jjrbus Posted October 26, 2015 Share Posted October 26, 2015 I am making headway on my electric and need input on my 12V. I have done a drawing and hoping for some suggestions on it. Jim Left click to enlarge Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 26, 2015 Share Posted October 26, 2015 It can go to your converter/charger +12 V the isolator will keep it from back feeding or your fuse block but the lugs are a good bit bigger on the converter/charger. You should have an inline fuse/breaker at the isolator end under the hood and one at the charger end all so. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 26, 2015 Author Share Posted October 26, 2015 I have looked at 100 schematics and not one shows the 12V vehicle input to the system, seems odd for a panel and converter/charger designed for an RV! Many show the converter + side to the VCC block on the 12V panel. It seems like the 12V from the vehicle would go to the 12V + lug on the fuse panel? I'm not getting it. Fuse on both ends makes sense. Thanks Jim Quote Link to comment Share on other sites More sharing options...
zero Posted October 26, 2015 Share Posted October 26, 2015 I don't understand what it is you are not seeing in the diagram. It clearly shows the connection. Positive from the battery is hooked in "daisy chain" fashion to the 12 volt fuse block and then on to the converter positive lug. Calls for 8 gauge copper wire no longer then a foot and a half. Note if you use 8 gauge - it has to be type THWN-2, THHN, XHHW-2, or USE-2. Otherwise you need 6 gauge copper wire. Only certain types of 8 gauge copper have the 55 amp "ampacity" needed. Any 6 gauge copper will have it. 6 gauge wire can also be run to 6 feet long if need with only a 2.8% drop. But - I'm not sure what you are calling an "input." The converter itself only does "output" in DC when it comes to any real current. Quote Link to comment Share on other sites More sharing options...
WME Posted October 26, 2015 Share Posted October 26, 2015 I ran a 4 ga. wire from the isolator to the house battery. I used a 40 amp CB at each end. Quote Link to comment Share on other sites More sharing options...
zero Posted October 26, 2015 Share Posted October 26, 2015 It's a matter of length. My 1978 Chinook has the "house battery" under the hood and is 15 feet from the 55 amp converter. Needs #2 copper wire. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 26, 2015 Author Share Posted October 26, 2015 If I knew what I was doing I am sure it would all be very clear. I can likely muddle my way through this...with a lot of help. Let me start here. The wire (looks factory) from the isolator under the hood to the panel is a # 8 Type MTW AWM 105°C the ampacity table rates MTW at 40 amp at 80° C, 50 amp at 75° C and 55 amp at 90° C. Mine is marked 105° C. In most things I would assume that the 105° C rating makes it a higher rated wire and is sufficient for my needs. But I do not know enough about wire to make that assumption. The run from isolator to panel is at most 15 Feet. The schematics I have found online do not spec wire size. OK different lengths of a run would require different sizes, that makes sense. One that I do find, specs #8 wire for The positive side and the ground wire. The electric I have done the ground was always allowed to be one size smaller, I have done a couple web searches and do not find an answer. My + wire from the panel to the house battery is a #6 and the neg wire is a #8. I might save some time by just buying new large wire? Thanks Jim Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 26, 2015 Share Posted October 26, 2015 The older converters could not be wired that way but the new switching supplies can if you feel that a larger wire will carry more current you are right but it would mean upgrading all of the wiring inline, isolator wiring etc. if you increase the wire size the smaller original wire cannot provide the current even if it is a short run. The bottom line is how much current you think you need to recharge the batteries? 35 amps, 50 amps? I can tell you your converter/charger will do a far better job than the truck will for multiple reasons. Pretty much all of the Toy Homes are wired with a #8 wire from the isolator it can give you 35 amps on a good day. So how much charging do you need to recharge your batteries? People have a tendency to stress over batteries going dead during a camping trip and of course they can if the demand is higher than the supply so what are your needs? Microwave, big screen TV etc.? I can go 5 days or more without any kind of recharge in the summer months so it’s all about what you really need to be comfortable. You can use a smaller negative wire than the positive that does not need to be replaced. The temp rating is insolation the wire heats with load and it's current is degraded when it is packed in with other wires and heats up. Quote Link to comment Share on other sites More sharing options...
