EV Charger Electrical Safety Testing: What Inspectors Check and Why It Matters
An EV charger draws more power than almost any other single appliance in a home or commercial building. A 7 kW wallbox pulls roughly the same current as an electric shower running continuously for hours. A 22 kW three-phase unit draws considerably more. That sustained high-current load places demands on your electrical installation that periodic inspection and testing must verify are being met safely.
When your property has an EICR inspection, the EV charger circuit receives specific attention. The charger itself, the cable feeding it, the protective devices in the consumer unit, the earthing arrangements and the physical condition of the installation are all examined and tested. Faults in any of these areas can create fire risks, electric shock hazards or equipment damage.
This guide explains exactly what inspectors check when testing EV charger installations, the common faults we find across Manchester properties, and what you can do to keep your installation safe between inspections.
Why EV Chargers Need Specific Testing Attention
Standard domestic circuits — lighting, socket outlets, cookers — are designed for intermittent use. You switch on a kettle for three minutes, run the washing machine for an hour, turn lights on and off throughout the day. An EV charger is different. It draws near-maximum current for extended periods, often several hours at a time, potentially every day.
This sustained loading accelerates wear on cables, connections and protective devices. A loose terminal that causes no problem on a lightly loaded socket circuit can overheat significantly when carrying 32 amps continuously for eight hours. Cable insulation that is adequate for occasional use may degrade faster under sustained thermal stress.
The other factor is location. Many EV chargers are installed outdoors or in garages — environments with moisture, temperature variation and physical exposure that indoor circuits do not face. These environmental factors increase the importance of proper installation and regular inspection.
What Inspectors Test: The Full Checklist
Circuit Protection Devices
Every EV charger circuit must have appropriate overcurrent protection, typically a dedicated circuit breaker in the consumer unit rated to match the cable and charger specification. For a standard 7 kW single-phase charger, this is usually a 32 A Type C MCB.
The inspector verifies that the circuit breaker is correctly rated for the cable and charger, that it operates within its designed tripping characteristics, that there are no signs of overheating or discolouration on the device or its connections, and that the device has not been incorrectly replaced with a higher rating to stop nuisance tripping — a dangerous practice that removes the cable's protection.
RCD Protection
EV charger circuits require RCD (Residual Current Device) protection to guard against electric shock from earth faults. The specific requirements depend on the charger type and installation date, but generally an EV charger circuit needs Type A RCD protection as a minimum, with many installations requiring Type B or Type EV protection.
Type A RCDs detect AC earth fault currents. Type B and Type EV RCDs also detect DC earth fault currents, which can be generated by the charger's internal electronics. If a DC fault current occurs and the RCD cannot detect it, the protection is ineffective and the installation is unsafe.
The inspector tests the RCD by injecting a test current and verifying that it trips within the required time — 300 milliseconds at rated current, 40 milliseconds at five times rated current. They also check the RCD type matches the installation requirements and that any DC fault detection built into the charger is functional.
Earthing and Bonding
Proper earthing is critical for EV charger safety. The charger's exposed metalwork must be connected to the installation's earth so that a fault diverts current safely rather than energising the charger casing. The earth path must have sufficiently low impedance to ensure that the protective device operates quickly enough to prevent injury.
The inspector measures the earth fault loop impedance at the charger location. If this value is too high, the circuit breaker may not trip quickly enough during a fault, leaving dangerous voltages on accessible metalwork. High earth loop impedance is one of the most common issues we find on EV charger circuits in Manchester, particularly on older properties where the earthing system was not designed for the additional circuits now connected to it.
Supplementary bonding may also be required depending on the charger location and the property's earthing system. If the charger is in a garage with metallic pipework, structural steel or other extraneous conductive parts, these must be bonded to the installation earth.
Cable Condition and Routing
The cable feeding the EV charger is inspected along its entire route from the consumer unit to the charger. The inspector checks for physical damage — cuts, abrasion, crushing, rodent damage, cable degradation from UV exposure on outdoor sections, and any signs of overheating at terminations.
Cable sizing is verified against the circuit's design parameters, accounting for the cable route, grouping with other cables, ambient temperature and thermal insulation. A cable that was correctly sized at installation can become inadequate if additional cables are later run alongside it, increasing the grouping factor and reducing its current-carrying capacity.
The method of cable support and containment is also assessed. Cables should be properly clipped, supported or run in trunking. Cables left unsupported, running across surfaces without fixings, or routed through areas where they could be damaged are recorded as defects.
Charger Unit Condition
The charger unit itself is visually inspected for damage, water ingress, discolouration from overheating, and integrity of the enclosure. The IP rating of the enclosure is checked against the installation location — an outdoor charger needs at least IP65 to protect against water and dust ingress.
The charging cable and connector are inspected for wear, damage to insulation, bent or corroded pins, and proper locking mechanism operation. The earthing connection to the charger's metalwork is verified.
If the charger has a built-in DC fault detection device (as many modern units do in lieu of a separate Type B RCD), the inspector may test this function to confirm it is operational.
