Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
Identification help: Is this RCBO Type A or Type AC?
I've formally started my journey into learning more about domestic electrics and I'm currently looking at our consumer unit and garage DB to see if our existing protection is Type A or Type AC. I know Type A is the modern standard for anything with electronics/inverters, but I’m struggling to be 100% sure based on the markings.
Looking at the RCBO in the image below labelled "Socket", can anyone confirm from the markings on this MCG RCBO if it is a Type A?
🔥 Britain’s Heat Pump Shitshow
How Installing a Heating System Became a National Nervous Breakdown
Free UK shipping.
Rewritten and updated for 2027
📘 From Zero to Heat Pump Hero
🛠️ Bodge Buster
New to heat pumps?
Take the Heat Pump Fundamentals course and use INTRO50 at checkout for 50% off.
Posted by: @editorI've formally started my journey into learning more about domestic electrics and I'm currently looking at our consumer unit and garage DB to see if our existing protection is Type A or Type AC. I know Type A is the modern standard for anything with electronics/inverters, but I’m struggling to be 100% sure based on the markings.
Have you decided to become a heat pump installer? There appears to be a market!
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
Could perhaps the following pictures be of any use to you?
One is in english but blurry, the other is in greek but clearer (so that you can more easily discern the markings per type).
I was not able to see any of these markings in your photo, may be if you pull the switch down there are markings behind the lever….
Posted by: @editorLooking at the RCBO in the image below labelled "Socket", can anyone confirm from the markings on this MCG RCBO if it is a Type A?
Apologies for arriving here late!
From what we can see of that RCBO, there is no indication of its Type.
The 'B' in 'B16' refers to the curve which defines how fast it responds to over-current faults.
Beware of Screwfix who often describe trips incorrectly!
It's possible that there is writing we can't see hidden behind the toggle lever, beneath the words "Test Monthly".
One of my gripes is that simply isn't sufficient room on the 18x47mm visible part of a single-module-wide trip to tell us all we need to know.
Even if it were labelled with the relevant symbol for its Type, we'd still need to remove the front cover to see if it's uni- or bi-directional.
Could you take off the CU cover and post another photo here please?
Save energy... recycle electrons!
- 27 Forums
- 2,758 Topics
- 64.9 K Posts
- 1,790 Online
- 7,162 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
RE: Where heat loss surveys seem to go against practical reality
@cathoderay I started to record oil usage per month on ...
By ian33a , 1 hour ago
-
RE: Next steps on my ASHP journey: Radiators and Pipework
@bobflux The hydraulic simulator is very interesting...
By Rob of York , 5 hours ago
-
RE: 7kW EV Charger Options Advice
Thanks. Yes, we have patchy 4G. The only option we had ...
By Rusty , 10 hours ago
-
-
RE: Being screwed over by Volkswagen Audi Group
Thanks, @batpred. That integration is the one I have in...
By Majordennisbloodnok , 1 day ago
-
RE: How Accurate Is My DIY Heat Loss Calculation?
@batpred I suspect it will be more this year. I had 9 ...
By AndrewJ , 1 day ago
-
RE: Surface mount or bury primaries for heat pump installation?
@jamespa It's rusting 🙂
By tomasmcguinness , 1 day ago
-
RE: Glass lined Cylinder for private water supply
Thank you, once again, for your replies. Yes...
By ian33a , 1 day ago
-
It’s been out a few days and Amazon has already attache...
By Mars , 1 day ago
-
RE: Missing flow temperature in Heat Geek proposal
Yes, and this is another point I agree. We did find a f...
By Batpred , 1 day ago
-
RE: Problems with sizing a replacement for a Viessmann Vitocal 200-S
A very good point. In effect, the DHW pipework is an em...
By cathodeRay , 2 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@tim441 Here are those same three month periods for 202...
By Toodles , 3 days ago
-
RE: Adding additional Solar Panels to a DC coupled battery system
@transparent thank you for your reply above. As alway...
By Old_Scientist , 4 days ago
-
RE: Adventures in heat loss calculations
@rob-of-york — thanks for posting this, all very useful...
By cathodeRay , 6 days ago








