Energy Management In An All Electric Coach

[Wild Willy]

We've been living in our all-electric Ventana with 3 roof ACs for about 2 months now, and I'll have to say, a 50-amp service just doesn't cut it when it's a 100 degrees outside. We really have to watch our energy use so the main breaker doesn't trip. We've been using our portable EMS, and it has been working great except for the many high-frequency errors we've been getting. I talked with the RV park, the power provider, and Progressive Industries about it, and I think I may have found the answer. I put a piece of tape over the photo cell on the pedestal - which has a fluorescent light - and that seems to have done the trick.

Anyway, I've been working on adding up how many amps each of our appliances use, and we really have to be careful about when we do laundry, when we use the convection oven, and even when we use the central vacuum I recently discovered. Right now, we have the middle AC unit turned off. We can keep the coach at 80 during the day with 2 ACs, but it takes a while to cool it down to our comfy 74 when we get home in the evening. I know this won't be as big of a problem when the weather cools a bit, but it's a pain right now.

Here's what I've been able to determine so far:

-Each AC unit uses about 14 amps - a bit more upon start up. With all 3 running, that's 42 of the total 50 amps available.
-AC1 water heater: 11 amps (L2)
-AC1&2 water heater: 13 amps on L1 and 11 amps on L2 for a total of 24 amps, but we've never had to use AC1&2. AC1 puts out enough hot water since the incoming water temp is pretty warm. We've recently discovered the burner on the Oasis since we're having to watch usage. It uses less than 1 amp, gets the water super hot super quick, but makes a little noise. Not a huge deal though.
-Dryer: 12 amps - a bit more upon start up.
-Washer: about 2 amps
-Convection oven: 10 amps
-Fridge??
-Central vac??
-??

I know all of this can be found in the manuals, but I wanted to see what they actually read on the power control panel.

With all of the above off (including lights and TVs off), I'm still using about 6 amps somewhere. I tried turning off the fridge, but it really didn't make any difference on the display. Does anybody know where those 5-7 amps are coming from? I'd love to hear from anyone out there if they've had similar experiences. I can't imagine the satellite control, coffee maker, lights (which run on DC), TVs, etc. pull much power.

Our RV park charges for electrical usage, and our bill for July was $150. I really didn't think it would be that much, but the ACs are running pretty much all the time (less at night of course).

Anyway, your thoughts on other sources of phantom usage would be appreciated - or how you might manage your power better than I.

Here's another question for you: We're building our new house right now with an RV garage. Can I have my electrician put a 60-amp breaker with big enough wire to supply 60 amps to the coach? I noticed on the Magnum that the shore max is set to 50 amps. Could you increase that to 60 and be able to use more appliances at the same time?

[96 Wideglide]

If your plugged into a 'true' 50A RV outlet, you have 100A available !

[Dutch Star Don]

You should be able to run EVERYTHING on 50 amps. You say the main breaker is tripping....are you talking about the coach or the pedestal. If it's the pedestal, the breaker is probably old/bad. As stated by "96 WIdeglide" and many don't understand, is that when you're connected to 50 amps, it's 50 amps on each of your two main branches for 100 amps total. When you're on 30 amps, it's only 30 amps.

You need to figure out what's wrong, most likely with the pedestal breaker.

[Selah]

Although it is called 50 amp service it is in reality two 50 amp feeds. That's 50 amp on L1 and 50 amp on L2 for a total of 100 amps available to your coach.
Three ACs, water heater, microwave, hair dryer, central vac, all TVs running at the same time should not be tripping the breaker.
Check the voltage that your EMS is showing on each leg. Low voltage will trip the breaker.

[Monfish]

Some of your "missing amps" might be attributable to the battery charger. We have found some RV parks (even nice ones) have weak breakers which tend to trip under heavy load even if the load is within their rated capacity. A friend who is a master electrician told me that is not uncommon. I have also hear that breakers which are frequently turned on and off weaken faster because they are not designed for that purpose. We have had good luck with asking the park to change our breaker.

[cc8375]

When it's Hot..... we find it's could to get a Good start on the AC. In the mornings you can hang meat in the RV. But this helps keeping it cool in mid afternoon.

We camp in state parks with only 30 amps. To eliminate a AC cutting off, I will run on batteries during the day. The AC is the Only draw on the power pedestal.

At night I turn the Inverter back on to Charge the batteries. Dryer/ washer use and in the late / overnight for Electric Hot water.