zero Posted October 27, 2015 Share Posted October 27, 2015 The wire (looks factory) from the isolator under the hood to the panel is a # 8 Type MTW AWM The run from isolator to panel is at most 15 Feet. The electric I have done the ground was always allowed to be one size smaller, Thanks Jim MTW/AWM wire has the same ampacity as THHN-2 wire so it's OK for a 55 amp rating as far as safety goes. It is, however, WAY too small for a 15 foot run. For that you need at least #2 gauge copper wire. At 55 amps with a 15 foot run, #2 has a 2.8% drop/loss. That is OK. #8 would be over 11% loss and NOT suitable. In regard to ground allowed to be one size smaller? NEVER when it is used as part of a circuit. You are thinking of grounds when used as a normally non-current carrying safety like in household wiring. It is NOT a ground when used for DC wiring in your RV. Technically there is NO ground with an RV. Just a steel chassis that is used as one large common "wire." Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 27, 2015 Author Share Posted October 27, 2015 Ah ha! It;s not a ground it is 1/2 of the circuit. I do not have an issue with slow charging of the house battery due to the voltage drop with the #8 wire from the isolator to the panel. Unless it is a safety issue? If it did become troublesome I could change it later. My travel plans would have the battery's charged before I drove anyplace and rarely using the alternator to charge them. So I would change the present 40 amp breaker at the isolator to a 55 amp. But is the islolator going to be rated at 55 amps? Something else I have to look up. Which brings up a question, my PD 9145A converter/charger is rated at 13.6 V at 45 amp output. Do I really need 55 amp breakers? I think I now understand the VCC lug on the 12 fuse block, it appears to be a fused lug to protect the converter charger from reverse polarity. I could not wrap my head around why they were separating the converter charger output from the Pos lug on the fuse-block, made no sense. Thanks for all the input, greatly appreciated. Jim Quote Link to comment Share on other sites More sharing options...
zero Posted October 27, 2015 Share Posted October 27, 2015 As long as the wire is rated for the ampacity involved - there is no safety issue regardless if it's 10 inches long or 100 feet long. The point is - the fuse blows or breaker trips before the wire can melt. The length versus wire-size and amps is important to keep voltage where you need it. Not about "charging speed." Let's say your charger is designed to send 13.8 volts to charge your battery. If you have wire so small that there is a 10% voltage drop - that means the charger sends out 13.8 volts - but by the time it gets to the battery - it is only 12.4 volts and that will not charge a 12 volt battery at all. A 12 volt battery is around 12.7 volts and voltage needs to be higher then that to charge it. I'm just giving hypotheticals here to make a point. I don't know the specific needs of your converter charger. I do know that 55 amps sent though 15 feet of # 8 wire results in an 11% voltage drop. 55 amps is the max output and does not mean it's often used to that extent. If the same converter is only putting out 30 amps - the drop in 15 feet of # 8 wire is only 6%. Still too much as far as I'm concerned. Wiring is usually done to keep loss no higher then 2.5%. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 27, 2015 Author Share Posted October 27, 2015 Not trying to challenge what you are saying, but am confused. The Toy was delivered with about 15 feet of #8 wire from the isolator to the electrical panel protected with a 40 amp breaker on each end, then there is another 8 feet of #8 wire from the isolator to the truck battery, a total of 23 feet. From the panel to the house battery is another max 10 feet of # 6 wire. We are talking about charging the house battery with the alternator through about 33 feet of wire. According to the load calculator would require a #1 AWG for the entire 33 feet to reach a loss of 2.5%. With the current setup the voltage loss is over 10% Which seems like it is useless? The PD9145 Converter charger putting out max 45 amps at boost mode of 14.4 volts through about 10 feet of # 6 wire would have a voltage drop of 2.50% , and at normal mode of 13.6V would have a drop of 2.65% according to the calculator. That is from the converter charger to the house battery. The distribution panel is in the usual place in my 94 Sea Breeze at the far end of the couch and the house battery is on the opposite side of the toy. Sure seems like the house battery is in the wrong place! Jim Quote Link to comment Share on other sites More sharing options...
