Originally Posted by tgduffy
Can I use a portable 120v electric heater when hooked up to city power instead of using my trailer heater and using up propane? The portable has 2 settings, 800 watts and 1100 watts. I'm not an electrician but I know these little puppies pull some serious juice. Is it safe? Will I blow a fuse?
If you are going to RV much, then it's easy to learn this basic formula quickly to understand what you can have on, and what must be turned off to not over load circuits/power supplies.
It's real simple math:
Watts = volts X amps or you also figure it as amps = watts/volts
Since you are almost always going to be using 120 volts, that is simple enough.
Take your 800 watt heater/120 volts = 6.67 amps
1100 watts/120 volts = 9.17 amps
Since most RV circuits that your outlets are on are wired for a 15 amp breaker, then that lets you know how many amps your heater is pulling and you are below the 15 amps. However you need to add up everythng that is on that circuit (possibly television, other things plugged in, etc)
Also you need to kinda know what all the appliances in your RV pull (air conditioner, microwave, water heater on electric, fridge on electric, etc) so you don't overload your main breaker or individual circuit breakers by having too much on.
It's a learning process, that we all go thru....and thus learn what can be on...and what also must be off at the same time to not trip circuit breakers.
Now that you know how to do the math, you can look at the tags on electrical things if you don't know the wattage and see how many amps it needs.
These links may help out too:
Basic RV Electricity - RV Information (RV Maintenance)
RV Converters and Amp Draw - RV Information (RV Maintenance)