Metrel MFT mi-3152 RCD test

[John-]

Hi
Recently invested in one of these. Impressed! Until...

i came to test my 100mA type A RCD. Long story short, it would not test correctly until
I set it to Type AC, rather than A. My Mega MFT worked fine, only as it is so old it has no options for S type. I did try all the settings in the individual and sequntial test mode.

Anyone else have this with their Metrel 3152?

i will call Metrel on Monday to confirm.

cheers

john

 

[John-]

So i called Metrel. I updated my firmware. Still getting the same issue. The RCD goes beyond 500ms and does not trip when set to Type A. It is a type S, with a fixed delay of between 200 - 300ms, accordimg to the data sheet. Yes i am also setting to type S.

100A 4 Pole 100mA Type A Time Delay RCD

Insulated DIN rail clips

www.cef.co.uk

Looks to me like the Metrel tester has an issue with S type on type A (pulsed DC) as it trips at around 340ms when the tester is set to type AC. I even bought and installed the same RCD to check that it was not the RCD at fault - i get the same issue.

i have filmed it and will send to both MCG and Metrel over the weekend. Will update thread as and when.

it also seems to
Me that the tester does not go up to 1 second, max aloud for TT distribution circuits. Raised this but not heard back.


Cheers

john

ps i am disappointed with battery life. The tester will not last a full day without further recharge or another set of batteries...

 

[John-]

Update...

MCG (CEF) really lightning fast about pulling one for factory, checking it, asking about batch codes etc and confirming they see no issues at the factory end.

Metrel however... The tech support guy i spoke to was very helpful, it has been logged in Jira system but... I have had no update on progress... Twice asked and twice the same response, it has been escalated to technical.

Update again soon, but looks to me like a bug or two in the tester, one of which is it only going up to 500ms...

 

[John-]

Ok. Final update.

in summary it was the RCD! Or I should say both MCG S Type RCDs that i tried.

Metrel carried out a test and filmed it. For them the Type A test worked, it passed. However, only just! The test will allow up to 500ms for a pass in accordance with the manufacturing standards. The test came out at 470ms…

it should be around 230ms, according to MCG blurb.

Any way. I installed a more expensive Hager S type 100ma A tyoe RCD and this tested out perfectly.

Moral for me, avoid MCG S type RCDs. I use their A type 30mA RCBOs, and do not have the same issue.

MCG have not resonded further. I am still waiting for an update from Metrel on other issues i have…
Cheers
John