Technical Publications

In-depth technical papers on residual current protection, device selection and modern applications.

Electric Vehicle Charging and the Role of Residual Current Devices (RCDs)

The rapid adoption of electric vehicles (EVs) has driven significant changes in electrical installation design, particularly in relation to safety and protection. Unlike traditional loads, EV charging introduces power el

Applications & Products

Do MCBs Exist?

If you’re new to the electrical industry, understanding MCBs is an essential starting point. An MCB, or miniature circuit breaker, is an automatically operated electromechanical device designed to protect a circuit from

RCD Types & Selection

Does an RCCB Type B trip on DC?

We have witnessed an increase in reports from several well-informed installers relating to Type B devices that do not function correctly in the presence of DC components. For example, one design was marked as bidirection

Applications & Products

Distribution Switchgear

Distribution switchgear to BS EN 60947-3 defines the requirements for low-voltage switchgear and control gear, specifically switches, disconnectors, switch-disconnectors and switch-fuse disconnectors. This applies to equ

RCD Types & Selection

Understanding Type F RCCBs

As electrical installations evolve, particularly with the rise of variable-speed drives, inverter-based appliances, and complex electronic loads, the traditional Type AC and Type A RCCBs are no longer sufficient in all s

VSD, Pumps & Machines

RCD Protection and Selection for VSD / VFD / Inverters

Update your Safety Policy / Site Specification to comply with essential safety requirements for machines containing Variable Speed Drives 2013! Electrical engineering staff and contractors in the UK may not be aware of t

Applications & Products

RCD Protection and Selection for HVAC / Heating & Ventilation

Does your HVAC installation comply with Electricity at Work Regulations? HVAC Equipment containing 3 phase frequency inverters (VSD) for fan speed control can affect the operation of RCDs installed in other parts of the

VSD, Pumps & Machines

RCD Protection and Selection for Packaging Machines

Do Users comply with essential safety requirements when they install and use packaging machines containing VSD associated with RCCBs! Packaging machines containing frequency inverters for speed control connected via cabl

Solar & PV

RCD Protection and Selection for Solar PV Installations

Solar Power Installations – Do you know what type of RCCB to use and why? Do I need an “A” or “B” Type RCCB for my PV System? Assuming an RCCB is required for automatic disconnection - no other design option is available

BS7671 & Standards

18th Edition BS7671 Consumer units and Types of RCDs

18th Edition BS7671: Consumer Units and RCDs Type AC residual current protection has been applied in UK domestic premises, with little consideration for the nature of appliances and loads connected downstream of the RCD.

EV Charging

Electric Vehicle Charging Points - RCD Requirements

EV Charging RCD Selection – Revised Safety Requirements 18 th Edition The 18 th Edition Regulations for EV installations Section 722, includes several changes to improve design safety and performance. One of these change

Applications & Products

RCDs for Harsh Environments

IEE Wiring Regulations - For premises / special locations with harsh environments see Part 7: 702 – Swimming pools 703 – Saunas 704 – Construction / Demolition 705 – Agriculture/ Horticultural 709 – Marinas Process sites

RCD Types & Selection

Selecting the right type of RCD

Selecting the correct Type of RCD – 18th Edition BS7671 In the UK, residual current protection has been installed with little consideration for the nature of appliances and loads connected downstream of the RCD, this can

Applications & Products

Fire Protection and RCDs

Fire Protection – Have you specified the right type of RCD? Government statistics indicate that changes to Fire Safety Regulations and associated regulations e. g. IEE Regs Ch. 42, have resulted in a reduction in the num

Solar & PV

Solar Invertor RCMU and RCD Protection

Solar Inverters incorporating RCM units - Why do you need an RCD as well? CHAZ ANDREWS OF DOEPKE EXPLAINS THE FUNCTION OF THE SOLAR INVERTER RCM UNIT AND SEPARATE RCD PROTECTION REQUIRED UNDER THE WIRING REGULATIONS Some

Testing & Monitoring

Earth Leakage and Residual Current Analysis

Residual current analysis system - DRCA 1 Measurement of leakage and residual currents Current and frequency analysis Long-term measurement Analysis Guidelines for the selection of AC-DC sensitive RCDs Sporadic tripping

Applications & Products

How to specify RCD Protection for Industrial Sites

Specifying residual current protection for the safety of people, plant, premises and continuity of supply. The complex loads associated with today’s commercial and industrial sites require careful consideration to achiev

VSD, Pumps & Machines

RCD Protection and Selection for VSD / VFD / Inverter controlled Pumps

Pumping/VSD Installations – What do you do about RCCB Protection? To safely install pumping equipment containing VSDs and EMC filters connected to a circuit covered by the Wiring Regs (BS7671) requires a detailed underst

Applications & Products

RCD Protection and Selection for Energy Saving Equipment

Energy Saving Installations - RCD Safety The complexity of present-day electrical installations found in many domestic, commercial and public buildings and the existing safety regulations, place a greater demand on the S

