What is this?
Problems that begin after an EV charger installation may be caused by the installation itself — incorrect wiring, undersized cables, inadequate consumer unit capacity, or missing protective devices. A properly installed EV charger should not affect the rest of your electrical system.
Common causes
- Consumer unit overloaded — insufficient spare capacity for a 32A charger
- Incorrect or missing RCD/RCBO protection
- Undersized cable between the consumer unit and the charger
- Earth bonding not correctly completed
- Charger not configured correctly for the supply
- Surge protection not fitted as required by BS 7671
Is it dangerous?
Installation faults can be a genuine safety risk. Incorrect wiring, missing earth bonding, or inadequate protection could create shock or fire hazards. If your electrics are tripping since the installation, other circuits are affected, or you notice warm cables or burning smells, treat this as urgent.
Can I fix it myself?
You cannot and should not attempt to fix installation faults yourself. EV charger installation must comply with BS 7671 (IET Wiring Regulations) and Part P of the Building Regulations. Check that you received an electrical installation certificate from the installer and that they were an OZEV-approved installer.
When to call an electrician
Call an electrician (ideally not the original installer if you suspect their work is at fault) if the EV charger trips your main electrics, if other circuits have been affected since installation, if the charger cable or consumer unit feels warm, if you did not receive an installation certificate, or if the charger has never worked correctly since installation.
What will an electrician do?
Inspect the EV charger installation against BS 7671 requirements
Test the circuit for correct protection (RCD type, MCB rating, surge protection)
Check cable sizing and voltage drop under load
Verify earth bonding and protective conductor integrity
Rectify any non-compliant aspects of the installation
Issue a new electrical installation certificate if remedial work is done
Typical cost
£100 – £400
Inspection and minor corrections are at the lower end. If the consumer unit needs upgrading, additional RCBOs fitted, or cables replaced, costs increase. You may have a claim against the original installer if their work was non-compliant.