zero Posted October 27, 2015 Share Posted October 27, 2015 33 feet with #8 to carry 40 amps is just plain no good. Let's say the alternator tries to send out 40 amps of charge current @ 14.2 volts (that's normal). If it had to travel through 33 feet of # 8 copper wire - the voltage would be 14.2 at the alternator end, and 12.1 volts IF it came out the other end. It would NOT however since 12.1 is less voltage then a twelve-volt battery that is 12.7 volts approx. That being said -I don't understand the wiring you are describing. Situation #1 (like in a Toyota Chinook). "House" battery is up front under the hood. There is #6 wire from the alternator to the isolator with about a 4' run. Then from the isolator to the "house" battery is at most - another 3'. So, 7 feet in all. From the "house" battery in front - to the back - is around 14 feet of #8 wire to power the RV area. At 30 amps there is a 5.7% drop. So the 12.7 volts from the "house" battery in front drops to 12 volts when it makes it out back. Not great - but acceptable. Situation #2 (like my Minicruiser came with). "House" battery is in back on the opposite side of the converter. Starting up front under the hood - there is about 4' of #6 wire from the 55 amp alternator to the isolator. From the isolator - to the "house" battery in back - is about 16 feet of # 8 wire on a 30 amp breaker. That results in a 5.4% drop when charging at 30 amps @ 14.2 volts, and a 2.6% drop when charging at 15 amps. So even at 30 amps - voltage is 13.4 volts and still charges the "house" battery. Not ideal but it works. I rewired my Minicruiser (situation #2) because I wanted two "house" batteries and also more charge current from the alternator. I also got rid of the rectifier-type isolator because that also causes loss. I installed a relay in it's place. So now - I've got # 2 copper running from the relay under the hood - to the back. So 16 feet of # 2 with a 60 amp auto-reset breaker on each end. Even if the alternator charged at it's full 60 amps - voltage drop is only 2.8%. So it's 14.2 volts at the alternator - and 13.8 volts when it makes it to the house batteries. The reason why I did that is not to get 60 amps of battery charge. It's to help run my microwave. When I run my microwave at full heat - I start the Toyota engine and that charge current helps the two batteries to keep voltage high enough to run the inverter - to run the microwave. Inverters and microwaves at a separate story. In normal car and truck wiring - most of the so-called "12 volt" electrical system is designed to work well at 9.6 volts. So the cranking battery and the heavy cables are designed to deliver 9.6 volts and NOT 12 volts. But when you wire in an inverter - it must always have above 10.5-11 volts or it will automatically shut off. That is very hard to do with a big load and even two house batteries. When a microwave first starts - that momentary surge will be around 160 amps on the DC input. At 160 amps many deep-cycle batteries - even a pair of them -will drop to 10.5 volts for just a fraction of a second. That's all it takes to shut the inverter down. Thus the extra charge wire I put in. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 27, 2015 Share Posted October 27, 2015 The ground is a name it is used as a return so you can call it anything you want they are synonymous. Look at the truck frame as a very big wire that will carry thousands of amps. In house hold wiring the neutral and the ground are one in the same so it can easily be called either there are only two wires on a residential power pole and the lower one is connected to ground in many places. The ground spike at the house is for protection in case of an overhead failure such as a rising potential due to a poor connection they are both connected together. As far as useless the #8 has been used for charging for a long time in all sorts of RV applications and in most circumstances it will work fine start adding extra batteries and heavy loads is where the problems occur and again just replacing the one wire will not correct the problem it goes all the way back to the alternator. A decent charge voltage is 13.2 to 13.8 so check it at the coach battery and see what you get. The charger/converter is a far better charger the alternator is doing other things along with dealing with the coach battery so it's output to the coach is limited. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 27, 2015 Share Posted October 27, 2015 Ah ha! It;s not a ground it is 1/2 of the circuit. I do not have an issue with slow charging of the house battery due to the voltage drop with the #8 wire from the isolator to the panel. Unless it is a safety issue? If it did become troublesome I could change it later. My travel plans would have the battery's charged before I drove anyplace and rarely using the alternator to charge them. So I would change the present 40 amp breaker at the isolator to a 55 amp. But is the islolator going to be rated at 55 amps? Something else I have to look up. Which brings up a question, my PD 9145A converter/charger is rated at 13.6 V at 45 amp output. Do I really need 55 amp breakers? I think I now understand the VCC lug on the 12 fuse block, it appears to be a fused lug to protect the converter charger from reverse polarity. I could not wrap my head around why they were separating the converter charger output from the Pos lug on the fuse-block, made no sense. Thanks for all the input, greatly appreciated. Jim As soon as you plug the camper in it is indeed the true definition of a ground as all of the connections both 120 volt and 12 volt are now "grounded" to the earth via the power post. Yes you need 55 amp trips for surge current. There are two fuses in your converter/charger to protect it from reverse polarity and overload all ready. