Multifunction Tester Buyers Guide

With over 20 different multifunction tester models available in the UK, choosing the correct one can seem like a daunting task.

If you’re shopping for a new tester, various manufacturer’s comparison charts can be big help deciphering what features a specific model offers over another within their respective ranges, but they can also raise further questions in comparison with other manufacturer’s models, and so you may find yourself going around in circles.

 

Contents


Where To Start?

A good starting point is to consider what sort of installations the tester will be used for testing as the answer often narrows down the choice to a few models.

For example, if you’re a Part P domestic electrician, you most likely won’t want to spend extra hard-earned cash on features such as 400V line testing, phase rotation industrial type RCD testing.

On the flipside, if you’re installing three phase equipment and testing multi-phase distribution boards in a commercial/industrial environment, you’ll become stuck with a tester that isn’t suitable for three-phase installation work.

What tests will I need to conduct?

Let’s take a closer look at the test features you’ll likely need. Below is a table of the tests required by BS7671 (BS7671:2018 at time of writing), and the test feature you’d need to select upon a multifunction tester to conduct the test:

BS7671 Sequence of tests Test feature required Further considerations
Continuity of protective conductors, including main and supplementary bonding 200mA continuity test A lower current 15mA continuity test for checking inductive loads such as motor windings
Continuity of ring final circuit conductors 200mA continuity test
Insulation resistance (250V tests for SELV/PELV, 500V for verification of electrical separation and 500V/1000V for measuring insulation resistance of floors and walls) 250V, 500V and 1000V insulation resistance tests Lower voltage (50V/100V) test options for voltage sensitive equipment
Polarity 200mA continuity test N/A
Protection by ADS Option: Earth loop impedance test, RCD test or earth resistance test N/A
Earth electrode resistance Option: Earth resistance test, earth resistance clamp, or earth loop test Stakeless clamp options where disconnection of earth electrodes is not possible
Earth fault loop impedance Earth loop test All MFTs now offer anti-trip loop testing. However, consider 3 phase line to line impedance testing, high resolution loop impedance options (from 0.001 ohms), automatic pass/fail visual indicators based on BS7671 maximum disconnection times, and models that negate RCD uplift to produce a more accurate measurement
Prospective fault current Earth loop test N/A
RCD tests RCD tests Consider whether you need a tester capable of testing specific RCD types; for example, 6mA DC current RCDs for EV chargers
Phase sequence Phase rotation or phase sequence test N/A
Voltage drop verification Voltage test N/A

 

We can conclude that BS7671 requires a total number of 7 tests to be performed to check an electrical installation. However, depending on your scope of testing, it’s very likely that you may only require 5 of the 7 test options:

  • For most installations, a loop test can be used to check earth electrodes rather than using a dedicated earth electrode test option that requires test spikes and long test leads
  • You won’t require your new tester to carry out phase sequence/phase rotation tests if you’re a domestic electrician testing single phase circuits only

It’s helpful to categorise the various MFTs available on the market into 3 groups: Domestic/Part P, commercial and industrial.


Domestic/Part P Multifunction Testers

The multifunction testers that fall into this category are suitable for domestic installers and Part P contractors checking and certifying single phase, 230V, electrical installations. Whether you’re adding a socket to an existing circuit and need to issue a MEIWC to verify your work, or you may have been asked to issue multiple EICRs by a landlord who owns an array of properties, these models will offer you all the test options you’ll need.

Test feature Kewtech KT63DL Dilog DL9110 Megger MFT1711
Continuity 200mA 200mA 200mA
Insulation Resistance 250V, 500V, 1000V 250V, 500V 250V, 500V, 1000V
Loop Test Anti-trip Anti-trip Anti-trip
Earth Electrode Test No No No
PFC/PSC Yes Yes Yes
RCD AC, ACS, A & AS
Auto-test on 30mA RCD
Ramp test
AC, ACS, A & AS
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A & AS
Auto-test on all available instrument RCD ratings
Ramp test
Phase Rotation No No No
Other features Hands-free operation
PAT Testing with optional PAT Adaptor 1
UK’s largest colour LCD display 2-wire (Line to CPC) anti-trip loop test
Warranty 2 years 2 years, option to extend to 3 years with manufacturer 3 years, register with manufacturer
Price £549.00 £439.00 £694.00

