January 2015 saw the introduction of the 3rd amendment to the 17th Edition wiring regulations. Part of the 3rd amendment sees new limits introduced for earth loop testing. To coincide with this change, Martindale Electric launched two new multifunction testers: the ET4000 and the ET4500.
One big advantage these testers have is the new pass limits are built-in, making it easier to test to the new regulations. We look at how these new testers stack up against the brands that have already established themselves in this market and what the benefits are for you.
Out of the box, the new testers certainly look the part. Utilising the classic “binocular” style design, the tester certainly has the build quality. Anyone who is familiar with the Metrel brand will recognise the styling, indeed the tester is manufactured by Metrel for Martindale, however there are some key features that are specific to the Martindale unit.
Firstly, the Martindale tester takes a standard 4mm banana lead, as opposed to a dedicated connector block and the supplied Martindale leadset includes a slimline remote start probe. This makes it easier to get a wide range of replacement leads in a hurry. Secondly, changes have been made to the firmware, making it more applicable to the UK.
They are both supplied with a soft carry case and can be used either in the case or not. A neck strap is also included which has a great quick release feature.
Both testers come with a built-in battery charger, but only the ET4500 is supplied with rechargeable batteries as standard. There is also an option to purchase an in car charger.
Ease of Use
When it comes to buying a new tester, one of the important factors is how easy it is to use. A rotary dial is used to select the desired test. Once a test is selected, the test parameters are set via the menu options. This is a reasonably easy process, however a condensed instruction manual is included which will familiarise you with the functionality.
What 17th Edition Tests Do They Carry Out?
Not all multifunction testers carry out the same tests. Some of the cheaper options on the market are really only designed for domestic installations, lacking the capability to test larger industrial installs.
With the Martindale testers, you get a full range of tests, even on the entry level model.
- Insulation resistance testing at 50, 100, 250, 500 & 1000V
- 200mA & 8.5mA continuity tests
- AC, A, F, & S Type RCD testing supported
- RCD trip time, ramp & auto testing
- 10mA, 30mA, 100mA, 300mA, 500mA & 1000mA RCD test currents
- Non trip & high current loop testing
- True RMS voltage measurement
- Frequency measurement
- Phase rotation
- Earth resistance test (ET4500 only)
This list of tests really makes the ET4000 series stand out. Consider the fact it will carry out a true RMS voltage measurement. This is a feature that is only available on the high end testers from manufacturers such as Megger, however it comes as standard with the Martindale. True RMS measurements are more accurate, ensuring measurement of voltage levels really are within the new Cmin limits defined in amendment 3.
On the Megger 1730 and Fluke 1654B counterparts, you will find a DC (B Type) RCD test, however as not many people would use this, we don’t see it as a downside. Possibly of greater value is the ability of the Martindale instruments to test the new type F RCDs, which provide protection against mixed frequency residual currents from single phase loads such as washing machines and pumps in residential and commercial buildings.
Graphical Help screens are included, explaining how the tester should be connected. This makes it ideal for apprentices and those starting out, as well as training centres and colleges.
Loop Test Accuracy
Non-trip earth loop test results can vary a lot between testers. Each manufacturer has their own way of making the measurement. Different approaches to the way the test is carried out influence the end result, so how does the Martindale compare?
The accuracy of the non-trip loop test is +/- (5 % of reading + 10 digits). With an applied value of 1Ω, the result could be anywhere between 0.85Ω to 1.15Ω and still be considered within specification. All testers are susceptible to noise on the line and the Megger units even have this as an unknown variable when quoting the accuracy. If there is too much noise to carry out the test, your only option may be to use a high current loop test, which is also more accurate.
During testing in our service department, both the ET4000 & ET4500 performed well, giving accurate and repeatable results.
What About the Test Leads?
Test leads can often be overlooked when purchasing a new tester. Often though, they are the most replaced item. Some multifunction testers require dedicated plugs or connectors. This is not the case with the ET4000 series. The tester takes a standard 4mm banana connection and is supplied with a universal lead set, remote test probe & 13A mains lead.
Using this common design means it will be easy to get a new set of leads in a hurry, as most wholesalers will keep something in stock. The lead set supplied consists of a 4mm banana to banana with interchangeable probes and crocodile clips. This design makes it easy to connect to R2 socket adaptors and calibration checkboxes.
Safety first!
Not all testers are the same and not all testers carry the same safety ratings. Whereas some cheaper testers are only CAT III rated, the new Martindale is both CAT III & CAT IV.
Because both testers come with a built-in battery charger, a sliding cover has been added so the tester cannot be charged and used to test at the same time.
User upgradeable firmware
Ever had to send your tester back to the manufacturer because something wasn’t quite working correctly due to a bug in the firmware? When this happens, you could be without your tester for a week, sometimes longer.
With the Martindale testers, you can update the firmware yourself, so any changes to the testing regulations or bug fixes can be applied without the need to return it. Firmware updates are available regardless of whether the tester has download capability or not.
What do you get with the downloading version?
The top model ET4500 will store up to 1800 test results and downloads to software which is included free with the tester. The software allows you to create plain paper test certificates only, as well as maintain the test history for all your customers.
This model will also perform a 2 or 3 wire earth resistance check. The earth spike kit is an optional extra, but at a cost of around £80 + VAT it’s not a huge expense.
Finally, the ET4500 is supplied with low discharge rechargeable batteries as standard and a plug-in mains charger. The tester has a built-in battery charger, so no need to remove the batteries to charge. The low discharge batteries retain their charge even when the tester hasn’t been used for a long time.
Value for money?
These new testers are available at a very favourable price. When compared to the Megger & Fluke counterparts, your money really will go further. The market price of the ET4000 is around £480.00 + VAT, with the ET4500 at around £570.00 + VAT.
Martindale is a trusted UK brand, with a strong range of quality test equipment and the new ET4000 series really complements this range. Although manufactured in Europe, all service, support and repairs are UK based. The testers are backed with a 2 year warranty and all units are supplied with manufacturers’ calibration test certificates.
For further details as to how these testers compare to those currently on the market, download our full product comparison.