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 27, 2015 Author Share Posted October 27, 2015 33 feet with #8 to carry 40 amps is just plain no good. Let's say the alternator tries to send out 40 amps of charge current @ 14.2 volts (that's normal). If it had to travel through 33 feet of # 8 copper wire - the voltage would be 14.2 at the alternator end, and 12.1 volts IF it came out the other end. It would NOT however since 12.1 is less voltage then a twelve-volt battery that is 12.7 volts approx. That being said -I don't understand the wiring you are describing. I should have went to bed instead of typing a response! I was describing what I believe is the wiring that National did from the truck battery in front to the converter/charger. distribution panel to the house battery. The truck battery is on the passenger side, the isolator is on the driver side and the distribution panel is on the driver side, the house battery is on the passenger side behind the wheel well. Very inefficient design, looks like anyone with this OE setup is not charging their battery when driving? If running a larger wire I would run it straight back from the truck battery along the frame to the house battery, it would be about 1/3 shorter! Relocating house battery might work also, but does not seem practical. Situation #1 (like in a Toyota Chinook). "House" battery is up front under the hood. There is #6 wire from the alternator to the isolator with about a 4' run. Then from the isolator to the "house" battery is at most - another 3'. So, 7 feet in all. From the "house" battery in front - to the back - is around 14 feet of #8 wire to power the RV area. At 30 amps there is a 5.7% drop. So the 12.7 volts from the "house" battery in front drops to 12 volts when it makes it out back. Not great - but acceptable. Much better than my 33 feet. Situation #2 (like my Minicruiser came with). "House" battery is in back on the opposite side of the converter. Starting up front under the hood - there is about 4' of #6 wire from the 55 amp alternator to the isolator. From the isolator - to the "house" battery in back - is about 16 feet of # 8 wire on a 30 amp breaker. That results in a 5.4% drop when charging at 30 amps @ 14.2 volts, and a 2.6% drop when charging at 15 amps. So even at 30 amps - voltage is 13.4 volts and still charges the "house" battery. Not ideal but it works. I rewired my Minicruiser (situation #2) because I wanted two "house" batteries and also more charge current from the alternator. I also got rid of the rectifier-type isolator because that also causes loss. I installed a relay in it's place. So now - I've got # 2 copper running from the relay under the hood - to the back. So 16 feet of # 2 with a 60 amp auto-reset breaker on each end. Even if the alternator charged at it's full 60 amps - voltage drop is only 2.8%. So it's 14.2 volts at the alternator - and 13.8 volts when it makes it to the house batteries. The reason why I did that is not to get 60 amps of battery charge. It's to help run my microwave. When I run my microwave at full heat - I start the Toyota engine and that charge current helps the two batteries to keep voltage high enough to run the inverter - to run the microwave. Inverters and microwaves at a separate story. In normal car and truck wiring - most of the so-called "12 volt" electrical system is designed to work well at 9.6 volts. So the cranking battery and the heavy cables are designed to deliver 9.6 volts and NOT 12 volts. But when you wire in an inverter - it must always have above 10.5-11 volts or it will automatically shut off. That is very hard to do with a big load and even two house batteries. When a microwave first starts - that momentary surge will be around 160 amps on the DC input. At 160 amps many deep-cycle batteries - even a pair of them -will drop to 10.5 volts for just a fraction of a second. That's all it takes to shut the inverter down. Thus the extra charge wire I put in. Thanks for the response and information, always appreciated. I will mull all this over as I think up new questions. Jim SW FL Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 27, 2015 Author Share Posted October 27, 2015 As soon as you plug the camper in it is indeed the true definition of a ground as all of the connections both 120 volt and 12 volt are now "grounded" to the earth via the power post. Yes you need 55 amp trips for surge current. There are two fuses in your converter/charger to protect it from reverse polarity and overload all ready. Surge current, thanks for that one. I have been putting off ordering breakers until I was sure. Jim Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 27, 2015 Author Share Posted October 27, 2015 The ground is a name it is used as a return so you can call it anything you want they are synonymous. Look at the truck frame as a very big wire that will carry thousands of amps. In house hold wiring the neutral and the ground are one in the same so it can easily be called either there are only two wires on a residential power pole and the lower one is connected to ground in many places. The ground spike at the house is for protection in case of an overhead failure such as a rising potential due to a poor connection they are both connected together. As far as useless the #8 has been used for charging for a long time in all sorts of RV applications and in most circumstances it will work fine start adding extra batteries and heavy loads is where the problems occur and again just replacing the one wire will not correct the problem it goes all the way back to the alternator. A decent charge voltage is 13.2 to 13.8 so check it at the coach battery and see what you get. The charger/converter is a far better charger the alternator is doing other things along with dealing with the coach battery so it's output to the coach is limited. According to the tables and charts, my current system cannot work. It would be interesting to test it, but I have everything torn apart and would take too much effort to jury rig it for a test. If I ever get done I will check the voltages to see what it really is. Thanks for the input and info greatly appreciated. Jim SW FL Quote Link to comment Share on other sites More sharing options...