Isolation and Switching
The installation must have a means of isolation that allows the EV charger circuit to be safely disconnected for maintenance or in an emergency. This is typically the circuit breaker in the consumer unit, but some installations also include a local isolator adjacent to the charger.
The inspector verifies that isolation devices are accessible, correctly labelled, and functional. In commercial installations, the isolation arrangements must comply with the Electricity at Work Regulations and allow a safe system of work for maintenance.
Common Faults Found on EV Charger Installations
Based on our inspection work across Greater Manchester, these are the most frequent issues we identify on EV charger circuits.
Incorrect RCD Type
Many older EV charger installations were fitted with standard Type A RCDs when the charger specification requires Type B or Type EV protection. This is particularly common on chargers installed before 2020, when awareness of DC fault current risks was lower. The charger appears to work normally, but in certain fault conditions the RCD would not operate, leaving the installation unsafe.
Rectifying this requires replacing the RCD or installing a Type B RCBO on the circuit. Typical cost for this remedial work is £200 to £450 depending on the consumer unit configuration.
Deteriorated Outdoor Cables
Cables routed externally without adequate UV protection degrade over time. The outer sheath becomes brittle and cracks, exposing the inner insulation to moisture. This is a common finding on installations where standard PVC cable was used for outdoor sections instead of UV-resistant cable or cable run in conduit.
Loose Terminations
The sustained high-current loading on EV charger circuits makes loose connections more dangerous than on lightly loaded circuits. A connection that is not properly tightened generates heat under load. Over months or years of daily charging, this can char insulation, damage terminals and in extreme cases cause fires.
We find loose terminations most frequently at the consumer unit end of the circuit, at junction points where cable routes change, and at the charger's own terminal block. Thermal imaging during inspection can identify hot spots before visible damage occurs.
Inadequate Earthing on Older Properties
Properties with TT earthing systems — common in rural and semi-rural areas around Greater Manchester — sometimes have earth electrode resistance values that are too high for adequate protection of EV charger circuits. The earth fault loop impedance exceeds the maximum value needed for the protective device to operate within the required disconnection time.
Properties with older TN-C-S (PME) earthing may also present issues if the main earthing terminal or bonding conductors are undersized or corroded.
Missing or Incorrect Labelling
Consumer unit schedules should identify the EV charger circuit and its protective devices. We frequently find EV charger circuits that were added without updating the circuit schedule, or labelled generically as "spare" or "garage" with no indication that they supply an EV charger. This creates safety risks during fault-finding and maintenance.
How Often Should EV Charger Circuits Be Tested
The standard EICR frequency applies to EV charger circuits as part of the overall fixed electrical installation. For residential properties, this means every 10 years for owner-occupied homes (5 years recommended), every 5 years for rented properties, and for commercial properties every 5 years as standard.
However, the sustained loading and environmental exposure of EV charger installations means that more frequent visual inspection is advisable. An annual visual check of the cable route, charger condition, and connection integrity can identify developing issues before they become serious faults.
For commercial installations with multiple chargers — car parks, depots, workplace charging — a more frequent inspection regime may be appropriate, particularly in the first year of operation when installation quality is being proven under real-world conditions.
What to Do If Your EV Charger Fails an EICR
If an EICR identifies faults on your EV charger circuit, the report will categorise them using the standard classification codes. C1 faults represent immediate danger and the charger should not be used until the fault is rectified. C2 faults are potentially dangerous and should be fixed within 28 days. C3 observations are recommendations for improvement.
For C1 faults — which are thankfully rare on EV charger circuits — the inspector may isolate the circuit during the inspection to remove the immediate danger. Do not reconnect the charger until qualified remedial work has been completed and certified.
For C2 faults, arrange remedial work promptly. The most common C2 faults on EV charger circuits are incorrect RCD type and deteriorated cables, both of which are straightforward to rectify with a qualified electrician.
After remedial work is completed, a re-inspection of the affected circuit confirms the faults have been properly addressed and the installation is safe. This re-inspection should be carried out by the same electrician or company that performed the EICR.
Keeping Your EV Charger Installation Safe
Between formal inspections, there are practical steps you can take to maintain your EV charger installation in safe condition. Check the charging cable regularly for cuts, cracks or damage. Ensure the charger enclosure is intact and the door or cover closes properly. Listen for unusual buzzing or clicking sounds during charging. Feel the cable near the charger and near the consumer unit during charging — it should be warm but not hot. Test the RCD using the charger's built-in test button monthly. Keep the area around the charger clear of combustible materials. Report any tripping, intermittent charging or error codes promptly.
Professional EV Charger Testing in Manchester
We carry out EICR inspections and specific EV charger safety testing across Greater Manchester. Whether your charger was installed last month or five years ago, a professional inspection gives you confidence that the installation is safe, compliant and properly protected.
Call us on 0161 312 2240 or email hello@manchestercompliance.co.uk to book an inspection. We cover all areas of Greater Manchester including Manchester city centre, Salford, Stockport, Oldham, Tameside and Rochdale, with same-week appointments available.