Jump to content


Validated Members
  • Content Count

  • Joined

  • Last visited

About oldjohnt

  • Rank
    Major Contributor

Optional Fields

  • SKP#
  • Lifetime Member

Profile Information

  • Gender
  • Location
  • Interests
    RV Travel, Antique Tractor Shows, Bluegrass Festivals, Snowbirding

Recent Profile Visitors

6,209 profile views
  1. Glenn, good question but I have no idea what "they" are talking about. I'm rusty as an engineer being so long retired, but believe the laws of physics still apply. Any black box device which converts DC of X volts to DC of Y Volts IS NOT 100% EFFICIENT there are heat losses, same as for Inverters or Chargers etc. I don't understand "never charge battery while hooked up" If I recall you are going to use a 24 or 48 volt system but need a DC to DC Converter to power up 12 VDC appliances. If so that's all well n good but as you know its NOT 100% efficient. Perhaps ?? They mean when no load is applied to the devices output it doesn't draw any current from its input source ??? If so I like that !! John T Sorry I just don't understand what they are talking about
  2. Yeppers, you got it Kirk. Hey I'm not too far from you I'm in Kilgore now headed to SKP in Livingston later, its starting to warm up finally. After I have used Hengs Roof Coating I followed up with a bit of Dicor "Self Leveling Lap Sealant" around my roof top vents etc., never had a problem BUT I don't know much about any of this topic...……… Hopefully my Brake Buddy Loner will be there and I can return my air leaking unit to them for repairs before I go to Austin for Thanksgiving with my favorite daughter. Take care John T
  3. I'm NO expert in this area or either product mentioned so take this with a grain of salt. FWIW I would first apply the roof coating then follow up with Dicor where needed. For years I have used Hengs rubber roof coating and applied Dicor over top in critical areas like around vents etc AND NEVER HAD A PROBLEM. YES I would remove old dried up product and clean before applying new Dicor John T
  4. It appears Brake Buddy in Kansas may have great customer service and repair, only time will tell ???? I'm on the road towing my Honda CRV behind the motorhome and my Brake Buddy Classic develops an air leak causing the compressor to run too long too often. I'ma thinking/guessing the air pressure regulator is the problem (maybe something minor I can cure, I will look) and if I had plenty of time (ordering parts is time consuming) Id order parts and repair it myself, but I'm on the move and don't like to drive without the toads auxiliary brake. Soooooooo I call Brake Buddy Tech Support (answered immediate by an English speaking gent NOT Habib in Pakistan) and they inform me they can ship me a loner unit almost overnight,,,,,,,I return my unit in the same box,,,,,They diagnose the problem and cost of repair and call me for authorization,,,,,,,,,,If repaired they ship it out to me and I return the loner,,,,,,The price estimates (versus what may be wrong) they gave me were very reasonable and when returned its all serviced and updated and supposedly good as new ??? After researching my models problems and looking at the cost of new or used units and the time factors in repair or replace (myself or let Brake Buddy do it) and if an inspection doesn't show something minor like an obvious leak I can easily cure, I can order the loner and it will be waiting for me when I arrive at SKP in Livingston Texas. I am happy with the Brake Buddy type of toad braking and don't want to charge systems now, so I may take them up on their offer. Blue Ox and Roadmaster also make similar units (maybe better maybe not) but considering cost I'm sticking with Brake Buddy for now. Any others have similar experience with Brake Buddy Classic and their service ??? John T Live from Hot Springs where it was 18 last night brrrrrrrrrrrrrrrrrr Dry camping has been an experience when its this darn cold grrrrrrrrrrr
  5. Lance, thanks it comes from yearssssssss of technical and spec writing. At our huge Naval Industrial Base we did our own electrical engineering for years and later on had to write even more when we advertised a job for A & E firms to submit proposals, it was more fun when we did our own work in house …………...Farm it out to private industry became popular before I retired. Oh well such is "progress" ya reckon ?? John T
