travel trailer electric power

Thanks for that reminder. I DO have a plug-in volt meter in an outlet at counter level under my "control center" and watch that perhaps closer than I watch the amp meter. You can watch that and actually "see" the hot water heater cut on.

sometimes we will have lower voltage without the AC running due to CG issues. Usually the more crowded the campground, the lower the voltage. One of the reasons we like to camp during the week.

And as you imply, lower voltage means higher amps on each load. It is all a balancing act that you have to keep an eye on.

TundraTower wrote:
However, a public utility electrician showed me a trick a few years ago that I have added to my trailer to help the situation. He used an extension cord from the 15 amp pedestal thru the seal of his slide to run single larger loads.

Not that this can lead to low voltage though, depending on how the CG was wired and how old it is. The code does not provide for both a 30 and 20 amp recept. operating simultaneously. Low voltage (below 105) will damage AC units. They may seem to be starting and running okay but can be suffering irreversible and cumulative damage. You want a permanent voltmeter inside, either plug-in or hardwired to keep an eye on the voltage. Older CGs can be bad for low voltage.

As others point out, you just can't run everything in the trailer at the same time, and some of the bigger loads are not obvious like the water heater. We have to shut off the A/C to cook breakfast. Our stand-alone fault detector at the pedestal has a digital amp meter, and it is fascinating to watch that thing as things are turned on and off.

However, a public utility electrician showed me a trick a few years ago that I have added to my trailer to help the situation. He used an extension cord from the 15 amp pedestal thru the seal of his slide to run single larger loads.

I took this a step further and found a way to establish a permanent connection on the outside, with permanent wiring to two outlets, one in the bathroom and one near the dinette. These two outlets only work on this supplemental power from the pedestal, but sufficient to run a hairdryer or the coffee pot without having to turn off the A/C.

I've tried running the hot water heater on gas, but that thing is scary - Sounds like a blast furnace when you stand next to it. no way could I sleep with that thing energized. Sometimes we just have to wait for the water to heat up when we need it.

ktmrfs wrote:
Coffee, toaster on a single 15A breaker is really likely to end up tripping the 15A breaker. each could easily draw around 12A. quickly will trip a 15A breaker.

Sorry, but that's not true... Any molded case circuit breaker (like in houses and RVs) will continue to operate indefinitely at it's rating. You should be able to run 1800 watts continuously without a problem and if the 15 amp breaker does trip, it's faulty. And that is *IF* there is 120 volts at the appliances (that is it's rated operating voltage as per the label) and often the voltage is less, and sometimes a lot less like below 110 volts.

The other thing to know is that breakers do NOT trip as soon as they hit their rating. The have an inverse -time current characteristic as shown in this industry standard tripping characteristic graph. The time at which they trip depends on how much the current is over it's rating and for how long. The shaded area is the min. & max trip times. You could for example have 20 amps on a 15 amp breaker run for 1 to 5 minutes before it trips, or 17 amps would run for at least 2 min. and maybe not trip at all. The graph is showing that current twice a breaker's rating would continue to run for between 9 & 35 seconds before tripping (yellow line).

In most cases, the short duration of a toaster or coffee maker won't trip a breaker if it causes a slight overage on a breaker. And except for AC units, the lower the CG voltage is, the appliances will draw less current and it's even less likely a breaker will trip.

If you have a good stable voltage at home or elsewhere, try plugging in say 2000 watts total (16.7 amps) on a 15 amp circuit and see if the breaker trips. It should not trip before approx. 3 min., if it trips at all.

This is all assuming your SCD RV receptacle(s) was wired correctly at the factory... :)

It all adds up... Just like weight.... ;) A little here, a little there... Next thing you know, it's overweight or popping breakers.. :)

Mitch

Bobbo wrote:

afidel wrote:
Not picking on you but why do people keep mentioning the fridge? When it's cycling my 6.4 fridge draws a whopping 50W, less than half an Amp. The water heater I can see being a huge deal if running on electric or in electric boost mode, heating 6 gallons of water takes a ton of energy.

Because, when the fridge is on electric and is actively cooling, it is running a high wattage heating element to vaporize the ammonia. It can easily draw 10 amps at 120v, or 1200W. If yours can heat a heating element on 50W, you should buy stock in that company.

You're saying a 3 way fridge needs 100A to run, pure BS. I've actually measured my fridge with a killawatt meter, 50W when on high power, this was after pre-cooling but I always do that at home. The heating element on my fridge is rated at 300W max so I guess it could draw 2.7A at 'cold' start (ie just starting up) but like I said I measured mine in actual operation at 50W.

Bobbo wrote:

afidel wrote:
Not picking on you but why do people keep mentioning the fridge? When it's cycling my 6.4 fridge draws a whopping 50W, less than half an Amp. The water heater I can see being a huge deal if running on electric or in electric boost mode, heating 6 gallons of water takes a ton of energy.

Because, when the fridge is on electric and is actively cooling, it is running a high wattage heating element to vaporize the ammonia. It can easily draw 10 amps at 120v, or 1200W. If yours can heat a heating element on 50W, you should buy stock in that company.

well, I believe neither is correct. the heating element for a fridge is on the order of 300W, or 3A on most RV fridges.

2112 wrote:

ktmrfs wrote:

IMHO with a 30A service you can reliably have ONE of the following on at any one time.

AC
microwave
household toaster
household coffee maker
household hair dryer
HWW electric element
portable electric heater on high

I have found I can run any two of the above. Any third will trip the breaker.

I agree with 2112 if you add converter/charger if the batteries are low, and fridge.

ktmrfs wrote:

IMHO with a 30A service you can reliably have ONE of the following on at any one time.

AC
microwave
household toaster
household coffee maker
household hair dryer
HWW electric element
portable electric heater on high

I have found I can run any two of the above. Any third will trip the breaker.

afidel wrote:
Not picking on you but why do people keep mentioning the fridge? When it's cycling my 6.4 fridge draws a whopping 50W, less than half an Amp. The water heater I can see being a huge deal if running on electric or in electric boost mode, heating 6 gallons of water takes a ton of energy.

Because, when the fridge is on electric and is actively cooling, it is running a high wattage heating element to vaporize the ammonia. It can easily draw 10 amps at 120v, or 1200W. If yours can heat a heating element on 50W, you should buy stock in that company.