RCBOs replacing MCBs

[Joeski1953]

Newbie here, joe just joined thanks in advance.
Cutting a long story short, My brother has a property he's renting out, current certification advised plastic consumer unit needed changing, changed to metal with RCBOs and anti-surge. It will need a retest obviously, has anybody ever come cross led (internal controls and drivers) tripping the RCBO? All other fittings (with no internal controls) work, There is upstairs and downstairs and sockets all on separate RCBOs, I know I've heard about spiked inrushes etc, but what's the remedy? The fitting is very extravagant with bars that light up ( leds 4 long shaped bars) When this gets disconnected nothing trips. If that goes back up all lights upstairs will work, but when we switch this one on it trips? Has anybody come across this before, i will post a picture of fitting and control ballast if it helps, he wants it (being very expensive) back up.
Obviously we will need a retest but we cant do this until we have something on the landing. Previously the unit was plastic with mcbs, nothing ever tripped, it was certificated as he let it previously. He is acting on the advisory.
I'm just wondering if I'm, wrong with my speculation, and what to do next.
Thanks to all in advance, (go easy I'm new)

 

[Andy™]

may need a type C instead of B, or possible a 10a instead of 6a

and why does it 'obviously need a retest'? existing EICR (even if unsatisfactory) is still valid, your EIC/MWC for remedials will cover the unsatisfactory on the EICR

 

[Joeski1953]

may need a type C instead of B, or possible a 10a instead of 6a

and why does it 'obviously need a retest'? existing EICR (even if unsatisfactory) is still valid, your EIC/MWC for remedials will cover the unsatisfactory on the EICR

Thanks for that, firstly I'm not sure of type that was supplied with the unit, will check when I go back tomorrow, secondly I'm not sure of landlords rules and regs ( But will find out) coupled to that my brothers going off what the letting agents told him? If your right then i,ll pass all that on, I,ll certainly look into it.

 

[Murdoch]

Did the old board have RCD’s?

Who is issuing the EIC and Part P?

 

[kerching]

If the existing board has RCBOs AND is not showing signs of thermal damage why does it need changing?
A) IGNORE EVERYTHING a letting agent tells you
B) See A)

 

[SPECIAL LOCATION]

Have you tested the fitting to try and establish if it is the MCB element or RCD element of the RCBO that is causing the power disconnection?

Have you double checked the all to common issue with lighting circuits of someone connecting neutral to a different circuit?

 

[binky]

Whoever fitted the new board should be sorting this out....

Ok fairly simple test with a pair of voltage probes, disconnect neutrals at the board for both lighting circuits and test to see if there's continuity between them. Knock off both circuits first of course.

 

[kerching]

Just re read Op.....so the board HAS already been changed for RCBOs and SP?

 

[Murdoch]

Just re read Op.....so the board HAS already been changed for RCBOs and SP?

That’s how I read it

 

[Joeski1953]

That’s how I read it

Yes mate, was mcbs, now RCBOs every circuit with additional surge protection device.

 

[Joeski1953]

Did the old board have RCD’s?

Who is issuing the EIC and Part P?

Did the old board have RCD’s?

Who is issuing the EIC and Part P?

No mate, the old board had MCBS, but was plastic, doesn't meet letting standards, changed to 8 way RCBO and SPD. All circuits work its the landing light that trips the RCBO, its a large led type with long leds (4 of them) Im hearing borrowed neutrals but why? they are 2 separate circuits one up one down.

 

[Murdoch]

Yes mate, was mcbs, now RCBOs every circuit with additional surge protection device.

So you made the changes ...........

No testing either

 

[kerching]

Were the previous MCBs he same 'type' as the RCBOs i.e. Types B or C? Just trying to eliminate the 'surge' option


Disconnect LED fitting, fit a standard lampholder and lamp, retry
If it trips it's a borrowed neutral ( highly likely ) landing light feed from ground floor and neutral from upstairs
If it doesn't then it's a Moody fitting or surge

 

[Fleeting]

Connect both lighting circuits into one rcbo and see what happens.

 

[binky]

Im hearing borrowed neutrals but why? they are 2 separate circuits one up one down.

The hallway often has both circuits present, and older installations don't always have proper two way switching, so a neutral gets taken from the other circuit to convert to proper two way switching. It's a common fault that won't upset MCBs, but will trip RCBOs every time.

 

[Joeski1953]

Were the previous MCBs he same 'type' as the RCBOs i.e. Types B or C? Just trying to eliminate the 'surge' option


Disconnect LED fitting, fit a standard lampholder and lamp, retry
If it trips it's a borrowed neutral ( highly likely ) landing light feed from ground floor and neutral from upstairs
If it doesn't then it's a Moody fitting or surge

Thats next check, I,ll let you know later, Most are saying that, do you know best way round it, (EASIEST) Sep feed to downstairs switch landing side?

 

[binky]

Thats next check, I,ll let you know later, Most are saying that, do you know best way round it, (EASIEST) Sep feed to downstairs switch landing side?

really hard to say without seeing the job. Easy answer is put both lighting ccts in one RCBO.

 

[poni]

(EASIEST)

take the light down and fit a lead and plug top and plug it into a socket and see if that circuit trips

 

[Joeski1953]

Connect both lighting circuits into one rcbo and see what happens.

really hard to say without seeing the job. Easy answer is put both lighting ccts in one RCBO.

Yes, doubling up clears problem.

 

[Joeski1953]

really hard to say without seeing the job. Easy answer is put both lighting ccts in one RCBO.

Done that but its not what we had previous, Id like to keep as was.