Power Center Upgrades and Adding Batteries

Discussion in 'Wiring' started by Balthisar, Nov 5, 2018.

  1. Balthisar

    Balthisar Active Member

    Messages:
    306
    Likes Received:
    158
    Joined:
    Jun 26, 2018
    Location:
    Plymouth, MI USA
    So, I’m going to add some batteries to my 1991 Palomino TXL, which has never had them. I’m also going to re-wire and add a new power center while gutting the interior. This question is about “modern” power centers.

    My current, presumably original, power center has a rocker switch to switch between battery power and converter power, but the converters that I’m looking at online (such as this one) don’t seem to have one.

    Does this mean that the battery is always part of the circuit? That is, if I have shore power, the battery is being tended/charged, and if I don’t have shore power, then I’d be pulling my 12VDC from the batteries?

    If the previous is correct, then why the heck does my current converter have a battery rocker switch? Is it likely that my current converter is not a charger (given that the pup has never had a battery or location for one), and so this otherwise useless switch would be needed? I mention that this is a simple rocker switch, and not a heavy weight, physical battery disconnect switch.

    Thanks!
     
  2. rabird

    rabird Howdy!

    Messages:
    6,706
    Likes Received:
    303
    Joined:
    Mar 3, 2006
    Location:
    TX
    Raycfe likes this.
  3. Balthisar

    Balthisar Active Member

    Messages:
    306
    Likes Received:
    158
    Joined:
    Jun 26, 2018
    Location:
    Plymouth, MI USA
    Great, thanks! I think while I'm at it, I'm going to go 50A, so that I can run the A/C or heat strip at the same time as I can boil water. At least, while on AC. Most sites are 30A so I won't be able to do this most of the time, but if I happen into 50A, at least I know I'll be able to.
     
  4. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

    Messages:
    3,161
    Likes Received:
    299
    Joined:
    Jul 18, 2013
    Location:
    Thornville, OH
    That is a lot of converter for a popup. I think you had better read the specs for the 8550. I think the max input from shore power is 120V at 30 amps for that unit??

    We have a WF-8555. The max input power for it is 120V AC - 30 AMP. The max 12V power is 55 amps. Never came cloes to using the 55 amps output. Never had an issue with the 30 amp 120V input, except once: It was when we first pulled into a CS and need to recharge the 2 batteries and it was 30 outside. We started up heat strip 1500 watts in the AC, a stand alone 1500 watt electric heater, started heating up our water heater with the 1200 watt electric optional heating element, and running the electric fridge. It trip the 30 amp breaker. I turned the water heater and fridge to propane and all was good. But I have never come even close to the 55 amp of the DC output of the converter. A WF-30, with 30 amps 12V output would be just fine for me.

    I was not thinking about it, because I normally am only running one electric heater. When I calculated the number of watts and converted to amps. I realized in the future I will bring a 12 gauge extension cord for the second heater if I think I need two heater. I will run the cord to the power post 20 amp outlet. Giving me 50 amps.
     
  5. rabird

    rabird Howdy!

    Messages:
    6,706
    Likes Received:
    303
    Joined:
    Mar 3, 2006
    Location:
    TX
    converter side, they are normally rated in DC amps
    RVs with 50A service usually have a stand alone converter of 45-80+ amp DC.

    50A service is 2 hot legs of 50A each capable of 240v@50A, most big RVs use it as 2 x 120v@50, way too much for a PU.
     
  6. Balthisar

    Balthisar Active Member

    Messages:
    306
    Likes Received:
    158
    Joined:
    Jun 26, 2018
    Location:
    Plymouth, MI USA
    Oh, the 8550 was just an example link. I'd size it properly.

    I'm not actually looking for high amp DC; all I have are incandescent bulbs, the pump, the blower motor. However, when connected to shore power, I have an A/C that I don't use much, but it has a 1500W strip heater that I do use much. It saves a lot of propane. And I have a hybrid heat that's IIRC another 400W. And the electric kettle is 1800W. If all of these loads happen to be running at the same time, then I exceed a 30 amp circuit. With 30 amp service, it means powering things off to use the kettle.

    Because I'm replacing the power system anyway, the difference to go with 50 amp service vs 30 amp service is negligible. I'm not even looking to use both legs, because I'd be missing one of them when plugged back into 30 amp service (where I'd continue to juggle the loads as I do now).

