disconnect the motor cable from the motor (U, V, W) and open the
bridge circuits (star or delta) in the motor terminal box.
Measure the individual motor windings’ insulation resistance. The
measurement voltage must at least match the rated operating voltage of
the motor but is not to exceed 1000 V.
The insulation resistance must be greater than 1 M
Ω
.
CAUTION
On the control signal and the connection terminals of the
variable frequency drive, no leakage resistance tests are to be
performed with an insulation tester.
CAUTION
Wait at least 5 minutes after switching the supply voltage off
before you disconnect one of the connection terminals (L1/L,
L2/N, L3, DC-, DC+, BR) of the variable frequency drive.
￫
Consider the notes from the motor manufacturer in testing the
insulation resistance.
