NAPIT Codebreakers #11

NAPIT Codebreakers #11

Need help with cracking those EICR codes?

The technical team at NAPIT, with the help of the 18th Edition Codebreakers publication, answer your latest coding queries.

ALL CITY SPARKS: A client moved into a new house and asked me to make a quick visual inspection of the property to check that there was nothing immediately dangerous. Found this contactor for an underfloor heating circuit – incorrectly wired and dangerous. However, all connections appear to be safely housed and isolated in this plastic tub!

Codebreakers: At first glance, I’m sure that some clients would see this as serving a purpose, not very pretty, but equally not as expensive as the actual enclosure would be. Unfortunately, though, this is the thought process and lack of understanding we face almost daily. In this case let’s break down the individual parts and take them on their merits, or lack thereof.

  1. The plastic box, which is obviously a low-cost storage box, can be found at most DIY or low-cost shops. These are designed to take a storage load and not be bolted to a wall. Many are generally susceptible to the environment and some will become brittle over time, while others are brittle by design, due to their economical manufacture. Given its potential for structural demise and lack of design for this type of use, it shouldn’t be used for this purpose; all electrical enclosures must meet a specific British Standard. As we don’t expect to find voltage inside storage boxes, it’s a requirement for labelling with the voltage present, although this pales into insignificance with the rest of the install.
  2. Contactors and similar switch gear are designed to be mounted on a rail – in this case a DIN rail is required. This mounting allows for safe mounting without damaging the equipment and allows adequate cooling during use. Bolting the contactor directly to a piece of wood could leave the device damaged through stresses it wasn’t designed for, and any cooling requirements have been compromised by what is obviously not a fire-resisting backing board.
  3. Cable management and containment is not acceptable, the earthing terminal is neither adequately mounted and supported, or correctly terminated. The cables making up the connections are poorly terminated and not identified in any way. The Neutral cable entering the top of the device seems to show signs of overheating and has discoloured the backing board, a clear indicator of thermal damage.
  4. Access for maintenance and ongoing inspections is also an issue here, as the storage box is permanently fitted.

There may also be isolation and protection issues, but without further knowledge of the installation and the proximity of other equipment, I’ll leave that out of the observations.

RAMON JIMENEZ: I found this nice, low-profile cable joint on a ring circuit feeding a socket. The wires were just twisted together!

Codebreakers: This kind of alteration to an existing circuit is so dangerous. If the lid to the mini-trunking is knocked off or pulled off by a curious child, there is little or nothing preventing contact with live parts. In most cases the insulating tape peels off or becomes brittle and breaks away.

More of a concern is that the joints are not made with any kind of mechanical crimp or solder connection. Where any kind of maintenance-free (MF) terminal devices are used, these should be taken inside an enclosure designed or declared fit for that purpose by the manufacturer.

At the very least the joints should be crimped and encased in heat-shrink (possibly multiple layers to give added strength and protection). It isn’t best practice to put joints in containment such as this, however I do realise that in some cases the requirements are such that there may be no other workable solutions.

Where terminations are not MF, i.e., screw terminations, they must be taken into an adequate enclosure, as mini-trunking doesn’t fulfil this requirement. There will be increased strain on the terminations, from this installation method, which will also need to be coded.

RICHARD WILLIAMSON: Found this after a call out recently.Β The fuse in the owner’s lights kept blowing, so after replacing the wire four times he called us! Line to neutral fault. There is no CPC in the cable which had been left hanging outside live for more than 18 months. It certainly adds new meaning to the expression β€˜croaked it’!

Codebreakers: We often see cases where wildlife has come to an unfortunate end from contact with electricity. In most cases the said wildlife has found a way into an enclosure and succumbed to the effects of electrocution.

The most frightening thing here is that this could very easily have been a person, as the live parts were not in an enclosure, but hanging freely to contact whoever or whatever came along.

Regardless of the containment issue of the cable, it was not adequately terminated and taken into an enclosure, which is a requirement of BS 7671

This shows how important it is to make safe, isolate or remove unwanted circuits, to ensure no one is injured, after we have no further use for a particular part of an installation. At the very least, if complete isolation and removal can’t be carried out, the dis-used part of a circuit must be terminated appropriately and safely.

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