megger-mft1720

Megger MFT1720 Multifunction Tester

The Megger MFT1720 is one of the most popular testers within the range. Domestic installers wanting to protect themselves against future three-phase installation work will consider the MFT1720, as will any engineer conducting EICR’s or undertaking volumes of domestic and commercial installation work.

As well as the 200mA test offered by the Megger MFT1710, the MFT1720 also offers a 15mA continuity test. In general, the 15mA function will see the tester serving as an ordinary multi-meter outputting a low-test current suitable for testing inductive components such as motor windings and coiled cables.

The Megger MFT1720 offers a 1000V insulation resistance in addition to 250V and 500V. This opens up a range of testing applications such as motor fault diagnosis and higher voltage electrical installation testing. A buzzer threshold can also be programmed which will re-familiarise the traditional electrician with ‘belling out’ a test subject. However, the tester will not conduct a 100V insulation resistance test like that of the MFT1730 and MFT1735. This means any insulation resistance testing in special application environments such as telecoms systems or voltage sensitive environments will need further consideration.

In addition to two and three-wire low current (anti-trip)/high current loop testing, the MFT1720 boasts line-to-line testing in order to record line impedance on a three-phase installation. The MFT1720 can also store a ‘Z-ref’ value (Ze measurement), calculating and displaying an R1+R2 reading after conducting a Zs test, although I can only see this feature used as confirmation that the previously recorded R1+R2 continuity value is indeed correct, having energising the circuit for live testing. ‘Z-max’ however, is a handy loop test function to have. Not available on the MFT1710, the ‘Z-max’ loop function records the highest loop impedance value when testing a circuit. I can see this being a great feature to have if you are testing installations whereby you may not be sure where the final point of the circuit may be.

The Megger MFT1720 will automatically test RCDs as well as three-phase and programmable RCDs. Those in the market for a Megger MFT1710 will not be affected by the exclusion of testing three-phase and programmable RCDs due to the environment in which they are installed, although the automatic RCD test can be crucial even for the domestic installer. Anybody needing to test Type B RCDs (DC current/high frequency) will need to consider the MFT1730 or MFT1735.

Other benefits that favour the MFT1720 over the MFT1710 are the inclusion of a phase rotation test, a remote CAT IV test probe (crucial for CAT IV testing), and the ability to conduct a current measurement which is possible with the purchase of a Megger ‘IClamp’.

Is The MFT1720 Right For Me?

The MFT1720 is a great all round multifunction tester that will suit testing domestic, commercial and some industrial electrical installations. Nevertheless, earth resistance testing is not possible, nor is the ability to store and download test results which may cause issues for those undertaking volumes of installation testing. Some DC industrial installations may include Type B RCDs, and as such, even the MFT1720 may not be the correct choice.

For more information about the Megger MFT1700 Series, check out our overview or the chart below. Next up we’ll be focusing on the MFT1730 and MFT1730 Onsite Multifunction Testers.

Megger MFT 1700 Quick Comparison Chart

MFT1710 MFT1720 MFT1730 MFT1730 Onsite MFT1735
200mA Continuity Test
Automatic Start Continuity Test
Insulation Resistance Test 250 & 500V 250, 500 & 1000V 100, 250, 500 & 1000V 100, 250, 500 & 1000V 100, 250, 500 & 1000V
RCD Test
Automatic RCD Test
RCD Ramp Test
Type B RCD Test
2 Wire Anti-trip Loop Test
Z-Ref Loop Feature
Z-Max Loop Feature
2 & 3 Pole Earth Resistance Test
ART Earth Resistance Test Option
Stakeless Earth Resistance Test Option
Earth Spike Kit Included
Download Memory
Software Included
Leakage Current Measurement Option Option Option Option
Rechargeable
Remote Test Probe Included

If you need any further assistance, we are committed to providing impartial help over the phone and you can contact any of our advisors or myself on 01132 48 99 66.