When I plug in a Socket tester, which has a N light, PE light and a L light, into my Bluetti AC180. I get a PE light on only. When it says for Okay it should have a light on on PE and N. I tried this because when I plug the AC180 into my motorhome 240v socket I get a reverse polarity light on my mains power unit inside the motorhome. Is thios a fault ? Everything still works on 240v? AC180 in the UK. Dave