Ring Final Circuit
Design & Installation Featured Technology
What are the different types of circuit?
The key thing to remember when selecting the type of circuit for an electrical installation is the requirements stated in the IET Wiring Regulations. These are that: The number and type of circuits required for lighting, heating, power, control, signalling, communication and information technology, etc, shall be determined from knowledge of: Location of points of power demand. Loads to be expected on the various circuits. Daily and yearly variations in…
Design & Installation Technology
Taking the feed (supply) to a switch
In this video, Gary Hayers form Tresham College  looks at the practice of taking a supply to a switch. This follows another tutorial where Gary explains 3-plate loop-in method.   Student training aid for the connections required when the feed is taken directly to the switch. Also, how to wire two way and two way and intermediate switching. Video explains the connection required within switches. The circuit is wired in…
IP4X Fitting
Design & Installation Technology
Trunking and IP Ratings
NAPIT’s Bill Allan discusses the application of the IP Code to cable trunking. In this article, we will discuss the application of the IP Code to cable trunking. Regulation 521.10.1 Regulation 521.10.1 of BS 7671 requires that non-sheathed cables (ie. ‘singles’) for fixed wiring can only be installed in cable trunking if the trunking provides at least the degree of protection IPXXD or IP4X and if the cover can only…
Safe Isolation
Design & Installation Technology
Introduction to isolation and switching
This article from ELECSA provides a brief overview of isolation and switching how the terms are used in BS 7671. The term ‘isolation and switching’, as used in BS 7671, embraces four distinct concepts, each with its own particular requirements for safety. The four concepts are: isolation, switching off for mechanical maintenance, emergency switching, and functional switching. This article will only consider isolation. Summary of the four safety concepts Switching off…
Identifying electrical accessories
In this video, GSH Electrical and  Tresham College introduce basic electrical accessories. This video has been made as a student aid for identifying basic electrical accessories. We look at 1-way, 2-way and intermediate switches, lighting points and socket outlets. It’s important in the early stages of training to be able to recognise and name these items.   All products are donated by Scolmore
extraneous conductive parts
Design & Installation Technology
How do I determine an extraneous conductive part?
This article provides some simple guidance on how to identify extraneous conductive parts to help you avoid the unnecessary installation of protective bonding conductors. It should be appreciated that exposed metallic parts not forming part of the electrical installation are not always extraneous conductive parts as defined in Part 2 of BS 7671. Therefore, as explained in this article, to avoid the unnecessary installation of protective bonding conductors, it is important…