Newbie Electrical Help

[Rusty99]

Hi Folks,

I need your help and input on my electrical diagram. I have scrolled through many posts and tons of youtube video's. Can you review my electrical diagram and let me know what I'm missing or gotten wrong?

Some questions and concerns:

1. My battery disconnect switched is on the negative side. There seems to be no consistent way I've seen
2. Do I ground directly and my battery and also at my progressive dynamics panel/converter? Or just in one place?
3. My wiring coloring from the 30amp inlet was copied from another diagram and I'm very unsure about it.

I welcome your feedback and opinions, I've been stuck on the electrical part of my built for 2 years! If I can get this part sorted I'm on my way to finishing.


Thank you in advance.

Russ

[rjgimp]

I'm certainly no expert and I wouldn't even dream of playing one on tv, but I'll throw a couple observations into the mix.

Regarding the disconnect being on the negative or the positive side, you've likely seen no consistent way to do that because I don't believe there is one. It's like the Ford/Chevy debate. Everyone has an opinion on the matter and no one is likely to be swayed to the other side. I would generally put one on the negative side but there are a great many who would put it on the positive. I've not seen any good evidence that there is a wrong way to do it.

Grounding. Again, I think there are equally large schools of thought on this. I am of the opinion that multiple grounds are never a bad idea.

I don't know about coloring of the 30 amp circuit, but in your post you identify it as an inlet but in the upper left of the diagram you identify it as an outlet. I presume this to be a male plug that you would connect to a 30 amp campground service pedestal?

[troubleScottie]

A couple of things.

The shutoff is often on the positive as if there is a short to ground, your ground shut off switch will not shut off the power. I believe for Lithium batteries, one should have a switch to disconnect the shunt from the battery due to an issue with a full discharged battery and the small amperage draw of the shunt/metering system. I do not believe this is an issue for lead acid batteries.

The AC wires are hot (black), common or neutral (white) and ground (green or bare) for typical ROMEX wire. You can/should connect the AC ground to the battery negative terminal. You can ground it through the frame or via a bus bar or using the ground bus bar in the distribution panel.

Check this site for transfer switch wiring diagram.

There is also a great topic on the pd4045 (http://tnttt.com/viewtopic.php?f=30&t=6 ... 5#p1241628) - connecting AC, shore, converter to the battery, etc.

The 30 AMP outlet is a 30 amp inlet and should connect transfer switch (one AC input).

The inverter's AC side should also be connected to the transfer switch (second AC input).

The transfer switch has an AC connection to the distribution panel (the transfer switch's AC output; the distribution panel AC input)

Your transfer switch is selecting between one of two power sources. You are either using the 30 amp inlet (shore power or a generator) or the inverter.

The inverter is also connected to the battery. I would add a fuse on the positive side just before the inverter. You also want to have a switch for the battery positive to the inverter, so you can turn off the inverter when not in use. Inverters do draw power even without an AC load.

You should read up on inverters here. Lots to think about in terms of power draw, type of inverter ie sine vs square wave, etc. Due to the small size of the batteries, people often do not attempt to run the AC side via an inverter. An inverter can be plugged in via a DC outlet to run small AC devices for short periods. And unplugged when not in use.

I would also add a fuse on the positive terminal of the battery.

Grounding to the frame is fine. However be aware, if the trailer is screwed together, different parts of the frame may not be electrically connected to each other. People often use two wires for each DC appliance. Not really that much more expensive and it ensures a ground.

I would use only GFCI AC outlets. The cost differential is pretty small. Think like you are using AC power in a bathroom. Running water everywhere. One might think about GFCI circuit breakers - belt and suspenders solution.

[Rusty99]

I'm certainly no expert and I wouldn't even dream of playing one on tv, but I'll throw a couple observations into the mix.

Regarding the disconnect being on the negative or the positive side, you've likely seen no consistent way to do that because I don't believe there is one. It's like the Ford/Chevy debate. Everyone has an opinion on the matter and no one is likely to be swayed to the other side. I would generally put one on the negative side but there are a great many who would put it on the positive. I've not seen any good evidence that there is a wrong way to do it.

Grounding. Again, I think there are equally large schools of thought on this. I am of the opinion that multiple grounds are never a bad idea.

I don't know about coloring of the 30 amp circuit, but in your post you identify it as an inlet but in the upper left of the diagram you identify it as an outlet. I presume this to be a male plug that you would connect to a 30 amp campground service pedestal?

Thanks Rob for your reply, Yes you are correct - it should have been labelled as a 30 amp inlet

Any input on having a fuse after the battery disconnect switch? How would I size this fuse considering I have 2 x 6 Volt Batteries in series?

Cheers,
Russ

[GTS225]

Thanks Rob for your reply, Yes you are correct - it should have been labelled as a 30 amp inlet

Any input on having a fuse after the battery disconnect switch? How would I size this fuse considering I have 2 x 6 Volt Batteries in series?

