Replace rcd?

Is it required? - No.
Others may offer different opinions and say with the introduction of modern appliances a change to Type A RCDs could be considered.

 

I would say yes it's the right thing to do.

 

I would say it depends on the type of equipment you use in the house. If you have a lot of computers or inverter driven motors etc that can put out DC on the mains then yes, if like me you're an old tight git that sticks in the past then not so important.

 

Going by the book, I suppose it is. In general, all RCDs should be Type A, unless supplying fixed equipment that doesn't have DC components. In the latter case, a TYPE AC can be used.

Tomorrow, I'm fitting a socket for access equipment and intend to use the existing Type AC. On the minor works certificate I'm putting it down as a departure.

 

@Simonson82 - Here is the advice from the IET when designing new circuits.

What are the changes to the requirements for selection of RCD Types?
Before we look at testing RCDs, it is worth pointing out that the requirements for selection and erection of RCDs have been amended. Regulation 531.3.3 of BS 7671:2018+A2:2022 states that the appropriate RCD shall be selected according to the presence of DC components and AC frequencies. Further, Type AC RCDs shall only be used to serve fixed equipment, where it is known that the load current contains no DC components.

Type AC RCDs are affected by residual DC components and can become desensitized or ‘blinded’ and may not operate within the required time or, in some instances, may not operate at all. Table 1 summarizes the various types of RCD referred in BS 7671:2018+A2:2022 and their resilience to DC components.

Given the prevalence of electronic equipment in most installations, it is difficult to see how the electrical designer will be able to justify the use of Type AC RCDs. Many manufacturers have discontinued Type AC RCDs, preferring to supply type A as a minimum. Therefore, in future it is possible that Type AC RCDs will become obsolete due to lack of demand and Type A RCDs will become the common choice for most new installations, so it is important to understand the changes to the requirements for RCD testing.

Extract from - Changes to RCD testing in BS 7671:2018+A2:2022 (theiet.org)

 

I would be a little concerned that with a 100mA RCD on the incomer and no RCD on the sockets it isn't dead straight forward really.

 

But it is not a departure as it is permitted. Maybe worth a note on the MWC though.

Departures are deliberate decisions not to fully comply with the requirements of the Wiring Regulations. You are complying!

 

Was this intended for another thread, maybe?

 

I would be slightly more than concerned. That would mean no additional RCD protection at all.

 

I think so, hes lost his marbles lol

 

Oops!

Mars bar to the man who spotted todays idiot post

Confused by 2 about RCD's together lol. Old age don't come alone.

 

Shuttup Tubby

 

I'm off to bed, the nurse is waiting.

 

No I'm not! Regulation (boring..) 531.3.3. The word 'shall' rears its ugly head again. Can't use Type AC unless it's for fixed equipment without DC components

 

Nothing to do with modern appliances. Back in the 1930s radios typically used half wave rectification which put huge DC components on the supply. This practice continued for over 50 years by which time large power colour TVs did the same thing.

 

https://electrical.theiet.org/wirin...g an AC Type RCD,fault current on the circuit.

 

And you could plug your iron into a convenient lighting pendant.
But I should have taken account that the OP might still have a 40 year old TV.

At least we can agree on the price of fish

 

It would be potentially dangerous so it would be a C2 in my opinion.