Consumer unit installation in Batumi: a turnkey unit for your apartment

What consumer unit installation in Batumi includes

For us, consumer unit installation in Batumi starts with a list of your appliances and the rating of the main breaker. The consumer unit (fuse box) divides the power allocated to the apartment between the circuits and disconnects the one where something has gone wrong. A typical 24–36 module unit holds these devices:

When a relay is enough and when you also need a stabiliser and an SPD is explained on the page about protecting appliances from voltage surges.

Calculations before the devices are bought

How to add up the power of your appliances and stay within the allocated capacity is shown on the page about apartment electrics. For the consumer unit, three rules follow from it:

• the main breaker is rated no higher than the apartment is allowed. If it trips in the evenings, the load is redistributed rather than a bigger breaker fitted: the cable from the floor distribution board is not designed for that;
• a circuit breaker protects the cable, not the appliance, and its rating depends on the cross-section of the conductor. Without replacing the cable, the rating is not raised;
• an RCD is rated no lower than the breaker in front of it, because that breaker is what protects the RCD from overload.

If the total is still above the allocated capacity, besides applying for a capacity increase there is a load-shedding relay, which switches off the water heater while the hob is on. The circuits to the consumer unit are run during the apartment electrical installation, and both jobs work from the same circuit layout. Where to put the consumer unit and when to plan a recess for it is covered on the page about rough renovation.

How we divide the circuits into groups

By a group we mean an RCD and the circuit breakers that sit behind it. In a one-bedroom (1+1) apartment with an air conditioner in every room, the groups are usually as follows:

• lighting for the rooms and hallway, separate from the sockets, so that a leak in a socket doesn’t leave the apartment in the dark;
• room sockets through a shared RCD, with one breaker for every one or two rooms;
• kitchen: the worktop sockets, the hob, the oven and the dishwasher on their own breakers;
• bathroom: the washing machine and water heater on their own RCBOs, plus the heated towel rail and underfloor heating;
• each air conditioner on its own circuit;
• the balcony separately and always through an RCD.

How we assemble the consumer unit and what you can check at handover

Assembly mistakes usually show straight away. At handover, including over video, check the following:

• each RCD group has its own neutral. If the neutral of one circuit is taken to the busbar of a neighbouring group, the unit still works, but the RCD trips when the lights or the kettle are switched on;
• stranded wire has a ferrule, there is one wire under each screw, and the breakers are linked with a comb busbar rather than loops made from cable offcuts;
• the SPD usually sits before the RCD in the direction of current flow, so that the spike goes to earth without passing through the RCD and doesn’t trip it. Our engineer chooses the layout to suit the building’s earthing system;
• every device is labelled, empty ways are closed with blanking plates, and the “Test” button on an RCD switches off only its own group.

We tighten the terminals to the torque given in the device’s data sheet: an under-tightened screw on an air conditioner circuit heats up under load and eventually burns.

Testing before handover

Before the power is switched on for the first time, we test the insulation of each circuit from its breaker once more: this shows whether a conductor was nicked when it was brought into the unit. Then we switch the circuits on one at a time under load.

The “Test” button only shows that the RCD mechanism works, not at what current it trips or how quickly. So we check every RCD and RCBO with a tester, and the figures go into the test report. After an hour under load, we use a pyrometer (an infrared thermometer) to check whether the terminals of the main breaker and the air conditioner circuits are heating up.

We set the relay thresholds and delay to suit the apartment’s appliances and record them in the handover file, and the circuit diagram is stuck on the consumer unit door. It is used later for apartment maintenance as well.

The developer’s consumer unit: add to it or replace it

In a white frame apartment the developer often fits a small box: a main breaker, a couple of breakers for the lights and sockets, and sometimes one RCD for the whole apartment. That is not enough for living with air conditioners, an induction hob and a water heater.

If the box has room and the devices are sound and correctly rated, we add to the unit: a relay, RCDs for the wet areas and breakers for the new circuits. If there is no room, we replace the whole box and move into the new one whatever can be kept.

How much consumer unit installation in Batumi costs

A turnkey apartment consumer unit costs from 1,740 to 2,400 ₾. This price includes the equipment: the enclosure, main breaker, circuit breakers, RCDs and voltage protection relay, plus assembly, connection and testing. If you buy the devices yourself, assembling and connecting a 24–36 module unit costs from 540 to 780 ₾ for the labour.

The price depends on the number of circuits and how they are protected. Each extra RCD or RCBO, installed, adds 220–265 ₾, a surge protection device, installed, 300–420 ₾, and fitting one more circuit breaker in a finished unit 29–48 ₾ for the labour.

The final cost is set after an inspection of the incoming supply and once the estimate is agreed. We fix the price of the stage in the contract, and it doesn’t go up unless the scope changes.