Electrical Advice

[Grease&gravel]

I am trying to figure out if I have my panel wired correctly.

I have a 50amp shore power recepticle wired directly into the main of my ac panel that I plug the generator into. Attached is a picture of my panel. I am confused because some people are saying to bond neutral and ground, others say to isolate neutral into the bus bar on the far right and others say to isolate ground to the far right.

I have a ground wire bolted to the frame, and I have a rebar rod to ground the generator.

That aside I have two 12v batteries, a power converter to charge them and I will buy an inverter.


I want to be able to run my AC panel off of the inverter to run a fridge overnight with a less than 2 amp draw and led lighting.

What type of inverter do I need? And how exactly do I tie the inverter into my AC panel?

[Rovobay]

what is the long bare metal copper wire on the far right coming up from the bottom? is it attached to something?

[o1marc]

Originally Posted by Rovobay

what is the long bare metal copper wire on the far right coming up from the bottom? is it attached to something?

Clearly it is not attached to anything. You can see it come out of the conduit clamp and see the other end.

[Willie_McCoy]

Ive been doing a lot of reading on this very subject lately, perhaps this will help


120 VAC in your RV

[Grease&gravel]

It's not attached to anything in the picture but it has since been bolted to the frame and attched to the panel.

[family wagon]

Your wiring is very tidy. Good job.

I have a couple suggestions for changing the wiring of the panel. The bus bars on the left and the right -- the ones where you've landed the neutrals on the left and the grounds on the right -- are for neutrals only. The grounds should land instead on that "other" bus bar at the extreme right, ie the one that's mounted directly to the metal box. The incoming ground wire from the supply cable should land there too, rather than in the lug beside the incoming neutral.

The green bonding screw in the upper left, just below the neutral lugs, should be removed. Its purpose is to short together the grounds and the neutrals. In general this should only be done in a "main" panel, ie the first panel downstream from an electric utility meter.

Since your panel could be powered from a generator or inverter, you'll need to provide a way to get that neutral-to-ground bond connection only when powered from these sources. Some generators have this built in; others do not. You'd have to test your generator with an ohmmeter or simply add a bond of your own. Mike Sokol describes a way of doing this here Generator Ground-Neutral Bonding | No~Shock~Zone and there

https://www.youtube.com/watch?v=M-bTLdMjuqU

The same is true of inverters: some have the bond built in; others don't. Some even switch the bond so that it's connected only when the inverter is running.

It might make sense to choose LED lighting which can run directly from the batteries rather than involving the inverter with it.

Apart from the fridge, will anything else run on the inverter? One option could be to use a switch so that the fridge is powered from the panel or the inverter, and not provide any way of connecting the inverter to the panel.

If the inverter does need to power the panel, one challenge you'll face is that the panel is set up for split phase service (two 120 v hot legs) but the inverters most commonly available are not split phase (they have only one 120 volt leg). You'd need a transfer switch to disconnect both hot legs from the shore power and connect one of them to the inverter. One intuitive way of doing that is to use the shore power cord as the transfer switch: plug it to shore power, to the generator, or to the inverter. Note that every other circuit breaker slot in the panel would be unpowered when using the inverter.

[Grease&gravel]

Thanks for walking me through this, I appreciate it. From research it seems that auto transfer switchs are meant for switching from a generator to shore power. Could I possibly wire the shore power recepticle for the generator into one input of the switch and wire the inverter into the other and then wire the swith into my mains?

I don't want to have to run an external cord to plug my inverter into my shore power inlet.


I don't think I did enough research before throwing a panel in there.

But yeah just fridge and lights. But I have 350 amp hours so
I could probably run a little more. I don't want to overdue it but I want to avoid having to have the generator on 24/7.

[BlackJohn]

Great pic and really neat connections, but a few questions for you.
Not saying I agree with the connections till I know more about your equipment, the panel, the generator.


Can you provide a pic of the panel cover so I can read the nameplate specs? Need amperage and voltage specs because I can't tell from the panel pic you provided if it is 110v ac only or 110/240v ac and at what amperage.


So you are tied to the generator only right now? I presume it has a 240v ac output?
How many amps does it deliver? What make?


I see you have used 20 amp breakers for the branch circuits butt say you are only using one fridge some lighting, power etc for kitchen appliances? No air con? No electric heat or water heater?
If so, your breakers should only be 15 amp if your wiring is 2c/14awg on those 4 breakers showing. If the wiring is 2c/12awg then unless you have a 20 amp load , you should use 15amp breakers as it is designed for.
With an air con you might need a 20amp breaker, more than likely 30AMP breaker.


Do you ever expect to use shore power at 50amps,? That is 50 amps at 110v ac as are most campground pedestals, not 2 legs at 50 amps which you might need and find in a park for high end rv's.