zero Posted October 27, 2015 Share Posted October 27, 2015 According to the tables and charts, my current system cannot work. It would be interesting to test it, but I have everything torn apart and would take too much effort to jury rig it for a test. If I ever get done I will check the voltages to see what it really is. Thanks for the input and info greatly appreciated. Jim SW FL It usually does not add much expense to use big enough wire to handle max current. I cannot think of a good reason not to. What MaineAH stated . . . "In house hold wiring the neutral and the ground are one in the same so it can easily be called either there are only two wires on a residential power pole and the lower one is connected to ground in many places" is not really true. I'm not trying to nick-pick but since you've been asking questions - might as well get it right. Ground and neutral are NOT the same in household wiring. This goes to your former statement about ground being allowed to be one size smaller. The "neutral" is the return path for power, kind of like "negative" is with your RV wiring. In AC household wiring - ground is NOT a path for any power unless there is a problem somewhere. That is why neutral wires have insulation (usually white), and ground wires often do not (if they do it is green). Granted - neutral and ground hook to the same place eventually - but not inside the house other then in the main entrance panel. Branch panels usually require an isolated (non-grounded/bonded) neutral bus-bar. Residential service cables - at least in this century - usually have three wires. Two 120 volt hot legs and one neutral (not a ground).. A real "earth" ground.is usually at the base of the pole and it tied to the neutral with a small bare wire. Often 4 or 6 gauge - even it the neutral is 2/0 or 3/0 gauge. At the house - connected to the main service panel is another real "earth" ground tied to the neutral on that end. A service with #2 neutral and hot legs uses #6 bare ground. A service with up to 3/0 hot legs and neutral can use a #4 bare ground. A service with 4/0 hot legs and neutral can use a #2 ground, etc. Back to the RV and ground symbols. All they mean usually is the negative wiring and whatever is used for a common carrier -like the steel frame. Has nothing to do with AC wiring "fault" grounds. That being said -since RVs often have DC and AC wiring -the chassis becomes a real "earth" ground for safety reasons once it is plugged into shore power somewhere. Also when plugged into a portable generator IF it is grounded like recommended but often not done. Just keep in mind that "chassis ground" in DC wiring has little to nothing to do "earth ground" in AC wiring. The former carries power. The latter is not part of a normal circuit and is a safety feature. To this day - nobody has proven which direction power flows (neg to pos or pos to neg). Engineers had to pick on direction and stick to it for standardization of wiring diagrams. So a negative or ground is used at times for return paths of power although nobody knows for sure if this really happens. I guess it depends if you want to follow the "Electron Theory" or the "Hole Theory." They predict opposite current flow. Neither have either been proven. Back to your converter. I'd wire it for it's max rating unless for some reason - you can't. This way it can work at full potential. In regard to statements like "8 gauge" or "10 gauge" is fine for charge circuits. That is silly. All depends on the current flow demands and length of wire runs. No way around that. That is why solar electric on houses now has gone away from 12 volts and is often over 200 volts DC. Makes wiring those long distances much easier. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 28, 2015 Share Posted October 28, 2015 jdemaris this is a power line neutral it is also a power line ground there is no disputing this please note that the guy line is grounded the neutral is grounded the transformer is grounded the guy lines on all of the poles are grounded they don't put grounding clamps on every thing because it's fun. Yes the house has a ground you think the #4 ground will stand 200 amps if the neutral is lost because that is where the neutral will come from. They are both tied to the same load center ground. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 28, 2015 Share Posted October 28, 2015 The entrance panel has a common ground and neutral a sub panel does not it has an isolated neutral with a load center panel ground two completely different animals power co. wiring does not enter a sub panel. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 28, 2015 Author Share Posted October 28, 2015 Thanks for the input, trying to figure this out has kept me from making any progress for several days. I am having some skin cancer removed tomorrow, nothing serious, but will keep me from doing anything for a few more days. So the electrical like other projects is turning into a long drawn out affair. I shopped a bit for electrical items today and local prices are extremely high and not what I want so will spend some of my recuperation time doing online shopping and trying to figure out my best route with the electrical. Once I have a plan it should go quickly. Thanks Jim Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 28, 2015 Share Posted October 28, 2015 Sorry about the skin cancer I went through the same thing too may years in the southern sun learned my lesson I look like a mime when I'm out in the sun now. Copper wire is expensive be thankful the price has dropped. Home Depot is about the lowest price without an account at a supply house what ever you buy be sure it is stranded wire do not use solid wire. Quote Link to comment Share on other sites More sharing options...
