For want of 50 amps

[Monkeyman_and_L]

Had to change campgrounds for our final 2 days at the beach. The KOA had 50 amp service, this campground has 30.

Told spousal unit that 30 is what our other at home uses, and the coach stays plenty cold.

94 degrees, direct sun, not so much.

Guess we'll skip 30 amp sites in the summer from now on.
The power management system is doing what it's meant to do, but it keeps the bedroom as running and shuts down the main cabin, cycling every 3 to 5 minutes.

What else can I shut down to keep ac on long enough to cool coach down? thanks

[Rice]

jerseyjim wrote:
50 -30 AMPs....simple. Put the water heater on gas. Use only ONE a/c unit.

The problem the OP is having is that he IS using only one air conditioning unit, because that's what his power management system is allowing. But he wants to use both air conditioning units.

[Mile_High]

Of course you all will :R

[Gottahaveit]

AllegroD wrote:
I will gladly take Doug's opinion 99% of the time.

yep

[wolfe10]

AllegroD wrote:
I will gladly take Doug's opinion 99% of the time.

AMEN.

[AllegroD]

I will gladly take Doug's opinion 99% of the time.

[pianotuna]

Hi Doug,

I agree many RV'ers are not well informed.

I agree there are no "dumb" questions.

I don't agree that educating owners to use their equipment to its fullest potential is a mistake. Your post points out the glaring example of a residential fridge with an inverter left on. The owner needs to know the potential results.

There are exceptions to inverter off as a default--but I agree normally it should be off. I do have one that uses load support and I find that wonderful when limited to 15 amp shore power.

I do enjoy your posts and sometimes change mine based on your insights.

[dougrainer]

pianotuna wrote:
Hi doug,

1. If the inverter is on does draw a small amount of energy--not from the battery bank--but from the converter/other charging device. It is small, but when a system is teetering on the edge it may make the difference. In my case the demand is about 24 watts

2. Yes. Inverter/chargers such as the Magnum 3012 may draw up to 1800 watts. My first battery bank was 875 amp-hours and I pushed it HARD so it took more than just two hours to drop down to a lower demand.

3 & 4. the 12 volt needs can be met by the battery bank for many hours--once the Rv is cooled, charging should be restored.

A far GREATER concern is what the voltage drop will be using 2 A/c units on a 30 amp supply. I suspect that most pedestals will exhibit a lot of drop. An autoformer can help with the drop--but it may cause the pedestal breaker to cycle. I have had this happen with a single air conditioner, autoformer, and a weak 15 amp shore supply (unloaded voltage was 100).

The a/c did run for 30 minutes--which certainly helped make the RV more comfortable. I did not think to measure the temperature of the shore power breaker. When I reset the breaker, it ran it for a further 10 minutes, then tripped again.

dougrainer wrote:
1. The Inverter does NOT use any power when connected to Shore or Genset power
2. I suppose the comments about turning the Inverter OFF is directed at the CHARGER section of an Inverter/Charger. The ONLY hi Amp draw on the Charger section happens at initial 120 power up of an Inverter/Charger. THAT is what can be adjusted on an Inverter/Charger. But any adjustment is for the BULK charge at start up. Once 2 hours have passed, the hi amp draw on the charger is GONE and you have your float charge with draws minimal amps.
3. If you decide to turn the CHARGER section OFF, DUMB IDEA. That means you will drain your batteries. You NEED a constant charge to maintain the Coach batteries and run the 12 volt items in the RV
4. Turn a CONVERTER OFF?????? See item 3 above. SAME DUMB IDEA. Doug

Sorry, what I posted will fit 90% of Rv'ers. MOST Rv'ers are extremely ignorant of what and how their RV's are operated and run by the various appliances, that maintain operating the RV's. Just look at the thousands of posts just on these RV.net forums over the years with what I think are dumb questions. But, there are NO dumb questions, just people that have NO IDEA how their RV's operate in various conditions. I use the KISS(keep it simple stupid) method when dealing with my customers. Trying to go into various programming features will just cause problems for most RV'ers. Turn the Charger section OFF on an Inverter/charger? NOT SMART. You must then REMEMBER to turn it back on. At my Dealership, at least 90% of my customers drop off their Motorhomes with the INVERTER/CHARGER ON. When I bring the unit in a few days later, the coach batteries are DEAD, because the Inverter was out of sight and out of Mind. That is why I advise customers to NEVER turn the Inverter ON, unless they need Inverted Power. With Residentials now standard on almost all Diesels, the Inverter is now left on and forgotten about when storing(no 120 at storage lot) or dropping off for service. Doug

[pianotuna]

Hi doug,

1. If the inverter is on does draw a small amount of energy--not from the battery bank--but from the converter/other charging device. It is small, but when a system is teetering on the edge it may make the difference. In my case the demand is about 24 watts

2. Yes. Inverter/chargers such as the Magnum 3012 may draw up to 1800 watts. My first battery bank was 875 amp-hours and I pushed it HARD so it took more than just two hours to drop down to a lower demand.