I asked for a panel pic of the cover because I see you tied the red and black onto 2 breakers. They come from the gen and should supply the whole panel. As it is, they are doing nothing it seems. They or at least one of them should go to that lug in the upper right corner area I think but I would need to ring that panel out with an ohm meter to be sure. Never seen it done like yours is before. You have fed the load side of those two 50 amp breakers. Being on those lugs does not provide power if the bus bars them selves aren't powered up, which they would be if you determine if that lug in the upper right feeds the panel power busbars.


That bare ground is now connected to the panel? Got a pic? You need to grind the paint off the enclosure where the connection lug is.


Are the main panel lugs made for copper/aluminum use and stamped as such? If they are aluminum you will need to use some Pentrox to ward off problems associated with two dis-similar metals.


Sorry for the questions but hard to advise without the extra information under your circumstances.


John

[Grease&gravel]

I'll do it later, It is 125 amps that's all I know.




Predators 3500 watt 28 amps.



Ac is 15 amps and water heater is 6 amps but I never plan on running it off the batteries.

I used 12/2 and used the 20 amp breakers because they came with the panel



I don't ever expect to use 50 amps....I just wanted to wire it that way in case I'm in a place that had 50amps only. I know that you can run 30 off 50 but not 50 off 30. Should I just switch to a 30 amp shore power recepticle?


This set up does work I have already used the generator to power it. I planned on tying the hot wires to the two main lugs in the back but my panel didn't come with the wire holders and nuts to screw the wires to them..


That bare ground is now connected to the panel? Got a pic? You need to grind the paint off the enclosure where the connection lug is. It's already connect thats an old pic.



They are aluminum, I have anti-ox on them

[TheHubbardBus]

Originally Posted by Grease&gravel

I have a 50amp shore power recepticle wired directly into the main of my ac panel that I plug the generator into. Attached is a picture of my panel. I am confused because some people are saying to bond neutral and ground, others say to isolate neutral into the bus bar on the far right and others say to isolate ground to the far right.

Without commenting directly on your specific setup, you never should have ground and neutral bonded in more than one place, and that place is the AC source itself. For shore power, the AC source is the panel of the receptacle you're plugging into. With a generator, it's either the generator itself if you can/have bonded neutral to ground there, or a transfer switch that does the same for you. Note that if you're utilizing a transfer switch that does bond the two, you want to make sure the generator is not also nuetral/ground bonded.

If/when you're running an inverter, then it should - when supplying AC - automatically bond neutral & ground. Once again, make sure it's only in one place.

I have a ground wire bolted to the frame, and I have a rebar rod to ground the generator

No problem here, just be aware that grounding the generator is not a requirement for the ground system to help keep you safe from shock. In the case of a ground fault (hot wire touches something it's not supposed to), in a properly-grounded system, the current running back to the source (via ground wiring, which eventually bonds to neutral, completing the circuit) bypasses any loads, resulting in high current, which then trips your breaker, which in turn is designed to prevent you or your rig from turning into a charcoal briquette. A ground rod is more about lightning protection when talking about generators, particularly of the portable variety, and how much protection you're actually getting by using a piece of rebar is debatable. The term 'ground' is unfortunate, as it confuses two subjects that aren't really connected. Long story short, it won't hurt (as long as you obey the bonding rules), but if you failed to hammer it in one night, it likely wouldn't be end of days.

[Grease&gravel]

I just remembered why my red and black phases go into the breaker instead of the lugs.... because I couldn't figure out how to have a main breaker to switch them off, so I have them coming into the 50amp breaker so I have the option to turn power off to the whole panel.

There were so many panels and I didn't know which one to buy. I should have bought one with it's own main breaker switch on top apart from the other breakers.

[joeblack5]

I can read all about bonding in the electrical code book. So what happens with a bonded bus chassis if the person touches the life wire when he is barefoot and on the metal?

Funny enough in Europe this bonding is strictly forbidden... The electric company supplies a fourth line which is a true ground and one that is a true neutral ( return line). With the lower us voltage and the cheapness of the power company they invented bonding.

Then in the us bonding they dare to add a ground pin. I guess they never ask themselves want would happen if the neutral wire fails. It means that the return current now has to go via the bonding to the groundpin. But the ground pins resistance to ground is way to high to handle a lot of current. The result is that all the metal appliances will be at a voltage between 120 vac and 0 volt relative to ground . all depending on the quality of the earthpin.

In europe the main breaker has a 33 milliAmp gfci built in. The neutral and ground are only bonded indeed in the power plant itself..

Incase of our mobile conductive bus construction I would never bond neutral and ground together. Instead I would megger that they were completely separated.

