i have just obtained a caravan with a xp-compact xpc 2200-24 studer inverter, it seems to be newly installed. my problem is when i turn it on it will cut out completely after say 30 seconds, i have also pluged my outside power supply in and it does not seem to be taking in a charge? there are two very large battery's connected to this system . i cannot seem to get this system working could you please help. ps an alarm goes off from time to time also.