www.heatingandventilating.net Are you Voltage indicators
Voltage indicators should already be an integral part of your electrical safety processes. They do exactly what they say: they indicate the presence of voltage. The best voltage indicators for safe isolation should be made to BS EN 61243-3 for full compliance with the current GS38 standard. They should be engineered with safety in mind, eliminating batteries and switches that could lead to false indications and come with bright, clear displays for voltage reading, such as our own Martindale Electric VI13800 and VI15000 voltage indicators. A durable design that can take some rough handling should also be a consideration. However, even if you follow this advice and
even bearing in mind that voltage indicators are designed with inherent reliability, can you 100% guarantee that your voltage indicator is working correctly every time? It only needs to fail once for the consequences to be potentially disastrous; never forget that 16% of deaths in the workplace are linked to electricity.
A belts and braces approach
For maximum safety, it is vital to verify the performance of your voltage indicator – as important as confirming the appliance or circuit being tested is dead and there is no possibility of it becoming live while you are working. Before testing the circuit, voltage indicators should therefore be proved using a proving unit, then test the circuit, then test the voltage indicator against the proving unit once again to prove the tester is still functioning properly. The proving unit will verify the performance of the voltage indicator.
If you use a battery powered voltage indicator (which I advise against), then proving the unit is working and the battery is not flat, couldn’t be more important. Furthermore, a lack of positive indication does not always prove absence, which is why the cross-check with a proving device could quite literally be a lifesaver.
How to use a proving device
Essentially a proving unit is a portable device that serves as a voltage source designed specifically to verify that voltage indicators are working correctly. Some people still rely on testing electrical test tools, such as voltage indicators, against a live source, but this is not always a safe or convenient option. A proving device has been designed to provide a live source wherever you are working – with no need to leave the working area – and is considerably safer. Proving units are quick and easy to use. In
the case of the Martindale PD440-S 440V AC, for example, you simply place one probe of the voltage indicator under test into the left-hand socket of
Electrical safety
working on a dead circuit?
With electricity cited as the root cause of about 1,000 accidents at work each year, along with increasing financial penalties and custodial sentences for employees as well as directors, developing safe isolation processes has never been more important. Paul Wilson, UK & Ireland sales manager, Martindale Electric explains
the proving unit until it makes contact with the terminal. Then place the other probe into the right-hand terminal of the proving unit and gently press down. This will result in the high voltage indicator illuminating to show the unit under test is functioning correctly. During testing of your voltage indicator, I
recommend flexing the voltage indicator cable along its length – particularly at the entry points to the hand held elements – to confirm that the cable has not fractured. It is advisable to use a dedicated proving unit matched to the voltage indicator in order to fully test that all LEDs on all ranges of the voltage indicator are working - safeguarding against incorrect readings due to a faulty LED, for example. Furthermore, it is important not to over-prove:
a three-phase voltage indicator should be proved at 440V whereas a common 2 pole indicator with a 690V range should be proved at 690V.
Safety first
By incorporating a proving device into an electrical safety process, makes the process inherently more robust and reliable. Although a relatively simple addition to the process, when working with or near electrical systems and equipment, a proving device can significantly reduce the risk of electrical injury. There have, tragically, been many instances of injury and loss of life where personnel have been working on circuits that were believed to be dead when they were not or had been inadvertently re- energised. It is entirely possible to minimise these risks and develop safer working practices through relatively simple changes and the introduction of safe isolation procedures.
DOWNLOAD THE HVR APP NOW November 2021 31
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36