Johan

[family wagon]

Originally Posted by BlackJohn

I asked for a panel pic of the cover because I see you tied the red and black onto 2 breakers. They come from the gen and should supply the whole panel. As it is, they are doing nothing it seems. They or at least one of them should go to that lug in the upper right corner area I think but I would need to ring that panel out with an ohm meter to be sure. Never seen it done like yours is before. You have fed the load side of those two 50 amp breakers. Being on those lugs does not provide power if the bus bars them selves aren't powered up, which they would be if you determine if that lug in the upper right feeds the panel power busbars.

If one looks carefully at the photo -- I had to click three times to open the photo and get it full size -- there's a label just barely legible above the 50A two-pole breaker. It says "Back Fed MAIN BREAKER this slot ->." Some circuit breakers are listed for back-feed use, so this is a legitimate albeit unfamiliar way of feeding a panel. We also can see that there are two separate bus bars, so it must be a 240 volt split phase panel.

Originally Posted by Grease&gravel

From research it seems that auto transfer switchs are meant for switching from a generator to shore power. Could I possibly wire the shore power recepticle for the generator into one input of the switch and wire the inverter into the other and then wire the swith into my mains?

I don't think I did enough research before throwing a panel in there.

The panel is fine -- all panels are going to be more-or-less similar to this one. Things get complicated only because we want to power our buses from two and sometimes three different sources.


Some panels support an accessory called an interlock. It's a sheet metal apparatus that goes between the handles of the main breaker and one branch breaker. It's a cheap way of providing a manual transfer switch: a generator back feeds into the interlocked branch breaker. The interlock assures that only the main breaker or the generator breaker (ie not both) may be turned on. If there's an interlock available for your panel it could be used for the switching between shore power or local (generator/inverter) power. Then an additional transfer switch, whether manual or automatic, could select between the generator and the inverter.


Any way you slice it, to have three source options you're going to need two transfer switches (the interlock counts as one, if it's available for your panel).

[Grease&gravel]

So I'm going to unbond all neutrals and grounds and I understand to only bond neutral and ground at the power source.


I never plan to have shore power and genny plugged in simultaneously. I will manually plug in shore or genny.

I want to be able to power one phase of the ac panel for the fridge.....do I need to have a transfer switch between the panel and inverter? And then I wire the inverter in on a breaker on the same side that the fridge is on?

[JDOnTheGo]

Originally Posted by Grease&gravel

I never plan to have shore power and genny plugged in simultaneously. I will manuall plug in shore or genny.

I want to be able to power one phase of the ac panel for the fridge.....do I need to have a transfer switch between the panel and inverter? And then I wire the inverter in on a breaker on the same side that the fridge is on?

You previously asked about transfer switches and the above is similar. With automatic transfer switches, you don't need to worry about them - that is the beauty. They each have a "default" input - if power is available it is passed thru. Otherwise, if power is available on the "other" input, it is passed thru. Power can be available on both without harm.

My wiring diagram may be too complicated but take a look (here). This is an example of powering a distribution panel from a variety of sources, including inverter. The first transfer switch is between shore power (default) and generator (50 amp, two legs), the second transfer switch (one leg) is between shore/generator (default) and inverter. I think that answers your question above.

[david.dgeorge07]

Invest in a combination charger, transfer switch, inverter.

All in one box makes many things very simple. Then all you have to worry about is switching between shore and genny.

I just ran a line to my genny that terminates by my shore inlet and I have a plug that I switch back and forth inside the bus for transition between shore and genny, but auto transfer switch in inverter charger makes everything switch seamlessly from battery and back so you never see the power go off and charging happens automatically once non battery sources are available.

[BlackJohn]

Family Wagon


"If one looks carefully at the photo -- I had to click three times to open the photo and get it full size -- there's a label just barely legible above the 50A two-pole breaker. It says "Back Fed MAIN BREAKER this slot ->." Some circuit breakers are listed for back-feed use, so this is a legitimate albeit unfamiliar way of feeding a panel. We also can see that there are two separate bus bars, so it must be a 240 volt split phase panel."


I noticed that label but was unable to read it even when enlarging the pic and forgot to ask the OP what or how it read.

Never knew this was an accepted practice having never come across it before.
Missed the separate bus bars too so asked for verification from the OP.


Better get my eyes checked.


John

[kazetsukai]

Originally Posted by Grease&gravel

I just remembered why my red and black phases go into the breaker instead of the lugs....

On that note, most inverters (not sure about generators) are single phase. Is there even a safe way to wire a two phase panel with single phase AC? I went with a split phase inverter that has a built in ATS function, so I'm just curious.

Originally Posted by Grease&gravel

I should have bought one with it's own main breaker switch on top apart from the other breakers.

I did the same thing, I'm not sure why you think this way. Both approaches yield the exact same result.



I have 8 breaker slots on a QO panel without a main breaker. One two-position breaker for the (inverter) in, another 2-pos for the washer/dryer, another 2-pos for the mini split, and then one single position breaker for each side of the bus' outlets. I ran 20A service to the all of the (GFI) 110 outlets.