• Choice of test voltages
• Direct reading display
• Unique rugged case
• Guard terminal
• Designed for user safety
• Large, custom Analog/Digital LCD
• Built-in timer
• Locking test leads for safety
• Battery indicator
• Automatic discharge of capacitance
• Voltage measurement and warning
• Tests to 500 G½
• Weather proof to IP54
• Variable test voltage in 25 V steps
• Breakdown or ‘Burn’ modes allow choice of diagnostic approach
• Shows capacitance at end of test
• Timer sets test duration for easier test control
• Tests to 5,000 G½
• Leakage current mode

Applications:

The BM11 series is designed for testing the insulation of high voltage electrical equipment and the wide voltage range also allows it to be applied to low voltage equipment.

Generators, motors, transformers, cables and switchgear all require effective maintenance and the test techniques on the Megger range give valuable diagnostic information.

‘Spot’ Insulation tests that are the most widely used, check on the general condition of electrical insulation, called up in most standards covering equipment design, testing, installation and maintenance.

Insulation suffers from gradual steady decline, as well as occasional sudden damage; the effects of dirt, grease, moisture, vibration and chemical attack can be tracked through the recording of Polarisation Index tests which remove the temperature dependence of raw Insulation Resistance measurements.

For finding more localised insulation problems, the BM25 includes both Step Voltage and Dielectric Discharge tests. Step Voltage identifies local weak spots because they respond differently as the electrical stress is increased, while the Dielectric Discharge test can show up a single bad layer in multilayer insulation. The key to Predictive maintenance is the trending of diagnostic tests and this is facilitated on the BM25 by the ability to use a PC to store results over time for trend analysis.