Applications & Products

RCD Protection and Selection for Green Buildings

Green Technology - RCD Specification Domestic, commercial and public buildings designed to meet the latest energy standards can contain a range of energy saving devices and technology from simple LED lighting, appliances

EV Charging

18th Edition - RCDs Mode 3 EV Charging

Mode 3 Charging: RCDs – Considerations for Installation Approval Mode 1 and 2 charging were never intended to provide permanent solutions for charging Electric Vehicles. The in-cable control box (ICCB) built into a mode

Testing & Monitoring

RCD Testing 18th Edition Basics

RCD Testing 18 th Edition Basics Understanding the basics, helps us make reasoned decisions. In practical situations and under time constraints, it is easy to lose sight of why we carry out specific tests on RCDs and und

RCD Types & Selection

18th Edition - Type F RCD, Deep Dive

18th Edition – Type F RCD, Deep Dive A recent discussion with a customer, highlighted that apart from the basic characteristics, when you look on the WEB information on Type F RCDs is quite limited. This article attempts

BS7671 & Standards

18th Edition 722 Amendment 1: RCDs & RDC-DDs Requirements

18th Edition 722 Amendment 1: RCDs & RDC-DDs Requirements Effective RCD protection for an EV sockets relies on the correct specification of the associated EV charging equipment and the RCD. Don’t leave it until the insta

VSD, Pumps & Machines

Pumps, Water and RCDs?

Applications for inverter speed controlled water pumps associated with RCD protection, can be challenging even for Companies and Staff, with specialist design experience and knowledge. General purpose inverters used for

Heat Pumps

Heat Pumps – Type F or Type B RCDs?

BS7671:2018 Amd 2 Heat Pumps – Type F or Type B RCDs? Inverter speed controlled pumps and compressors circuits require specific Types of RCD. Refer to BS7671 Amd. 2 for the basic requirements, relating to the use of RCDs

EV Charging

EV Charging – Is it an RDC or RCD?

The similarity between different residual current Protection devices, the different Types, and devices that do not offer protection but detect residual currents, can trip up even some experienced contractors and installe

EV Charging

EV Charging – Selectivity between RCDs

Chaz Andrews Doepke Technical Manager – Outlines key points and selection possibilities when connecting RCDs in series for EV installations. 722 Amendment 2 – Design Rules The IET Code of Practice (CoP) for EV Charging E

Testing & Monitoring

Residual current protection or residual current monitoring?

Chaz Andrews Doepke Technical Manager – Outlines key differences between RCMs and RCDs. This article is aimed at Staff on commercial and industrial sites who have a limited knowledge of BS7671 requirements. RCDs (RCCB, R

Testing & Monitoring

RCDs Which tests do I need to complete?

This article covers a number of recent discussion topics with customers, relating to testing different Types of RCD. Our original article dated October 2019 goes into more detail on background subjects. RCD Testing 18th

Applications & Products

Contactors & Safety - Understanding the Standards

Chaz Andrews Doepke Technical Manager – Outlines key points related to equipment designs that utilize contactors in functional safety applications. The concept of domestic smart load management will become standard pract

BS7671 & Standards

BS7671 Amendment 2: - Emergency Stop or Off for EV installations?

BS7671 Amendment 2: – Emergency Stop or Switching Off for EV installations? Chaz Andrews technical manager at Doepke – discusses the crucial difference between Emergency Stop, Emergency Switching Off and BS7671 product p

BS7671 & Standards

BS7671 Amendment 2: - 704 Construction & Demolition Site RCDs

BS7671 Amendment 2-704 RCD Protection: Construction and demolition site distribution boards – hidden danger UK construction – It’s a tough life Using poorly maintained or out of date electrical equipment in dangerous env

EV Charging

BS7671 Amendment 2 - 722 Mode 3 chargepoint standards?

BS7671 Amendment 2 - 722 Mode 3 chargepoint standards? EV Installers are responsible for checking that equipment and products they install in the UK, meet the appropriate product standards and the requirements of BS7671,

Heat Pumps

BS7671 Amendment 2 Heat Pump RCDs v2 March 2024

BS7671 Amendment 2 - Heat Pump Installations: Regulation 531.3.3 Are you involved directly with Heat Pump (HP) installations or expecting to deal with an existing installation? Having a better understanding of RCD requir

EV Charging

Mode 4 EV (DC) charging: AC side RCD selection

If you are involved in the regular installation of DC fast chargers (Mode 4), you will already be familiar with the significant differences between individual manufacturers’ performance characteristics and the impact on

Heat Pumps

BS7671 Amendment 2 - Heat Pump Installations – Type B RCDs

RCCB suitable for HP application. Marking the RCCB with HP symbol aids identification on site. Heat Pumps (HP) producing leakage currents above 1kHz, will not be compatible with Type B RCDs that are only manufactured to