Caution - take care when dealing with any 230V issues - Mains electricity is dangerous
I'm using my generator
It is quite common for the reverse polarity indicator to come on when using a generator. This is caused by the way many generators have the output wired, and although it can be disconcerting to see the reverse polarity light come on, in this situation it is quite normal and nothing to worry about, providing you press the 'TEST' button on the RCD and confirm it trips. If the RCD doesn't trip then you shouldn't use the 230V system and should consult a qualified electrician for advice.
I'm on mains hook-up outside the UK
In many countries outside the UK, for example most of Europe, they don't earth the Neutral in the supply network as we do in the UK. This means that they are not polarity conscious as we are in UK, with both conductors being considered 'Live', and so they use MCBs which break both conductors, unlike standard UK MCBs which only break the Live conductor. We fit all of our systems with MCBs which break both Live and Neutral and so keep the vehicle user safe in the event of a fault. The standard equipment fitted in the van will also be suitable for use on the continent, however if you are unsure if an item of equipment you plan to use in your van whilst abroad is safe to use you should contact the supplier / manufacturer for advice.
If the reverse polarity indicator comes on whilst outside the UK, then again it is usually safe, so long as the 'TEST' button operates as above. Some users carry a polarity reversing adaptor with them when travelling outside the UK which can be used to correct the polarity in the van.
I'm on mains hook-up in the UK
If the reverse polarity light comes on when on mains hook - up at a site in the UK, you should in the first instance contact the site warden to confirm the fault isn't with the site supply. Then you should have your hook-up lead inspected in case it is at fault - as a simple test you may be able to try a different lead. If you are unable to find a simple cause of the indicator coming on then you should have your 230V system checked by a qualified electrician.
The reverse polarity indicator briefly flashes when my charger turns on or off
When the charger is turned on or off the indicator may give a brief flash or short series of rapid flashes. This is just down to the components in the charger charging / discharging as power is connected / disconnected. This is quite normal and nothing to worry about.
The reverse polarity indicator comes on when I turn my charger on
In the majority of our systems, the reverse polarity indicator is only switched into circuit when the charger is turned on. We do this as it would interfere with readings taken when your electrical system is being given it's regular inspection. As the charger must also be turned off when tests are performed, the charger switch provides a safe and convenient way to disconnect them both for testing.