Commercial Multifunction Testers

The most ‘crowded’ section of the market, with plenty of options available. The testers that fall into this category offer all the test functions that a domestic/Part P tester will offer, but in addition, tests such as 415V 3 phase loop testing, insulation test voltages starting at 50/100V, phase rotation testing, earth electrode testing and more extensive RCD testing making them suitable for applications such as shop-fitting, office maintenance and light industrial installation. It’s important to notice that models that fall into the commercial category start to offer the specific 6mA DC RCD test required to test EVSE equipment, too, which we expect to heavily impact the buyer’s choice of multifunction tester:

Test feature Metrel MI3125 Martindale ET4000 Dilog DL9118 Metrel MI3125BT Metrel MI3100S Martindale ET4500 Metrel MI3100SE Kewtech KT63 Plus Kewtech KT65DL Megger MFT1721
Continuity 15mA, 200mA 8.5mA, 200mA 200mA 15mA, 200mA 15mA, 200mA 15mA, 200mA 8.5mA, 200mA 200mA 200mA 15mA, 200mA
Insulation Resistance 50V, 100V, 250V, 500V, 1000V 50V, 100V, 250V, 500V, 1000V 250V, 500V, 1000V 50V, 100V, 250V, 500V, 1000V 50V, 100V, 250V, 500V, 1000V 50V, 100V, 250V, 500V, 1000V 50V, 100V, 250V, 500V, 1000V 250V, 500V, 1000V 250V, 500V, 1000V 100V, 250V, 500V, 1000V
Loop Test Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase, 0.001 resolution Anti-trip, 3 phase, 0.001 resolution Anti-trip, 3 phase
Earth Electrode Test No No No Option Option Option Option No Option No
PFC/PSC Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
RCD AC, ACS, A, AS & F
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS & F
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS, F, B & B+
Auto-test on all available instrument RCD ratings
Ramp test
6mA DC test for EVSE
AC, ACS, A, AS & F
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS & F
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS & F
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS, & B
Auto-test on all available instrument RCD ratings
Ramp test
Phase Rotation Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Other features Visual pass/fail loop test indicator
Rechargeable
Remote test probe included
Visual pass/fail loop test indicator
Rechargeable
UK’s largest colour LCD display 6mA DC RCD test for EVSE testing
Downloadable
Visual pass/fail loop test indicator
Rechargeable
Voltage monitoring capability
Downloadable
Visual pass/fail loop test indicator
Rechargeable
Downloadable
Remote test probe included
Visual pass/fail loop test indicator
Rechargeable
Downloadable
Visual pass/fail loop test indicator
Rechargeable
Slimline form
PAT Testing with optional PAT Adaptor 1
Remote test probe included
Downloadable, visual pass/fail loop test indicator
PAT Testing with optional PAT Adaptor 1
Remote test probe included
Rechargeable
Warranty 2 years 2 years 2 years, option to extend to 3 years with manufacturer 2 years 2 years 2 years 2 years 2 years 2 years 3 years, register with manufacturer
Price £480.00 £479.00 £499.00 £570.00 £575.00 £615.00 £619.00 £725.00 £799.00 £940.00

Industrial Multifunction Testers

The multifunction testers in this category are suitable for domestic/Part P, commercial and more dedicated testing industrial type applications, including utility earth testing, specialist medical installations, diagnostic testing and even monitoring power consumption/detecting harmonics problems. In addition, most models in this category offer the specific 6mA DC RCD test required for testing the type of RCD required in EVSE charging equipment:

