Hi-pot and megger test – Rockwell Automation MV SMC Flex Motor Controller (for Series K or later) User Manual

Page 71

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Rockwell Automation Publication 1560E-UM051F-EN-P - June 2013

61

Commissioning Procedure

Chapter 3

If the factory settings are not suitable for the application, program the module to
meet the application requirements. Contact your local Rockwell Automation
representative or the factory if assistance is required.

Hi-Pot and Megger Test

It is recommended that insulation levels be checked before energizing power
equipment. This may be done with a High Voltage AC insulation tester
(HI-POT) or a Megger. See Vacuum Contactor User Manual for suggested
HI-POT testers, and for test procedures for vacuum contactors. If using a
Megger, a 5000 volt type is recommended.

Insulation may be tested from phase to phase and phase to ground. The
recommended level for AC HI-POT testing is (2 X VLL) Volts, where VLL is the
rated line-to-line voltage of the power system. The leakage current may be
recorded for future comparison testing, and must be less than 20 mA.

If a Megger is used, it should indicate 50 k megohms or greater if it is isolated as
explained in the next paragraph. If the motor is connected, the Megger should
indicate 5 k megohms or greater.

If a 1560E is being tested, it is recommended that the input and output cables be
disconnected for each phase. If a 1562E is being tested, it is recommended that
the main contactor be in the open position, and that the output cables be
disconnected for each phase. (See points marked with an asterisk * in

Figure 36

)

This will ensure the unit is isolated from the line and the motor. The line and the
motor may be tested separately to locate problem areas. If a 1503E is being tested,
consult OEM documentation.

After completing the test, remove all semiconductor jumpers and test the devices
with a multimeter to ensure no damage has occurred from the insulation test.
Reconnect the system as it existed prior to this section. Perform the power supply
and resistance checks in the following sections.

ATTENTION: Solid-state devices can be destroyed by high voltage. Use jumper
wires between heatsinks to short out the SCRs before applying high test
voltages to the power circuit. Disconnect the white wires (L1, T1, L2, T2, L3, T3)
from the voltage sensing board and remove the plug connector. If voltage
transformers are present, remove one primary fuse from each device. On the
1503E, consult OEM documentation for location of voltage sensing board.

ATTENTION: Use caution when performing the HI-POT or Megger Test. High
voltage testing is potentially hazardous and may cause severe burns, injury or
death. Where appropriate, the case of the test equipment should be connected
to ground.

ATTENTION: Failure to reconnect all wires and cables correctly may result in
equipment damage, personal injury or death.

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