What you haveare two 30Ampbreakers in series protecting yourtrailer. One 30Amp on the post and the 30Amp breaker in your trailer. My guess is that the 30Amp breaker had to be changed because it had tripped enough times that if you were pulling anything near 30 amps, it wasn't capable of maintaining a 30 amp load from your trailer. You must be cognisant of the load that you are putting on the post supply. The comment by the electrician is bogus because if you did what he suggested, then it would be your 30Amp breaker tripping and not the one on the post.
Here are typical loads of your appliances in the trailer. A/C -->15 to 18 Amps, Water heater ---> 10 to 12 Amps, Fridge ---> about 2 Amps, Converter---> 5 to 8 Amps. Let suppose that your loads are at the minumum of my guestimates. You've got the A/C going, the water heater is on electric, the fridge is on electric and ofcourse the converter is going all the time. If all the appliances happen to be on at the same time, there's going to be a 30Amp breaker trip somewhere, because your load is 15 + 10 + 2 + 5 = 32 Amps. If one of the appliances is not running and you fire up say the microwave and the DW puts on the electric kettle, then you're going to have a 30Amp breaker trip. When you only have 30 amps of electricity available, you need to substitute where possible (run on gas) and time share the service. eg. If one heavy load is going, don't fire up another heavy load, unless you want to sit in the dark.
Edited by: Hamops
Helen & George VE3INB and Max (Bichon Frise)
2006 Silverado 2500HD D/A,
2006 Cruiser CF30SK