Megger MPU690 Operating Manual

MPU690 Proving Unit

User Guide

Introduction

The MPU690 Proving Unit safely generates high voltages to energise
2 pole voltage testers thus allowing verification of their correct
operation. The unit will also test voltage testers that use a pygmy
lamp.

Features include automatic power on when voltage tester probes are
inserted into the output terminals, 50Hz test voltage to simulate AC
mains supply and a magnetic back to the case.

Instructions

To activate the MPU690 firstly insert the voltage tester flying lead
probe into the right hand terminal followed by the voltage tester fixed
probe into the left hand terminal.

Gently apply and maintain pressure to the left hand probe to activate
the internal power switch. The test voltage is transmitted to the
voltage tester.

The test voltage LEDs will automatically ramp up to 690 volts and then
slowly ramp back down 690 V - 400 V - 230 V - 100 V - 50 V - OFF (to
re-test slightly lift the left-hand probe and re-apply the pressure).

The advantages of the auto test function are:

1. Individual voltages are applied at five key voltage test
points with significant battery savings as power is
automatically switched off when the test is completed.

2. Once the voltage tester has been proved to be correctly
functioning you may carry out testing circuits.

It is recommended that a voltage tester be verified regularly.

Safety Warnings – Risk of electric shock

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Safety Warnings must be read and understood before instrument is
used. As this unit generates voltages up to 690 volts caution should
be exercised, hands should remain behind guards of applied voltage
detectors.

■ Never connect to installation wiring.

■ Only voltage testers should be connected to the proving unit.

■ Never insert wire, nails or screwdrivers into either terminal.

■ Do not force objects into the left hand terminal to enable

permanent operation.

■ Ensure the unit is free from moisture, grease and dust;

clean unit with a soft dry cloth only.

■ Do not use if there is any damage to the MPU690.

■ The battery cover must be in place whilst conducting tests.

Note: This instrument must only be used by suitably trained
and competent persons.