Back East Don Posted October 28, 2015 Share Posted October 28, 2015 Hey Jim I quickly read through the post. Here is a basic drawing I did of the battery hook up I did for someone awhile ago. Don't know if it will make things clearer or muddy the water further. I too like some felt the house battery wiring wasn't up to snuff so I replaced it with some heavier gauge. I'm not sure I still have the Amazon wish list still but will look. I put a type of circuit breaker that will work as a shut off as it allows me to disconnect the battery from any inadvertent load while not in use. I'll see what I can find. Here is the drawing. Good luck with treatment. Quote Link to comment Share on other sites More sharing options...
zero Posted October 28, 2015 Share Posted October 28, 2015 The entrance panel has a common ground and neutral a sub panel does not it has an isolated neutral with a load center panel ground two completely different animals power co. wiring does not enter a sub panel. Yes, I already stated that. The exception is if the branch panel has it's own ground-system (electrodes, well casing, buried metal pipes, etc.). If so, the neutral can be bonded to the ground in the branch panel. This is allowed in older wiring and was changed for "new work" with the 2008 NEC. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 28, 2015 Author Share Posted October 28, 2015 Every bit helps, I do plan on using one of the switch/breakers you posted a pic of. I am doing a quick search and not finding 55 amp DC breakers. Go from 50 to 60 and nothing in between? Jim Quote Link to comment Share on other sites More sharing options...
WME Posted October 28, 2015 Share Posted October 28, 2015 Anything that will trip a 50 amp breaker, will trip a 60 amp breaker. Go with which ever trips your trigger. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 28, 2015 Author Share Posted October 28, 2015 Sorry about the skin cancer I went through the same thing too may years in the southern sun learned my lesson I look like a mime when I'm out in the sun now. Copper wire is expensive be thankful the price has dropped. Home Depot is about the lowest price without an account at a supply house what ever you buy be sure it is stranded wire do not use solid wire. Expensive!! I stopped at Tractor supply for some 14 ga primary wire. $5.99 for 12 feet! I have had a few of these cut off it is likely due to Agent Orange exposure. Jim SW FL Quote Link to comment Share on other sites More sharing options...
Back East Don Posted October 28, 2015 Share Posted October 28, 2015 Just a quick note. You made a comment about the house battery being in the wrong place. From a design perspective it is approximately equal distance from its two charging systems. In my drawing you'll note there are two leads going to the positive terminal of the battery. One from the house charging system and the other from the battery isolator from the truck alternator side. When one system is running, the other is not as I am not likely to be running the engine while plugged in. Also Amazon has #6 & #4 gauge automotive wire for pretty reasonable money along with lugs and just about everything else. Quote Link to comment Share on other sites More sharing options...
zero Posted October 28, 2015 Share Posted October 28, 2015 Every bit helps, I do plan on using one of the switch/breakers you posted a pic of. I am doing a quick search and not finding 55 amp DC breakers. Go from 50 to 60 and nothing in between? Jim Look got the large plastic manually resetting breakers. They come in 50, 60, 70, 80, 90. 100, etc. Not those cheap little auto-reset tin-cans like you'll find at NAPA. Many places sell them and the Chinese ones are less then $10 each. I've got two 60 amp Chinese breakers on my Minicruiser. I also have two extra 70 amp breakers as spares (in case those 60s ever start tripping). So far, it has never happened. I've got #2 copper connecting the isolation relay up front the two house batteries in back. My isolator-relay has a voltage-sensing chip wired to it so it turns itself on an off. By the way - not that you need it . The AC electric panels and Square D type QO circuit breakers sold at Walmart are rated for DC as well as household AC. One of the few out there that are. Big and bulky but if you ever need to do some DC hard-wiring - they are rated for the job. Quote Link to comment Share on other sites More sharing options...