Test feature Metrel MI3102 BT Metrel MI3152 XC Kewtech KT66DL Megger MFT1741+ Megger MFT-X1 Metrel MI3155 XD
Continuity 15mA, 200mA 8.5mA, 200mA 15mA, 200mA 15mA, 200mA 10mA, 200mA 8.5mA, 200mA
Insulation Resistance 50V, 100V, 250V, 500V, 1000V 50V, 100V, 250V, 500V, 1000V 100V, 250V, 500V, 1000V 100V, 250V, 500V, 1000V 50V to 1000V 50V, 100V, 250V, 500V, 1000V, 2500V
Loop Test Anti-trip, 3 phase Anti-trip, 3 phase Anti-trip, 3 phase, 0.001 resolution Anti-trip, 3 phase, confidence meter Anti-trip, 3 phase Anti-trip, 3 phase
Earth Electrode Test Option, including stakeless options Option, including stakeless options Option Option, including stakeless options Option, including stakeless options Option, including stakeless options
PFC/PSC Yes Yes Yes Yes Yes Yes
RCD AC, ACS, A, AS, F, B & B+
Auto-test on all available instrument RCD ratings
Ramp test
AC, ACS, A, AS, F, B & B+
Auto-test on all available instrument RCD ratings
Ramp test
6mA DC test for EVSE
AC, ACS, A, AS, F & B
Auto-test on all available instrument RCD ratings
Ramp test
6mA DC test for EVSE
AC, ACS, A, AS, & B
Auto-test on all available instrument RCD ratings
Ramp test
6mA DC test for EVSE
AC, ACS, A, AS, B, & BS
Auto-test on all available instrument RCD ratings
Ramp test
6mA DC test for EVSE
AC, ACS, A, AS, F, B & B+
Auto-test on all available instrument RCD ratings
Ramp test
6mA DC test for EVSE
Phase Rotation Yes Yes Yes Yes Yes Yes
Other features Power measurements and harmonics analysis
IMD/First fault leakage current test for medical circuitry
Visual pass/fail loop test indicator
Automatic test sequencing
Downloadable
Rechargeable
Touch-colour screen user interface
Power measurements and harmonics analysis
IMD/First fault leakage current test for medical circuitry
Visual pass/fail loop test indicator
Automatic test sequencing
Downloadable options
Rechargeable
PI/DAR diagnostic tests
Visual pass/fail loop test indicator
PAT Testing with optional PAT Adaptor 1
Remote probe included
Downloadable
Colour screen
Remote test probe included
Confidence meter when loop testing; provides accuracy indication as to reliability of the measured loop impedance value
Rechargeable
Downloadable

Remote test probe included Confidence meter when loop testing; provides accuracy indication as to reliability of the measured loop impedance value                    Rechargeable                            Downloadable

Touch-colour screen user interface
PI/DAR diagnostic tests
Power measurements and harmonics analysis
IMD/First fault leakage current test for medical circuitry
Visual pass/fail loop test indicator
Automatic test sequencing
Downloadable options
Rechargeable
Warranty 2 years 2 years 2 years 3 years, register with manufacturer 3 years, register with manufacturer 2 years
Price £925.00 From £1089.00 £1089.00 £1210.00 £1349.00 From £1955.00

What Else Should I Consider?

In addition to choosing a model that comes at the correct price and specification for the scope of electrical testing work that you’ll be conducting, it also pays to consider testing features that aren’t mandatory; features to make your job easier onsite:

  • Remote test probes – many models include a test probe that features a button on the shaft of the probe. When pressed, this button has the same effect as pressing the test button on the instrument itself. Imagine you’re carrying out a loop test at a light fitting from on top of a ladder; having to hold all three test probes with one hand so that you can access the instrument test button can be challenging, hence when using a remote probe, you’ll be able to free up one hand to make doing the test a lot easier
  • Visual pass/fail indicators – a few manufacturers offer this option when conducting a loop test. Basically, these models have all the maximum disconnection times and impedances for different fuse types included in the firmware of the tester. Simply select the device that is protecting the circuit under test (eg BSEN 60898, B, 32A) and your test result will show as acceptable or not. If the values in BS7671 ever change, the firmware can be updated to keep the instrument up to date
  • Automatic test sequences – programme the MFT with custom test sequences for automatic succession to the next test function once the previous has been conducted. Very useful for carrying out quick, successive EICRs without having to select the test function after each test
  • Downloadable – some models include a memory that allows for downloading test results and issuing certificates electronically. This takes the time out of handwriting each certificate and recording test results on site
  • Rechargeable – recharge the batteries in-situ; simply plug a mains charger into the MFT to recharge the batteries
  • Price – of course budgeting is paramount. However, investing into a new tester that falls short of the ideal specification that you require can stop you earning more in terms of what and how you’ll be able to test. For example, if you set a firm budget at £400, you’ll fall short of the tests required to successfully install, test, and maintain EVSE equipment that an additional £100 would have made possible – a market that is currently booming. Likewise, it wouldn’t make sense to invest into a £1500+ model if all you’ll ever need to test are occasional single-phase circuits. 

Further Information

For any additional support or information concerning multifunction testers, please drop us a line on 0113 248 99 66 (option 1) and our advisors will be happy to help.