  6. Good thoughts jc, Likewise, I've not seen auxiliary disconnects/protection installed on an Inverters output (don't mean they don't exist) and so long as they have their own internal overcurrent protection such that the device AS WELL AS the output wiring is protected NONE IS REQUIRED. I have no idea what the OP has so I figured no harm educating him. Indeed, there needs to be protection on the input side to protect the inverter itself. And don't forget, the wiring FROM battery TO Inverters input needs protected which needs to be at the battery. Nice sparky chatting with you jc John T Live from Walmart in Union City TN headed to Jonesboro Arkansas
  7. Glenn, thanks for the updates, now that I better understand your question I can provide more guidance, here goes: 1) The main breakers in your AC distribution panels are well n good HOWEVER they only protect current and loads downstream and after them. They do NOT protect the wiring FROM the Inverter TO the panels. A short there would NOT cause the panels main breaker to trip, that fault current isn't flowing through the main breaker, get it ???? 2) Typically an energy source, be it a Genset or an Inverter, have their own built in overcurrent protection to protect the component. I have no idea what kind of overcurrent protection or disconnect methods your Inverter currently has. I would suspect more along the lines of overcurrent protection versus any pure On/Off disconnect. 3) You DO need to protect the conductors FROM the Inverter TO the panels which may ?? be covered by the built in overcurrent protection device currently installed PROVIDED THAT its sized to protect the wire (Inverter to Panel) NOT sized only to protect the device. IE as an example (even if not realistic) if the equipment was protected at 100 amps but you had less then 100 amp rated wire (Inverter to panel) THE WIRE ITSELF ISNT ADEQUATELY PROTECTED. It wouldn't be good engineering to use wire having less ampacity then the Inverter can produce and, hopefully, the Inverter already has all the protection required. 4) Regardless, it wouldn't hurt to install fused disconnects or breakers that could serve as a disconnect method PLUS provide secondary overcurrent protection for the Inverter if you so choose. A "Fused" Disconnect serves a dual purpose versus a disconnect only. BOTTOM LINE you DO need to protect the wiring FROM Inverter TO Panel as the panels main circuit breaker ONLY protects what's downstream and after. If the Inverter has adequate built in overcurrent protection that can protect the Inverter and the wiring to the panel (See Para 3) fine. If in doubt, given the size of your system, if not already protected a breaker of fused disconnect might be a good safety tool. NOTE your Inverter may already have all the overcurrent protection and disconnect method built in, I just cant say from here. Nuff said for now John T
  8. Thanks Ray, yep we got outa Dodge heading South lol John T
  9. Good questions, charging a toad via the tow vehicles alternator is a good scheme, I've done it successfully for years. 1) The current draw would be (even if nothing else) LIMITED by the fuse or breaker feeding the toad charging circuit 2) The current draw is further LIMITED by whatever capacity the circuit/source providing the charging is capable of providing. 3) The current draw can be limited due to the current rating and resistance (line voltage drop) of the Tow vehicle to Toad plug/connector PLUS is subject to the Voltage Regulation scheme on the tow vehicles charging system. 4) The amount of charging current the toads battery might attempt to draw is a function of: The toad battery voltage and state of charge,,,,,,,,,,,The resistance and resultant line voltage drop in the circuit FROM tow vehicles charging circuit TO the toads battery. 5) To provide charging current FROM tow vehicles charging system TO the toad battery one should reduce line voltage drop (bigger wire and/or short distance as possible) and tap off a circuit or location that has the capacity to deliver as much charging current as possible yet NOT overtax source capacity . THAT BEING SAID A "tail light circuit" would be a poor choice due to its limited amount of current capacity (wire size and fuse/breaker) it lacks capacity to supply much current to the toad in the first place and if were exceeded the fuse would blow. A "better" method would be connecting to the tow vehicles battery with a fuse and run a circuit and connectors with sufficient ampacity back to the toad battery via another fuse located there. Other methods might involve the use of sold state or mechanical relay battery isolators for connection or disconnection of the tow vehicle