zero Posted October 28, 2015 Share Posted October 28, 2015 Expensive!! I stopped at Tractor supply for some 14 ga primary wire. $5.99 for 12 feet! Jim SW FL Cheaper and better wire at Home Depot. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 28, 2015 Share Posted October 28, 2015 “I'm not trying to nick-pick but since you've been asking questions - might as well get it right. Ground and neutral are NOT the same in household wiring" The white wires are joined to what? Yes that's right the exact buss that goes to the ground it is also joined to the panel case. Where does the neutral wire come from? The power pole. What is it joined to? The earth ground at the pole and the driven ground wire in the box and at the power station ground. When one joins two wires together they become one it's not just a neutral the neutral is not separated from the earth ground. Breaker boxes come with an isolated neutral it is up to the electrician to install the ground screw and add a grounded buss bar to accommodate both the white wires and the ground wires together. So what does it become a neutral or a ground? They are one and the same. When a sub panel is added it is feed with 4 wires not 3 now here is where it gets tricky the added green wire comes for where? It comes from the same buss as the neutral in the main panel and that's grounded we have established that. In the sub panel the ground screw has been removed from the common/neutral/ground buss so only the white wires got landed there including the white banded wire that comes from where? Yes the common/neutral/ground buss in the main panel. Now if the neutral and the ground are not the same it could be proven with a ohm meter at any outlet if they were not the same the outlet ground screw and the white wire would have infinite resistance but we know that is not true. Now because my house panel is behind a 200 amp breaker it is considered a sub panel (there is a reason why I did it that way) note how the ground/neutral/commons are landed ,the added green wire is for the sub panel I’ll toss something out there, power co’s. have been experimenting with elaborate grounding at the power station their plan is to eliminate the power pole neutral and provide the neutral through the house grounding system. The reason for the post, it is best not to assume that someone does not know what they are talking about because you have different opinion. Quote Link to comment Share on other sites More sharing options...
zero Posted October 28, 2015 Share Posted October 28, 2015 The reason for the post, it is best not to assume that someone does not know what they are talking about because you have different opinion. I was not working on any assumptions about anybody. Just posting facts as recognized by National Electric code. Neutral is not the same as "earth ground" even though they are connected together. Usually just at one place in a residential structure with a few exceptions allowed. Also - at least in any state I've installed residential entrance panels - power company wires never come into any box in the house - regardless if the entrance panel or a branch panel. Power company wire is considered "not insulated" even if it is vinyl covered and stops at the mast-head.outdoors where nobody can touch it from ground level. From that point it is homeowner owned wire. Usually 4/0 aluminum (200 amp) nowadays and that is what goes into the main panel. Lots of things we can have opinions about that cannot be proves - like what direction electrons flow IF they actually flow. But when it comes to an "earth ground" and a "neutral" in a household with the 120 volt wiring - it is not a matter of opinion. They serve different purposes. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 29, 2015 Author Share Posted October 29, 2015 Even $5.99 for 25 ft at HD is way too expensive!! Thanks for the pictures, nice setup. Does not leave much room under the sofa! Looking this over I am going to use the 50 amp, one panel mount by the house battery and the rest inline audio types. The inline audio type is being difficult to order, the ones I am finding are being shipped from overseas with delivery dates around the end of Nov. Went to the VA today at 9:30 and was out of there in less than an hour, not a bad procedure. The Dr found 2 more that have to come off at another time! But no pushing, pulling or straining for 2 weeks! Jim Quote Link to comment Share on other sites More sharing options...
jjrbus Posted October 29, 2015 Author Share Posted October 29, 2015 Just a quick note. You made a comment about the house battery being in the wrong place. From a design perspective it is approximately equal distance from its two charging systems. In my drawing you'll note there are two leads going to the positive terminal of the battery. One from the house charging system and the other from the battery isolator from the truck alternator side. When one system is running, the other is not as I am not likely to be running the engine while plugged in. Also Amazon has #6 & #4 gauge automotive wire for pretty reasonable money along with lugs and just about everything else. Mine is no where near equal! Approximate #'s. 33 feet from truck battery and 10 feet from converter/charger. Quote Link to comment Share on other sites More sharing options...
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