Most UK homes are supplied with a PME earth (also called TN-C-S), where the earth and neutral are combined in the supply cable. It works well for the house, but a rare fault in the supply neutral could put a dangerous voltage on the metalwork of a car connected to an outdoor charger. Wiring regulations therefore require extra protection for chargepoints on PME supplies.
There are two common ways to comply. Many modern chargers have built-in protection that detects the fault and disconnects the supply, so no additional earthing is required. Alternatively, the installer can fit a separate earth rod, which adds cost and needs suitable ground. Which route is right depends on the charger and your ground conditions.
That's why quotes can differ: one includes an earth rod, another uses a charger with built-in protection. It's worth asking your installer which method they plan to use and why. A reputable installer will explain it plainly.
If you'd like a like-for-like comparison, tell us about your home and preferred charger in the quote form and we'll help match you with an installer who can price it properly.
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