B-Type RCDs

Are installers really fitting B-type RCDs as outlined in the wiring regs for high frequency solar & battery inverters?





I can't fathom any client wanting to pay more for a trip switch than their inverter cost..


Installers wouldn't perchance be fitting Trip Curve B MCB/RCBO devices instead?..:(


Has anyone got a source for inexpensive properly certified jobbers?

Would any users with a since ~2016 PV and or battery install mind awfully posting pics of their solar and or hybrid inverter consumer unit(s) with the circuit breaker text in focus, please?
And state what the inverter make and model is.


I'd like to see what the industry standard is.
Thx.

Dardania

What's the problem here - is it meant to be an RCD (as in earth fault) protection only, rather than over current?

It's a class of RCD (RCCB - Earth Fault) that detects both DC and AC and they're north of €500.
Standard RCDs can fail to operate in fault conditions due to injected DC from the lack of isolation from the battery or PV in a high frequency topography inverter (most are because it's "cheaper").

It's in the building regs that there has to be one and it's in the installer notes for the SEAI grant that there has to be one. I'm wondering are people getting them and are the installers equipped with the facilities to test them.

Dardania

Wow - I never knew about this but it makes sense.

Clicky

Another feather in the cap for low-frequency transformer inverters.

Gumbo

I'll check mine later.
I only have Solar PV-Invertor-Divertor. No battery.

Dardania

Sir Liamalot wrote: »

Clicky

Another feather in the cap for low-frequency transformer inverters.

Thinking a bit further on this - would a capacitor not help a lot here to filter out DC?

Dardania

Dardania wrote: »

Thinking a bit further on this - would a capacitor not help a lot here to filter out DC?

Nope.

Tow

The use of Type B is touched on here, at 26 minutes. AC will be banned.
I don't think he covers PV in the video, but maybe wrong.

https://youtu.be/bLIyTYhWs_0?t=1558

Dardania

Sir Liamalot wrote: »

Nope.

Why?

Dardania

Dardania wrote: »

Why?

Capacitors are DC.
DC is the problem for A, AC and F type RCDs

Dardania

Sir Liamalot wrote: »

Capacitors are DC.
DC is the problem for A, AC and F type RCDs

So, the capacitor ought to filter out the DC...if I remember my electrical engineering correctly?

Capacitors resist changes in voltage. They are DC collectors. The problem with regular A and AC RCDs is their ability to operate within specified parameters with a DC presence on their sense conductors.
If anything they would make it worse/do nothing & reduce power factor.

Capacitors can be used to filter ripple and noise, and smooth a chopped/pulsed or variable voltage.
They do not make installations compliant with ET101.

Whether or not real world results could vary; it would prove extremely difficult to test it's correct operation in normal operating conditions as results would depend massively on what the inverter input is and in the case of battery inverters what the appliance line noise is.

ET101

You could fulfil thuther clause

ET101 wrote:

Where the PV system cannot, by reason of its construction, feed DC currents into the electrical installation (i.e. AC system), a Type B RCD shall not be required, and electrical protection of the AC circuit shall be in accordance with ET101:2008

..with a for example €500 isolation transformer :pac:

Gumbo

Sorry for the long delay but this is what’s fitted in my fuse board from the Solar PV. Mine were fitted around September 2017.

Yurp. That's a non-compliant A type. I'd take that up with your RECI...they owe you a very expensive circuit breaker.

If your inverter is fully isolated from the primary input it is ok, you can ask them this. I'm sure they will know the difference.

Gumbo

Sir Liamalot wrote: »

Yurp. That's a non-compliant A type. I'd take that up with your RECI...they owe you a very expensive circuit breaker.

If your inverter is fully isolated from the primary input it is ok, you can ask them this. I'm sure they will know the difference.

Would be interesting to see if anyone has the Type B switch.
Where in the regs is the requirement?
Is it ET101?

Also, my EV Charger is a type A switch.
According to your link it should be a Type B also.

H.E. Pennypacker

Here's mine - I've no idea what to look for so any info welcome. Inverter is a Trannergy SGN1800TL:

Gumbo

H.E. Pennypacker wrote: »

Here's mine - I've no idea what to look for so any info welcome. Inverter is a Trannergy SGN1800TL:

It says B20 so initial thoughts is that it’s a Type B switch BUT, the logo is the same as mine and when crossed referenced on the Hager site, it’s a Type A, same as mine.

H.E. Pennypacker

H.E. Pennypacker wrote: »

Here's mine - I've no idea what to look for so any info welcome. Inverter is a Trannergy SGN1800TL:

That's not an RCD that's an RCBO (over current trip curve ...also non-compliant.

It's in the regs ET101:2008
Subsection: 712.411.3.02

Yes EV chargers are required to have B type RCD fitted too.
EV charging specific RCDs are available for this.

Gumbo

Sir Liamalot wrote: »

That's not an RCD that's an RCBO (over current trip curve ...also non-compliant.

It's in the regs ET101:2008
Subsection: 712.411.3.02

Yes EV chargers are required to have B type RCD fitted too.
EV charging specific RCDs are available for this.

Thanks. I’ll check those regs during the week.
2019 version due for release in a few months also.

0lddog

Im wondering what the Regs in countries that offer a FIT that encourages domestic microgeneration require.

Anyone familiar with, say, UK / German Regs ?

18th Edition Uk to include installation and testing of B-Type RCDs for EVs and non-isolated PV inverters. Spurring a revision and up-spec of multi-function tester requirements for installation testing.

German company SMA has had the requirement of a B-Type RCD for their Sunny Island Range since I expect, the product release.