EV Charger Installation Guide: AC vs DC, kW, Connectors & Safety

AC chargers send alternating current to the car and let the vehicle's on-board charger convert it to DC, while DC fast chargers do the conversion inside the charger and feed the battery directly — which is why DC is much faster.

Because an AC charger's speed is limited by the car's on-board charger, a 22 kW AC point will still only charge a car at, say, 7.2 kW if that is all its on-board charger accepts. AC chargers are compact, affordable and ideal where vehicles are parked for hours: homes, offices, hotels. DC fast chargers are larger, need a much bigger supply and cost more, but can add substantial range in a short stop — which suits highways, fleet depots, malls and public hubs.

The kW rating tells you how much power the charger can deliver; charging time is roughly the battery capacity in kWh divided by the power actually accepted, plus some losses and slowdown near full.

Most electric cars sold in India use a Type 2 inlet for AC charging and a CCS2 inlet for DC fast charging; CCS2 is simply a Type 2 plug with two extra DC pins below it.

Many 2- and 3-wheelers charge from an industrial-style IEC 60309 socket or a standard socket through a portable charger supplied with the vehicle, so a dedicated, properly protected socket outlet is often all they need. Before choosing a charger, check your vehicle's manual for its inlet type and maximum AC and DC charging power — there's no benefit in paying for more power than the vehicle can accept.

The right setup depends on who uses the charger, how it's billed and how much supply is available.

At home, a wall-mounted 7.4 kW AC charger on a dedicated circuit from your own meter is the usual choice. In a housing society, chargers in the basement or parking are typically fed either from each resident's own meter or from a common supply with per-user billing through RFID or an app, and the society's total load must be assessed so many cars charging at night don't overload the transformer. Commercial and public sites — offices, hotels, malls, fleet depots — generally combine several AC points with one or more DC fast chargers, networked for payment, access control and monitoring.

Every EV charger installation should start with a load calculation, because a charger draws its full rated power continuously for hours — unlike most household appliances.

A 7.4 kW single-phase charger draws around 32 A, which may exceed the spare capacity of a typical home connection when ACs and a geyser are also running. The survey checks your sanctioned load, meter and main switch rating, cable sizes and DB capacity, and may recommend increasing the sanctioned load, moving to a three-phase supply, or using a charger with load management that reduces charging power when the house draws more. Larger commercial and public stations may need a separate connection or metering for EV charging from the local electricity distribution company; the applicable tariff and process are set by the distribution company and state regulator, so they should be confirmed at the planning stage.

OCPP (Open Charge Point Protocol) is an open communication standard that lets a charger talk to any compatible management software, so you are not locked into one vendor's app or platform.

With OCPP 1.6 and 4G, Wi-Fi or LAN connectivity, chargers can be monitored remotely, started by RFID card, QR code or app, billed per kWh using a Class 1 energy meter, and scheduled or load-balanced across multiple points. For a home charger, basic app control and scheduling are usually enough; for societies, workplaces and public stations, networked OCPP chargers are strongly recommended.

An EV charger must have its own dedicated circuit with correctly rated MCB, residual current protection and a sound earth connection — this is the most important safety part of the installation.

EV chargers are used outdoors, in wet basements and with a cable that people handle every day, so earth leakage protection is essential. Because a vehicle's charging electronics can produce smooth DC leakage current that ordinary AC-type RCCBs may not detect, chargers either include built-in DC leakage detection or are protected by an RCD type specified for EV use; the charger's manual should be followed. A dedicated earth pit, or a verified low-resistance connection to the building's earthing, is also important, along with surge protection for the charger's electronics.

In India, EV charging equipment is covered by the IS 17017 series of standards, which are aligned with the international IEC 61851 standards for conductive charging. The Central Electricity Authority's safety regulations include provisions for EV charging stations, and the Ministry of Power issues guidelines for public charging infrastructure.

For homes, this translates into a properly designed and protected dedicated circuit installed by a qualified electrician. For public stations, requirements such as connection approvals, metering, signage and safety clearances should be confirmed with the local distribution company before installation.

The best location is as close to the main DB or meter as practical, where the car's inlet can reach without stretching the cable.

Chargers need little maintenance, but regular checks prevent the most common failures.

Inspect the cable and gun for cuts, cracked housings or burnt pins, keep connectors clean and dry, test the RCD periodically using its test function, and have terminals tightened and earth resistance measured yearly. Call an electrician if the charger trips often, the plug or cable gets hot, you see discolouration or smell burning, or the charger shows earth-fault or communication errors.

Electrons designs, supplies, installs, tests and commissions EV charging across Zirakpur, Panchkula, Chandigarh and Mohali — from 3.3 kW AC points for 2- and 3-wheelers to CCS2 DC fast chargers for cars. We visit your site, carry out the load calculation, recommend the right charger and any panel or supply upgrades, install the dedicated circuit with proper earthing and protection, commission and test the charger, and offer maintenance contracts afterwards.