The Martindale PD440S is a direct replacement for the industry standard PD440. Its voltage output is matched to the VI13800, the MTL10 and MTL20 Drummond test lamps and all other 440V voltage indicators and testers.
In addition to all the benefits of the industry standard Martindale PD440 and PD690 proving units, the S models feature a tough overmoulded low profile case and come with an MG3 magnetic hanger (excluding kits). They are fast and easy to use, instantly supplying the test voltage for both high and low impedance voltage indicators, test lamps and meters.
It’s good practice to match the output voltage of the proving unit with the voltage range of the instrument to be proved. The new S and SX Series simplify matching devices as they are colour coded with Martindale voltage indicators.

Safely and simply proves the operation of voltage indicators and test lamps up to 440V
Essential for implementing effective safe isolation procedures
Tough over-moulded low profile design
Long battery life with low battery indicator
Includes MAG3 high strength magnetic hanger
Colour coded for voltage output