Stroma Certification Technical Advisor, John Peckham, reviews the Kewtech KT65DL Multifunction Tester.
As a long term user of test equipment, I usually prefer separate meters as I have found that a Multifunction Tester (MFT) does not typically perform consistently on large installations.
To evaluate the Kewtech KT65DL, I have trialled it on a mock-up installation and on a large commercial installation. I also gave it to my City & Guilds 2395 students, who are experienced electricians and already have the City & Guilds 2391 or 2394. I also asked my experienced inspecting engineers to trial it on a large 3 phase installation.
The first thing I noticed was the spacious, nylon transit bag which the KT65DL comes in, which has plenty of space for screwdrivers, testing adaptors and other various pieces of testing tools. I was also overjoyed to see that it came with the Kyoritsu lead set, probes and strong crocodile clips with parallel jaws. I have tried many leads and found the Kyoritsu to be the best. If your meter, of any make, has 4mm sockets, I highly recommend the Kyoritsu leads.
I was disappointed that at least the brown probe supplied was not fused. For peace of mind, I like to put a fuse between a high current bus bar and myself. Both my students and my engineers liked the test probe with the remote test button.
The meter has a user-friendly shape and a very clear display. There is an additional protective cover, with user instructions inside, to protect the controls and screen. However, it was noted that the neck strap needed some padding if you were to work with it for a few hours testing.
The KT65DL is able to fulfil all of your testing requirements, with the addition of an earth resistance testing facility. It can also be used as a Portable Appliance Tester if you purchase an additional adaptor, a useful addition if you carry out occasional Portable Appliance Tests.
Carrying out Continuity Testing and Insulation Testing is straight forward, just like any other meter. There is a very useful red LED to indicate a high voltage when IR Testing, to alert you if your test has charged the installation up to the test voltage going out and when it is safe to disconnect the probes.
RCD testing is fast on the auto test; the instrument can test types AC, A and S type RCDs in the range 10mA to 1A. The auto test 5 results are shown all on the one screen so you don’t have to scroll through to see the highest trip times; this was considered to be a very handy facility by all parties. The meter has an RCD ramp test facility which is very useful for fault finding.
For Loop Testing, the KT65DL will test down to 50V which is very useful for carrying out testing on 110V building site installations. Loop Testing and Prospective Fault Current Testing are separate switch functions on the meter with the loop testing requiring a 3 lead connection if you want a 2-digit or 3-digit resolution for your loop test results. It has a high current loop test facility and a low current test facility for RCD protected circuits. After carrying out multiple tests at both high and low currents on a non-RCD socket with the KT65DL, and also with 3 other loop testers, I found the results to be remarkably consistent.
One of the main tests for any loop tester is on a low impedance high current supply. To get accurate results, you need a high current tester, often costing around £5000. With an ordinary loop tester, the best you can expect is a ‘ball park’ test result. I used the KT65DL to get a Ze test result on a panel board close to a 1 MVA transformer. I carried out a 2 wire high test using the PSC range and a fused probe. The meter returned a result of 0.02Ω, whereas my high current individual loop tester gave a result of 0.03Ω. I calculated the actual Ze and the calculated value was 0.014Ω which was a much better performance than I have experienced with other MFTs. The KT65DL has built in a database of maximum values of Zs for circuit breakers and fuses compliant with BS7671 Amendment 3 that test readings can be compared with automatically.
After researching the retail price of the meter online, I found that it can be purchased for approximately £822 (inc. VAT). I think if any electrician is looking for an MFT the KT65DL would be a sound purchase and I recommend a hands-on evaluation.
If you require further support throughout your electrical work, contact our Assessors on 0845 621 1111 for expert technical advice.