Ongoing mk rcbo faults

[JB1970]

Not sure if anyone has further information on this but I'm getting nowhere with MK tech department.

I did a CU change recently & fully populated it with MK Sentry RCBOs - all tested ok. I've returned a short while later to complete some works & while testing found all 3 of the B6 RCBO's were faulty. Same fault on each, failing the x5 test at 180 degrees. Thought it may be my tester, had a spare with me so fitted that one & it tested ok. Went to order another two from Screwfix & someone has posted a comment about this same fault.

I've e mailed MK tech with the details - no response so I called them a couple of days later. As soon as mentioned the nature of the fault the first person covered the phone mouthpiece waited a few seconds & hung up! Called back & spoke to someone else who said they were aware of it, it was being investigated & an official response would be made within a day or two (this was June 16th). He wouldn't tell me the affected serial numbers (I know some of them) Heard nothing since.

A bit concerned because I've fitted quite a few of these. The serial numbers are on the reverse side so you need to remove the busbar to get them out & check. Bear in mind that they test OK initially & fail at a later date...

 

[davesparks]

Serious question. Why would you not be able to test direct to the terminals of a Memshield 2 RCBO/Pod?

Because the rcbo is made by adding a pod to the mcb, this retains the existing live terminal, but the live sensing coil is in the pod, after the output terminal.
So testing at the terminal screw doesn't include the live sensing element in the test.
The test connection needs to pass through the tunnel in the pod where the circuit conductor normally goes, so either a short piece of cable or a long probe tip such as the one megger ship with their mfts

 

[Midwest]

An update on my experiences. I have two installations where I have used the suspected faulty RCBO's. First one was rather easy; was on an installation where I'd done the dead tests on a radial, and I went back the other day & carried out the live tests. The RCBO failed the x5 @ 180", which appears to be the common fault. Spoke to my wholesaler, who said bring it back and we'll replace it. However, when I did the manger said MK are carrying out exchange on installed products, but eventually they did just swap it for me.

I rang the 'RCBO Exchange' helpline 0800 376 0013 (don't ring technical, they don't have a Scooby Doo), and eventually spoke to someone. The Bobby Moore is, (most stop $hi$ jokes) products not installed can be replaced at point of sale, installed products have to go through MK, I can see some severe arse covering going on here (from my customers point of view!). You fill out the proforma (#8), MK will make contact with you and send you the appropriate replacements to install. Seems they are replacing the batch coded items, even if they tested okay.

I briefly asked about reimbursement for my time, and MK are offering 30 sockets, or something, but I made no comment to that. BE ADVISED, MK asked how I was aware of recall, I stated originally this forum and they were very interested in forum web address. So perhaps any discussion on recompense, should be in the Arms?

 

[Ian Taylor]

Not sure if anyone has further information on this but I'm getting nowhere with MK tech department.

I did a CU change recently & fully populated it with MK Sentry RCBOs - all tested ok. I've returned a short while later to complete some works & while testing found all 3 of the B6 RCBO's were faulty. Same fault on each, failing the x5 test at 180 degrees. Thought it may be my tester, had a spare with me so fitted that one & it tested ok. Went to order another two from Screwfix & someone has posted a comment about this same fault.

I've e mailed MK tech with the details - no response so I called them a couple of days later. As soon as mentioned the nature of the fault the first person covered the phone mouthpiece waited a few seconds & hung up! Called back & spoke to someone else who said they were aware of it, it was being investigated & an official response would be made within a day or two (this was June 16th). He wouldn't tell me the affected serial numbers (I know some of them) Heard nothing since.

A bit concerned because I've fitted quite a few of these. The serial numbers are on the reverse side so you need to remove the busbar to get them out & check. Bear in mind that they test OK initially & fail at a later date...

Just ongoing with a CU replacement. All MK and Sentry RCBOs. After fitting and testing 4 other units all OK and in spec., I fitted a 16 Amp RCBO, it tested OK at 1 and 5 times, but was noisy in operation - not happy. The next circuit was a 10 amp this failed the test at 5 times with a 40.0 msec at 0 degrees reading! This is why I came on to the forum.
Not happy with the quality of MK products and find the screws poor quality as well. Last time I will be fitting this manufacturer.
Ian T

 

[davesparks]

I thought MK had discontinued their CUs?

 

[timhoward]

I thought MK had discontinued their CUs?

Screwfix are certainly currently selling them on-the-ultra-cheap.

 

[westward10]

They are made by CircPro no idea if it has anything to do with MK but probably doesn't make much difference.