Experts Clarify RCD Use After Type B Confusion

Coming up on this week's news. Experts  have moved to clarify the use of RCDs   following widespread confusion over type  B MCBs and type B RCDs. An electrician is   fined £4,000 after he named and shamed  his customer on Facebook over an unpaid   bill. And new electrical testing  rules come into force in the UK. Welcome to Electrical News Weekly. 

Whether you're listening in the van,   on site, or down at the wholesale  counter, I'm Joe Robinson, and I've   been through the best of the electrical  industry news to save you the trouble. And if you think you've spotted the two  words I've been challenged to slip into   this week's show, comment with them  below for the chance to win a prize.

Experts from top organisations have moved to  clarify the use of RCDs following confusion in   the trade over type B MCBs and type B RCDs.  BEAMA unveiled the RCD Handbook, which it   produced in association with leading brands  including ABB, Schneider, Hager, and Legrand. Meanwhile, the Heat Pump  Association launched its guide,   developed with NAPIT and the NICEIC. The heat  pump guide says using the wrong RCD can lead   to tripping or a failure to operate. 

It follows an eFIXX survey last year,   where we found that many installations shared  on a popular Facebook group used type A RCDs. The Heat Pump Association says type A devices can  cause problems. Powering up and down the inverter   can exceed the transient switch-on limit for  type A RCDs, resulting in nuisance tripping. There’s another issue. Heat pumps use  inverter-driven motors to regulate output.  

The power electronics that control motor speed  can produce significant DC leakage current,   which may impair the electronic circuitry inside  the RCD. This is known as the blinding effect,   and it can result in the RCD  failing to trip during a fault. Additionally, many heat pumps include water  circulation pumps that contribute further DC   leakage current. Some installers believe that  type A RCBOs, which combine RCD and MCB functions,  

offer sufficient protection. And while RCBOs are  a popular option for residential installations,   there is no such thing as a single-module  RCBO with type B earth leakage protection. This presents a challenge for installers trying  to integrate heat pumps into existing systems.   Type B devices are much more expensive than  type A, but the Heat Pump Association says   that if there’s no clear manufacturer guidance  or uncertainty about circuit characteristics,  

a type B RCD should be used. That’s because  it offers the widest range of protection. The BEAMA booklet also warns not to confuse a  type B RCD, which trips on earth leakage, with   a type B MCB, which trips on overcurrent. This  is especially important when specifying RCBOs. It also advises that when using  more than one RCD in the same   circuit, the upstream RCD should be time-delayed  to prevent nuisance tripping and ensure the device  

closest to the fault trips first. And the upstream  device must be compatible with the downstream one.   For example, you should not fit a type A upstream  of an F or B. An F must not go upstream of a B. Links to both guides are in the show notes. If all this RCD chat has left you scratching  your head like a chimpanzee with nits,   don’t worry. We’ve made an explainer video  that clears up the confusion between type   B RCDs and MCBs. The link to  that is in the show notes too.

In other news, a Jersey-based electrician has  been fined £4,000 after he named and shamed   his customer on Facebook. John Peacock,  trading as Star Delta Electrical Services,   posted the names and photos of  his client and their partner,   accusing them of not paying a bill  for electrical work on their home. The post was shared more than 800  times and received over 200 comments,   resulting in the couple receiving abuse. 

They were called “scum” and “rats”,   and their employer and home address were exposed. Even after being notified that the Jersey  Data Protection Authority was investigating,   Peacock continued to post. This  included superimposing his client’s   head onto the bodies of rats and animated memes. The authority said it was a targeted and  deliberate attack and that there was no   lawful basis for sharing the information. 

The investigation also revealed that Star   Delta was not registered with the authority  and had not paid its data registration fee. As a result, the authority issued a  formal reprimand and fined Star Delta   £4,000. It stated that Peacock should have pursued  the debt through the petty debts court instead.

New testing rules have come into force  in Northern Ireland. Private landlords   must now have electrical safety checks carried  out by a qualified person every five years.   These checks must include socket outlets,  consumer units, and circuits. After   the inspection, the landlord receives a  report, and if remedial work is required,   it must be completed within 28 days. This brings  Northern Ireland in line with the rest of the UK.

Still on safety, and in news scarier than a  hammerhead shark in open water, experts have  

warned that some solar panel installations may  be vulnerable to remote cyberattacks. Tech firm   Forescout says PV systems from brands like Sunrow,  Growatt, and SMA have critical security flaws. The most affected components are solar  monitors that let users track performance   in real time. Other issues were found  in cloud backends and sometimes the   inverters themselves. Even if attackers  controlled just two percent of inverters,   they could potentially trigger blackouts, 

according to Forescout. They say inverters   should be treated as critical infrastructure and  protected with strict cybersecurity protocols.

In product news, a German company has developed a  special kit that lets homeowners power their homes   with an electric vehicle—as long as they also have  solar panels. The kit uses the PV grid inverter   to feed power from the vehicle back into the  home. The power unit rectifies and converts the   vehicle’s current to mimic a PV array and feeds it  into the grid as either single- or three-phase AC. If the inverter has emergency power capability, 

it can bridge long outages. If the inverter has   a spare DC input, the unit just plugs in. If all  DC inputs are taken, a connect unit is added to   link the solar string and power unit together.  It uses MC4 connectors and can deliver up to   3,000 watts of power. The controller can be  programmed so that when the EV battery drops   below a set level, it continues powering  the house until storage is replenished.

RF Solutions has launched a simple kit  for remote control of garage doors and   electric gates. The Hornet  Pro includes a key fob and   relay receiver. It runs on 868 MHz FM  with a 150-metre line-of-sight range.