224v is really low for a nominal 240 volt feed, but we have seen posts here by others where that was what the neighborhood experienced. So, in their case, it wasn't a faulty installation, but rather a result of a weak infrastructure. But, it needs to be checked out to be sure that's what is going on.
What I would do is find another plug in the house and measure the voltage there before and during the car's charging. If the plug is a 120v variety, double what you measure. If you don't have a meter, just use an old-style (incandescent!) lamp. If the car's charging causes a similar drop in voltage (or dimming of the lamp) on that plug, the problem is outside of your house. Call the Electric company.
If the other outlet stays pretty stable, but the car still dips to 224v, call your electrician before serious damage is done.