Yes, breakers have a spring in them that becomes weak. Breakers are turned on and off by Rvers and they were not designed to be a on / off switch.

[Mr_D]

50 amp RV service gives 12,000 watts 50 X 120 X 2 = 12,000
30 amp RV service gives 3,600 watts 30 X 120 = 3,600

[PDR John]

Sunday it was 100 here and we really pushed the coach.

All 3 ACs

Dishwasher

Oven

Stove top

Single burner on the Oasis

Washing machine

Along with all the normal coach items running. When I checked usage we were pulling 45 amps on one leg and 36 on the other, EMS would shut down the front AC on occasion. The coach still didn't get above 80 inside.

Has soon as the oven got done it cooled back down to 74. Noway our old coach could have even come close.

[redbaron73]

I agree with PDR John. To add to his usage, we have 4 kids constantly coming and going in and out all day. The ability of the coach to recover and maintain a decent air temp beats all my expectations.

I have had occasion where the generator did not provide enough for all devices and had to shut down the oasis electric or one ac, but that was with laundry, microwave, etc all running.


2013 Newmar Dutchstar 4347, Active Air

[tbbg II]

My guess is the coach has too many circuits on one side of the 240VAC input (not necessarily one side of the breaker panel as the input is staggered). As others have said the 50 amp is enough, but if you get 55 amps on one side, it will trip both sides of the breaker. It is fairly easy to check. If you are familiar with breaker boxes you can tell within minutes. Then simply moving a breaker or two and you should be back in business. If you are not comfortable with opening the box, an electrician should be able to resolve in less than an hour.

[Wild Willy]

I love this forum - you guys are such a wealth of knowledge, and I thank you all very much for your input. Electrical knowledge has been a weakness of mine, but is becoming a strength.

I had a long conversation with my electrician today, and he really didn't understand what was going on because he was assuming my ACs and dryer were 240-volt appliances. Now that I know they are all 120, the whole thing makes much more sense.

Interesting timing on the current issue of Motorhome magazine. Great article on page 99 called Power Trip 101 that pretty much echoed what all of you said in your posts. Now I understand phasing much better - and why I'm able to get 100 amps to my coach instead of just 50. Pretty cool stuff.

On the high frequency error shutdowns from my EMS, I haven't had it happen since I put a piece of tape over the pedestal's photo cell that controls the fluorescent light on it. I do think the pedestal breaker needs to be replaced, and I'll be begging the RV park to do that in the next day or two. I've noticed that my shore cord plug head has gotten really hot lately. It's super hot outside, but I think low voltage has caused a lot of that heat - I've seen it go as low as 120 volts, but the EMS hasn't shut down due to low voltage yet.

The whole power subject is fascinating to me, and I'll have more questions later, but maybe someone can help me with a question on my central monitor panel. First, is the middle button not used? Second, on the load status, my block heater always shows as on, but I know for a fact it's unplugged. And water heater 1 and 2 always show as on (we've only been using water heater 1), and all 3 lines show 0 amps. On the next screen, all 3 A/Cs show as ON and 0Amps. Is mine broken, not hooked up, or what?

[KenNJ]

Will,

What I was told on my Ventana was that those items you mention in your last paragraph only become active readings when you are running on the generator and not shore power. On mine, I tested it and found it to be true.

[spinn]

Wild W, if the power cord is getting extremely hot you might want to monitor the line voltages of both legs at the pedestal. If a park is full and the day very hot it is not unusual for voltage at the park to drop. Your EMS should shut you down if voltage levels drop too low (108 or so). This is to protect your electronic devices which are very sensitive to low voltages
S

[PDR John]

Originally Posted by Wild Willy

The whole power subject is fascinating to me, and I'll have more questions later, but maybe someone can help me with a question on my central monitor panel. First, is the middle button not used? Second, on the load status, my block heater always shows as on, but I know for a fact it's unplugged. And water heater 1 and 2 always show as on (we've only been using water heater 1), and all 3 lines show 0 amps. On the next screen, all 3 A/Cs show as ON and 0Amps. Is mine broken, not hooked up, or what?

I'll have to get home to answer about the middle button.

The reason all that stuff shows on and 0 amps is because EMS hasn't shut any of it down.

Unplug from your 50 and re plug into the 30 amp outlet. Turn everything back, it won't trip the breaker, then see what all it reads. Things will show off and the amps they pulled when shut down. You will also be very surprised at what all can be run on only 30 amps.