13 October 2013

The Consumer Unit – the heart of the home

Dual split-loaded CU with Surge Protection Device

BACK IN the day it was called a fusebox. With the introduction of circuit breakers replacing fuses it became known as a consumer unit or CU. The term consumer unit principally applies to domestic premises, and throughout the Costa Blanca dwellings normally have a 230 volt single-phase power supply to theirs.

The consumer unit distributes electricity to appliances and safeguards the system to help prevent electrocution and fire. With the limited power supplies that are available, it is essential that the consumer unit is adequately equipped to deal with overloading and leaking electricity. The consumer unit is the heart of the home, and should be treated as such.

It is usually located near the front door and should consist of two compartments. One compartment is solely for a power control switch (ICP) which is fitted under an authorised seal by Iberdrola. The other larger compartment is for the consumer, and houses the safety devices for subsidiary circuits.

Since 2002 following publication of the latest Spanish electrical regulations, the basic installation for a dwelling requires a consumer unit to have five sub-circuits. Properties built prior to 2002, can have four sub-circuits, or even only two. Very old properties can be found fitted with only a Mains Isolator and a Residual Current Device (RCD) without any sub-circuits.

The basic installation is protected by a single RCD. This can cause secondary safety problems with loss of lighting and defrosting of food if a trip occurs.

Large properties with higher electrical consumption should have consumer units fitted with additional safety devices. Extra protection is needed for a Jacuzzi, swimming pool, tumble dryer, air conditioning and heating systems.

For external electrical fixtures and fittings it is preferable to have them independently controlled in the consumer unit, enabling the sub-circuits to be easily isolated in the event of a fault. This prevents major disruption to the electricity supply inside the property, which can occur during wet weather.

For properties built before 2002 consider replacing the existing consumer unit with a dual split-load consumer unit together with a Surge Protection Device (SPD). By splitting the sub-circuits, electricity will always be present in part of the property if one of the RCDs trips out. An SPD provides protection for the whole house against over-voltage spikes, an occurrence notorious with the Spanish electricity supply.

It’s also a good idea to fit an emergency light fitting with a self contained battery above the consumer unit, especially if it is located in a darkened area. In the event of a power cut the light automatically switches on - so no more fumbling round for a torch in the dark.