and the toad batteries To prevent backfeed from toad to tow vehicle some install an in line Diode which works but does have a 0.6 voltage drop across it Others install a relay in the charge circuit such that the remote charging circuit is closed when the tow vehicle is running but opens otherwise. One fairly common even if NOT ideal or best or perfect is to attach say a 10 or 8 or even larger wire and fuse at the tow vehicle battery, run it back to an auxiliary terminal on an RV 7 pole round connector, and run a wire from the toad battery and a fuse to the cord and plug. Such could contain a diode as discussed above or a relay to prevent the toad battery backfeeding the tow vehicle. I have seen others use heavy wire from tow vehicles battery, a high current rated toad to two vehicle connector, and perhaps a relay or other isolation or back feed prevention device. Some don't use any diode or relay or isolation scheme but instead rely on simply disconnecting the toad when not in tow. BOTTOM LINE to maximize the charging current to a toad you need a high current capacity source, adequate overcurrent protection at BOTH toad and tow vehicle, high ampacity wiring to limit voltage drop in the charge circuit, back feed prevention and isolation methods so toad can receive charging current yet not reverse discharge tow vehicle, sufficient ampacity connection methods from toad to tow vehicle. I would consider at the very minimum 8 or 10 gauge fuse protected wire from tow vehicle battery back to an aux terminal on a 7 pole round connector with a wire up to toads battery using a diode or relay isolation method to prevent backfeed or else just unplug when not under tow. Better if bigger wire and adequate connection methods with idiot proof isolation and back feed protection. NOTE The source voltage and regulation scheme, the Voltage and SOC of the toad battery along with the resistance and voltage drop of any wiring plays a HUGE role in just how many actual charging amps may or may not get delivered to the toad NOTE Despite big enough wire and sufficient rated plugs and cords and connectors and a good source these methods aren't perfect but as long as they keep the toad battery sufficient charged GO FOR IT. There are a ton of 12 or 10 gauge charge wires using the RV 7 pole round RV connector ran from tow vehicle to toads battery with or without diodes or relays out there that get a person by. NOTE one might also purposely limit the max charging current the toad battery can receive and/or provide max current protection so as to NOT over tax the tow vehicles alternator !!!!!!!!!!!!! NOTE The above methods, especially if smaller wire and using the RV 7 pole round connector, I consider a maintenance to a trickle charge NOT any high current heavy duty full battery charge. John T Coming to you live in the RV currently dry camped near Holland Indiana cold brrrrrrrrrrrrrrrrrr furnace and LP supply is getting a workout
  10. Glenn, (you're obviously already aware of the hazards of incorrectly tying multiple 120 VAC sources) sure, if you like you could install an AC disconnect on an Inverters output controlled however you like if safe and correct, but typically that's all handled by Transfer Switches. If plugged to shore power or a genset is running providing 120 VAC the Inverter isn't typically necessary so would be switched out of the circuit and the ONLY time you need to use your battery and Inverter to provide 120 VAC is when there's no shore or genset power available. While a person could install a disconnect on the Inverters 120 VAC output, there are plenty of alternative designs whereby such may or may not still be required. I have seen rigs where the dude plugs his RV power cord direct into an Inverter,,,,,,,,,,Where critical circuits are served by a Sub Panel fed by an Inverter,,,,,,,,,,,Where manual or automatic transfer switches select between shore or inverter or genset 120 VAC delivery. What IS REQUIRED is there be only one Neutral Ground Bond and Inverters can use relays to insure that. One method I see and like is the Combination Hybrid pass through Inverter Chargers that have their own built in transfer switches. There are all sorts of methods for connecting Inverters, Gensets, Chargers, Shore Power and safe selective switching and transfer and if an AC disconnect on an Inverters output remains necessary it's an easy install. NOTE an Overcurrent Protection device could be installed on an Inverters 120 VAC output to provide overcurrent protection PLUS used as a disconnect method if necessary or desired John T
