Household wiring comes together in consumer units, junction boxes and control cabinets. Over the years dust and cobwebs build up, condensation forms, contacts oxidise and overheated connections darken. All of this leads to outages, arcing and, at worst, fire.
In Ukraine the problem is especially noticeable in damp cellars, garages, boiler rooms and houses left unheated for long periods in winter. With generators and backup power now common, there are even more contacts and changeover switches to look after. Here is what you can do yourself and what to leave to an electrician.
What you will need
- WD-40 Specialist Contact Cleaner for contacts and terminals
- powerful vacuum cleaner with a narrow nozzle (no metal tip)
- dry soft brush with a non-metal ferrule
- torch
- insulated gloves and safety glasses
- dehumidifier or moisture absorber (if needed)
Important: Only work with the supply completely isolated: switch off the main switch and confirm there is no voltage with a tester. If you are not qualified, limit yourself to inspection and dust removal, and leave repairs, retightening terminals and replacing cables to an electrician. Never treat live contacts.
Step 1
Isolate and inspect the unit
Switch off the main switch, confirm with a tester that there is no voltage and open the cover. Inspect everything with a torch: condensation or traces of water, dust on breakers and terminals, cobwebs. Look closely at incoming and outgoing cables: darkened, melted or hardened insulation and blackened terminals mean overheating. If you find this, stop and call an electrician.
Step 2
Remove the dust
Dust does more than clog the mechanisms of breakers and switches: when damp, it conducts and can bridge contacts. Brush it off gently and vacuum it up straight away. Be especially thorough in boiler rooms, garages and workshops, where dust builds up quickly.
Step 3
Treat damp and oxidised contacts
If terminals, cable lugs or relay contacts show moisture or oxide deposits, spray them with WD-40 Specialist Contact Cleaner. It dissolves condensation, dirt and oxide, penetrates hard-to-reach spots, evaporates quickly without residue and is safe on most plastics. The thin straw lets you target the contact without flooding the whole unit.
Step 4
Let it dry and check
Wait a few minutes for the cleaner to evaporate completely. Make sure the inside is dry, there are no drops on the cover and all covers and blanking plates are in place. Only then close the unit and restore the supply.
Step 5
Deal with the source of damp
Treating the contacts removes the symptom, but the moisture must go too. Ventilate the recess or cabinet, or install a dehumidifier or a moisture-absorbing tub (replaced regularly). If the wall itself is damp, consider relocating the unit or fitting an enclosure with a higher protection rating.
Step 6
Look after sockets, switches and equipment
The same rules apply to junction boxes, sockets and switches in bathrooms and kitchens, and to generator connectors and changeover switches. Isolate the circuit, remove the cover, clear the dust and treat oxidised contacts with contact cleaner. Outer metal housings and fixings in damp rooms can be protected from rust with a thin coat of WD-40 Multi-Use, keeping it away from live parts.
Tip: Check a portable generator and its connectors before every outage season: plug and socket contacts left for months in a damp garage are the most likely to arc under load.
What next
Inspect the consumer unit once a year, and every six months in damp cellars, garages and boiler rooms. At the first smell of burning insulation, buzzing or warm breakers, isolate the circuit at once and call an electrician. For routine contact care, keep WD-40 Specialist Contact Cleaner to hand.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
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