3 & 4. the 12 volt needs can be met by the battery bank for many hours--once the Rv is cooled, charging should be restored.

A far GREATER concern is what the voltage drop will be using 2 A/c units on a 30 amp supply. I suspect that most pedestals will exhibit a lot of drop. An autoformer can help with the drop--but it may cause the pedestal breaker to cycle. I have had this happen with a single air conditioner, autoformer, and a weak 15 amp shore supply (unloaded voltage was 100).

The a/c did run for 30 minutes--which certainly helped make the RV more comfortable. I did not think to measure the temperature of the shore power breaker. When I reset the breaker, it ran it for a further 10 minutes, then tripped again.

dougrainer wrote:
1. The Inverter does NOT use any power when connected to Shore or Genset power
2. I suppose the comments about turning the Inverter OFF is directed at the CHARGER section of an Inverter/Charger. The ONLY hi Amp draw on the Charger section happens at initial 120 power up of an Inverter/Charger. THAT is what can be adjusted on an Inverter/Charger. But any adjustment is for the BULK charge at start up. Once 2 hours have passed, the hi amp draw on the charger is GONE and you have your float charge with draws minimal amps.
3. If you decide to turn the CHARGER section OFF, DUMB IDEA. That means you will drain your batteries. You NEED a constant charge to maintain the Coach batteries and run the 12 volt items in the RV
4. Turn a CONVERTER OFF?????? See item 3 above. SAME DUMB IDEA. Doug

[tropical36]

After all the above is said and done, I always split the rear ac circuit on a 30amp coach for running it on a separate pedestal circuit and as a matter of routine.
The same can be done with a 50amp coach, if using a 30amp service, has become a matter of routine or just for druthers, if you will.

[Executive45]

I'd go with the simple stuff. Run the generator. Gas is cheap compared to momma not being happy...just sayin.....Dennis

[dougrainer]

1. The Inverter does NOT use any power when connected to Shore or Genset power
2. I suppose the comments about turning the Inverter OFF is directed at the CHARGER section of an Inverter/Charger. The ONLY hi Amp draw on the Charger section happens at initial 120 power up of an Inverter/Charger. THAT is what can be adjusted on an Inverter/Charger. But any adjustment is for the BULK charge at start up. Once 2 hours have passed, the hi amp draw on the charger is GONE and you have your float charge with draws minimal amps.
3. If you decide to turn the CHARGER section OFF, DUMB IDEA. That means you will drain your batteries. You NEED a constant charge to maintain the Coach batteries and run the 12 volt items in the RV
4. Turn a CONVERTER OFF?????? See item 3 above. SAME DUMB IDEA. Doug

[Monkeyman_and_L]

With the power modifications via the breaker panel we were quite comfortable last night.

[Monkeyman_and_L]

That's an interesting idea. I think our fix will be to not rent 30 amp sites in the summer though. I can easily do what you described. Running the cord would be the biggest issue.

At this site it wouldn't make a difference, there's no Edison plug for ancillary equipment.

[wa8yxm]

I used to have two Carrier Air V 13,500 BTU units. add in the converter with fully charged batteries I drew 27 amps by measurement... That's all now that is more than a 30 amp breaker will carry for a long period.. At least most of 'em

Since then I've "Broken out" (technical term) one of the A/C's

What I did was disconnect the power feed from the breaker box and move it to a junction box

I ran a brand new TWELVE GAUGE wire line from the breaker box to a 15/20 amp outlet in an exterior compartment (protected from weather) And from the junction box I ran an 2nd 12 Ga line to a plug (20 amp 120 volt) in the same spot.. It is recommended you put a breaker (20 amp) in the 2nd line

Now on MOST (not all) 30 amp sites I can unplug. and using a 12ga extension cord (Big box home imporovement, Sears, K-Mart.. I like the sears/k-mart ones with the lock on outlet) and plug into the park's 20 amp socket.

Works.