  11. Obviously this is a matter of personal preference based on ones equipment (Batteries, Solar, Charging) and requirements as EITHER fridge works. Each has advantages as well as disadvantages WELL DUH. There's NO Right or Wrong answer to this one, what's best for one rig may be the opposite for another persons rig...……... I have used BOTH and actually I'm dry camped in my RV right now which has one of each (Residential + Absorption) If you EITHER have adequate battery and re charging capacity (Solar or Genset etc) Orrrrrrrrrr Without battery and recharging ability you can turn off a residential fridge for x amount of time before you're plugged to shore power again, a residential can serve you just fine HOWEVER if you have limited battery or re charging capacity (solar or genset) and do a lot of dry camping an Absorption is a good choice. Of course each will use what best suits their equipment and lifestyle. Gotta love choices and options John T
  12. Noooooooooooooooooo Way lol I've just been retired too darn long and rusty as an old nail (not current on latest codes either) on a lot of this but have fun and try to help best I can. I've been off the road a while but headed South soon. Take care n have a great day John T
  13. When you posted that at least it got their "attention" even if they did nothing LOL Sounds like something I'd do myself. Congratulations on your repair John T
  14. rb, as I best recall (NO Warranty) the so called "skin effect" was only of major concern when talking high frequency and NOT in DC circuits. You're only talking about a 25 ft DC run OUTSIDE an RV FROM a portable energy source TO an external Outlet/Plug (or other connection method) at (if 17 Vmp at 120 watts) 7 Amps DC max, so I think 40 Amp rated wire (such as #8 Copper or other 40 Amp rated equivalent) be it some sort of so called "Marine Grade", be it some sort of so called "Solar Rated" or be it some sort of so called "Welding Cable" will "WORK" satisfactory. NOTE, I'm NOT saying the grades or ratings or any UL or NEC or RVIA approved wire (to the extent any such exist or are even applicable) shouldn't be considered and its best to reduce line voltage drop as much as one can, I'm ONLY saying ANY of such conductors approved for exterior and wet locations with ultraviolet protection and 40 Amp rated is a decent choice and I wouldn't loose much sleep overthinking or worrying too much beyond that. CONGRATULATIONS you ask good questions and are doing research so you should end up with a good product. John T
  15. FWIW Over many years I have experienced the same satisfaction as Glenn above when it comes to "welding cable". While a past used equipment dealer and farmer I came across a ton of welding cable and it generally speaking had good quality tough high abrasive resistant jacket/insulation as it got dragged down gravel or blacktop driveways up over and around all sorts of sharp steel or machinery and sharp bends plus often sat outside on a welding truck exposed to sun rain wind snow n drastic temperature changes grrrrrrrrrrrrrr it better be tough and good quality to withstand all that lol Of course, there are different grades and brands and quality, some maybe poor some maybe excellent, some cheap some expensive, but I may have lucked out as that which I came across happen to be great quality and endurability while some others may have observed poor quality...….That comes as no surprise to me as there are a ton of manufacturers and grades out there. Unfortunately absent deep research I don't know how to tell what types or brands or specs or codes or ratings are good or bad for any specific application, so I wouldn't make any recommendations in the dark. DO YOUR HOMEWORK As far as any "Solar" wiring rating (UL or NEC or RVIA etc) a panel is a DC energy source such as a battery or charger etc etc so if a person were choosing so called "Marine Grade" or some sort of so called "Solar Grade" one thing I see as critical is the environment so if the wire is ran on an RV rooftop exposed to sun, rain and temp changes and regardless if the energy source were a charger or solar panel you need good ultraviolet protection as well as other element protection including flexibility and vibration resistance. Marine Grade, Solar Rated, Welding Cable, UL, NEC, RVIA, may all have a role in decision making. Do your research and make your choice that's best for YOU...………. Best wishes yall, very fun and interesting thread for us sparkies at least lol John T
  • Create New...