Manual

34 Rockwell Automation Publication 1512A-UM100F-EN-P - May 2013

Chapter 4 Common Installation

Hi-Pot and Megger Test

Insulation integrity should be checked before energizing medium voltage

electrical equipment. Use a high voltage AC insulation tester or a Megger for this

test. If a Megger is used, a 5000V type is recommended.

Insulation can be tested from phase to phase and from phase to ground. The

recommended level for AC Hi-Pot testing is (2 X V

) volts, where V

is the

rated line-to-line voltage of the power system. The leakage current must be less

than 20 mA. Record the result for future comparison testing.

If a Megger is used, it should indicate 50,000 M

Ω or greater if the unit is isolated

from the line and the motor. If the unit is connected to a motor, the Megger

should indicate 5000 M

Ω or greater (phase to ground).

Start-up Procedure

Contactor Inspection

See Publication 1502-UM050_-EN-P or 1502-UM052_EN-P for information on

pre-energization inspection, vacuum bottle integrity test and insulation resistance test.

Preliminary Checks

Verif y the following :

• Contactor current and voltage ratings are correct for the attached load;

• Control voltage is correct;

• Settings for protective relays;

• Heater elements (if provided) in overload relay are secure and undamaged;

• Equipment grounding;

• External power and control connections match electrical diagrams;

• All hardware is correctly reinstalled and torqued to specifications (refer

to Recommended Torque Values

on page 2 of Chapter 1);

• All barriers are replaced to correct positions;

ATTENTION: Exercise caution when performing high voltage tests on the

equipment. Failure to do so may result in electric shock causing severe burns,

injury or death.

ATTENTION: Disconnect power factor correction capacitors (if so equipped)

before performing the Hi-Pot test. Failure to do so may result in personal injury

or damage to the equipment. See Power Lockout Procedure (refer to Power

Lock-out Procedure on page 41) for information on dissipating any stored

power in the capacitors.

ATTENTION: Remove all primary fuses for the control power transformer and/

or the potential transformer. Failure to do so may cause damage to the

equipment during the Hi-Pot test.