    I've not thought out all of these details yet, but as long as we're talking about it, if the buss bars are the right size, I could use a 30 amp power center (which is only AC distribution anyway) with a 50 amp main breaker. When plugged into 30 amps, though, I'd be tripping the post instead of my own breaker (if I don't juggle the loads). I don't really like this idea; you should trip as close to the load as possible.

    I'm assuming the only difference for a 50 amp power center (physically) is the second buss bar for the second leg, and two main breakers. This would let me balance the loads between the legs. Since I don't have any 220 VAC appliances to worry about, I could even feed the same leg to both buss bars when I only have 30 amp service (juggling my loads, of course). This would depend on how those 30 amp to 50 amp plug adapters, work. I assume they split the same leg to both hots?

    Mostly this is just about giving me flexibility. Most of the time I only have 30 amp service, but if I happen to have 50 amps available, I'd like to be able to take advantage of it. And of course, the purpose for finally adding batteries is for (a) power failure mitigation like I had in October at Tahquanemon, and (b) so I can convince my wife to boondock (I will replace the DC bulbs with LED, and use a gas kettle, etc.).

    But you're right, I will never, ever take advantage of the full energy capacity of 50 amp service.
     
  7. MNTCamper

    MNTCamper Active Member

    Messages:
    886
    Likes Received:
    189
    Joined:
    Jun 14, 2014
    Location:
    MN
    I think you might be better off with a 30A converter. You are going to find that most sites that are for pop ups only have 30A service anyway and the 50A plug is completely different. 30A is a whole lot of power, about 3600 watts which is a huge draw for a pop up. There are a lot of 50A sites out there, but they are really geared toward larger RVs.
     
  8. jmkay1

    jmkay1 2004 Fleetwood/Coleman Utah

    Messages:
    4,836
    Likes Received:
    1,706
    Joined:
    Oct 10, 2013
    Location:
    Northern Virginia
    It's very rare for me to find a campsite with 50 amp where I stay. I have 30 amp and the normal household plug. When I camp with big power draw items I just bring an extension cord fish it through the canvas on the bunk end to the power post and plug it into the house hold plug. That way I can operate everything I need without having to disconnect anything. Some devises are on the extension cord and the rest on my inside electric. Even better, I can move the cord to where I want a plug vrs having to make due. At least on my camper there is no plug by the table or counter and by using the separate extension cord can have the plug where I need it.
     
  9. Sneezer

    Sneezer Well-Known Member

    Messages:
    1,527
    Likes Received:
    532
    Joined:
    Aug 8, 2015
    Location:
    DFW, TX
    I think you will be fine with a 30amp unit. I am a heavy power user. A/C, lights, multiple fans, TV and PlayStation plus a number of chargers for various phones. The only time I popped a breaker was when the convection oven was running.

    This past summer I ran a 2nd A/C with a dedicated heavy duty line to the power pole and was fine.

    Here in TX the 50amp spots are more expensive and geared to the big 5th wheels and motorhomes, and often have sewer and little shade. I find them less desirable than the 30amp spots.
     
  10. Balthisar

    Balthisar Active Member

    Messages:
    306
    Likes Received:
    158
    Joined:
    Jun 26, 2018
    Location:
    Plymouth, MI USA
    I'm actually not usually a heavy energy user. I'm really only thinking of peak loads, which should be infrequent enough. Kettle + Heat Strip + Hot Water gets me to over 3600 watts, plus converter inefficiency, lights, charging, etc. And I do have propane backups for all of this, so I'm not planning based on any specific need (but rather, "wants," such as I want to avoid filling the danged tanks all the time).

    My use of 50 amp spots is also fairly infrequent. They cost more here, too, but some of the state parks tend to be high-density unless you reserve a 50 amp spot.

    I think I will stay at 30 amps, but I'm going to do the load calculations to see if I can get away with 50 amps (single leg) when plugged into a 50 amp post. This should mainly be determined by my power cable gauge and new power center buss bar size.
     
  11. Raycfe

    Raycfe Waterford Ct.

    Messages:
    15,235
    Likes Received:
    1,449
    Joined:
    Oct 3, 2007
    Location:
    Waterford, Ct
    Do what you want, but sounds like overkill..... just my 2 cents
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.