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[Case notes: right connections]


In this regular section we look at cases of poor-quality workmanship, mistakes in installation and shoddy practices. John Rothwell from ELECSA provides an insight on what can go wrong – and how best to avoid it


not be removed because of ‘fused’ plastic sealing the cover to the base plate. It was identifi ed that the water heating controller was rated at 5 Amp and that this was switching an immersion heater of rating 3KW at 240V, which equates to approximately 13 Amps. The controller was therefore overloaded to more than 250 per cent of its maximum rated switching current.


The outcome: The service cupboard housing the water heating controller and water heating system, while not suffering extensive fi re damage, was nevertheless covered with a surface coating of fire debris and required new decoration throughout. Other than damage to decoration, there was no other evidence of structural damage. According to the tenant of the property, the fi re offi cer attending the fi re incident said that this could have been life-threatening had the alarm not been raised in a timely manner (the tenants smelt fumes as they were going to bed).


Case 1


The installation: The electrical installation was in an apartment in a residential apartment block that was approximately one year old. There were several apartments in two apartment blocks. Each apartment had the same electrical water heating specifi cation.


About the author


John Rothwell John Rothwell IEngMIET is a senior inspector in ELECSA’s inspections team and has been working in the electrical industry for 42 years.


What went wrong: The inspection was at the request of the tenant after fi re damage had caused irreparable damage to the water heating controller. On inspection of the heat of the fi re and the damage incurred, it was obvious that the fi re had started in the water heating controller. The upper part of the controller had melted and the cover could


60 ECA Today Autumn 2010


What should have been done? The water heater controller was fi tted by an electrical contractor as a result of a service request. The electrical contractor identifi ed a problem with the existing controller and requested a ‘like-for-like’ replacement from a local wholesaler. While the new item fi tted was not identical to that identifi ed as faulty, it was an equivalent controller produced by another manufacturer. The electrical contractor should have verifi ed the loading of the circuit and then selected a controller with switching contacts at least rated for the load current. It is obvious he did not. While it is understood why the contractor decided to fi t a like-for-like replacement, we believe that this would not have stood up to scrutiny in any case brought against him for negligence if the outcome had been different and had involved serious injury or death.


This could have been avoided by: The contractor should have verifi ed the circuit operating parameters (the circuit current rating) by: ■ Reference to the data displayed on the plate of the immersion heater;


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