Cheers,
Russ

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Russ; Are you planning to run a 120V, 30 amp, or a 240V, 30 amp supply? If 120VAC, then you will use a white for the neutral, black for "hot", and a green colored,or bare copper for the ground. If it's a 240VAC, then black and red for the "hot" conductors, white for the neutral, and green/copper for the ground. If the panel in your camper has separate lugs for neutral and ground, use them as intended. If not, then tie the neutral and ground together in the panel only. I recommend that you hit up a local electrical supply house for your inlet, and specifically get a male plug to mount in the camper. If you use a female receptacle for your inlet, then your umbilical cord must have a male on both ends, which is quite hazardous, if not downright dangerous. I know, it's so easy to hit a big box store for your needs, but they don't have the selection of plugs and receptacles that a dedicated supply house has available. (I recently had to do just that on my sister's food vending trailer.)

As for the fuse, it depends on the distance between your supply receptacle, and the disconnect/master switch, or main breaker. If your supply receptacle is in the front left, and your main or panel is back in the galley, I would suggest your fuse goes as close to the supply receptacle as possible. My thought process is that sometime, your wiring between the receptacle and the main might become worn, chaffed, or pinched from chassis movement. It could be possible to then plug in to shore power, and have your chassis then charged hot, should any of your grounds give out, which is a very dangerous and deadly condition. With the fuse right at the receptacle, it will react to the condition by opening the circuit and saving lives. That would strand you without the use of shore power, but it would be a small cost if a child were to contact the wrong areas and get electrocuted.

Not trying to scare you away from installing an AC supply, just advising you as to the potential hazards of something none of us can actually see.

Roger

[tony.latham]

Code: Select all

Any input on having a fuse after the battery disconnect switch?

The fuse should be as close to the battery as possible and sized to protect whatever wire you choose to run.

https://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity



T

[pchast]

That fuse..........
It needs to disconnect the battery circuit...
It needs to be either on the positive terminal.
Or in the negative side before the ground makes a circuit!

Your diagram is incorrect in that there could be a battery short
through an appliance or to the ground that would not be protected.

[Rusty99]

Hi Guys,

So I did another electrical diagram incorporating suggestions from troublescottie. I changed the battery disconnect and fuse to the positive side and also some items at the transfer switch.

Hopefully you can review it again and give me some more feedback. I really appreciate the help, it's been amazing to make some progress this weekend with your help!

Just read the posts from Roger (tear drop inspector) - Yes, I am planning to connect to 120 Volt shore power and a dog bone to connect.

Tony and Pete - I will take a closer look at the fuse situation.

But if you can review this latest diagram and provide feedback would be much appreciated.

Cheers,
Russ

[Tom&Shelly]

If the panel in your camper has separate lugs for neutral and ground, use them as intended. If not, then tie the neutral and ground together in the panel only.

Hi Roger,

This is the 2nd time in a few weeks in this forum I've seen a comment about tying the neutral and ground together in the panel of the camper. With respect, I don't think that's an approved or safe practice. The ground and neutral are tied to together externally. Here's what Mike Sokol had to say about it:

http://noshockzone.org/generator-ground ... l-bonding/

I agree with the rest of what you say.

Tom

[Rusty99]

Would be great if somebody could have a look at my latest wiring diagram and give some feedback. Thanks in advance!

[Tom&Shelly]

Would be great if somebody could have a look at my latest wiring diagram and give some feedback. Thanks in advance!

I think it looks right now. I'm glad you decided to put the fuse and cut off switch on the positive side of the battery. The way you had it, the ground came before the fuse which, as others have pointed out, isn't good if a frayed positive wire made contact with the frame.

Of course, depending on how many 12 volt lights, appliances, etc. you have, you may want multiple runs from the PD4045, with separate fuses for each run.

Tom

[pchast]

Looks good to me now.

[GTS225]

Hi Roger,

This is the 2nd time in a few weeks in this forum I've seen a comment about tying the neutral and ground together in the panel of the camper. With respect, I don't think that's an approved or safe practice. The ground and neutral are tied to together externally. Here's what Mike Sokol had to say about it:

http://noshockzone.org/generator-ground ... l-bonding/

I agree with the rest of what you say.

Tom

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OK, Tom; I see where this is going. The link you posted has correct advice. My advice would be correct, if this was a stand-alone system with no provisions for shore power. As it is, there is a shore power need, so yes, the ground and neutral should not be bonded in the panel, because it should already be bonded in the supply side's panel.

In any case, the point is moot, as he's doing 120VAC, not 240.

Sorry about that, my head was a little foggy from being plugged up with a head cold.

Roger

[DWT77]

Russ here is how I have mine drawn up. There are a couple of tweaks I could make here and there on it. For instance move the fuse on the other side of the cut off switch or add a ground from the battery to the chassis. So use this at you own risk but maybe it will help you out since we have somewhat of a similar set up.

[featherliteCT1]

DWT77,

Nice wire diagram.

Question: Do you, in fact, have have both your DC negative buss bar and the negative side of the Ctek unit wired directly to the negative post of your battery, as shown in your diagram?

I could be wrong, and am still learning, but I thought that the only wire that should be attached to the negative post of the battery is the negative wire to the shunt with all negative DC loads attached to the other side of the shunt, so that the Victron monitor can read all amps running in and out of the battery from all sources.

Thanks for sharing.