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Electric plan review (I know, another one!)

8K views 37 replies 8 participants last post by  momasarg 
#1 ·
Hello and I just want to say how awesome this forum is and especially the detailed information on here!
I’m working on our Promaster layout, electric and plumbing, and when that’s done, my partner will take over the actual construction, since he has quite a bit of experience with that.

I think I’m pretty close to something of value, but would really appreciate any input, observations and ideas so I can wrap this up and move on to the plumbing. Wheee.

Note: Our 2019 PM is a 159” high roof in a dark granite grey. My partner and I have named it Grey Matter ;), and I even made a page for it on my art website so people can follow along as we make a part time home for our hiking and travels. We decided we have the time and energy to do this project, rather than pay more for a lesser quality result.

A couple of items on our wish list:
- some solar, we probably would be off grid 3 days, longer if possible.
- probably propane for cooking and a water heater
- shower and portapotty were my must-haves
- a 12v fridge
- microwave (for reheating only)
- electric water pump
- we want to leave room on the roof for a (tiny) deck up there. That means only two solar panels, a maxx air fan and a future air conditioner up top. (it’s possible the future air conditioner will be shore power only)

Here’s my diagram so far- (attached)

Thanks in advance for helping us move from paper dreams to actual road time!
 

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#2 ·
Electrical



Hi Artbybam

I took a brief look. Im no expert & you will probably get more ideas/opinions here. Here are my thoughts

The Victron battery monitor gauge with have a shunt (battery side & “in my case ground to chassis”). Without a “common” ground (I used the chassis) you cant complete the circuit for the battery isolator ARC

The Victron Battery Monitor with bluetooth is a nice feature to get the info on your phone & also to setup

Im not familiar with much of the equipment you have choose. I can tell you I bought a charger/ac panel/dc panel all in one box.


http://parallaxpower.com/power-centers/


Have fun with “Grey Matter”
 
#4 ·
...
The Victron battery monitor gauge with have a shunt (battery side & “in my case ground to chassis”). Without a “common” ground (I used the chassis) you cant complete the circuit for the battery isolator ARC

The Victron Battery Monitor with bluetooth is a nice feature to get the info on your phone & also to setup

Im not familiar with much of the equipment you have choose. I can tell you I bought a charger/ac panel/dc panel all in one box.
http://parallaxpower.com/power-centers/

Have fun with “Grey Matter”
I see that detail in the Victron install guide. I didn’t show the complete connections for the Victron or the other monitors. Plan to show with more detail later.

The parallaxpower center looks like a nice option! I’ll check it out further.
Thanks RV8R!
 
#5 ·
These kind of visual diagrams are so helpful for my inner artist that likes “pictures”. :D

Hope to have my next electric layout look more like this.
Thanks!
 
#6 ·
A Photo of My Install

I dont have a good photo handy of my install, but attached is an earlier photo before I “tidied up” the install

I will try to describe some of the runs here briefly;

Promaster Engine Alternator Charging;
existing 70Amp fuse on starter battery to Victron Battery Combiner (in photo) to switch

Positive House Battery (in photo) Red;
Battery post to 200amp fuse on battery post to switch

Negative House Battery (in photo) Black;
Battery post to “battery side” of the Victron BM shunt / other side of the shunt to ground “chassis”

Other Wiring Methods of My System;

1) The Manual switch has 4 functions; All Off / House Battery On Only / Started Battery On Only / Both House & Started Batteries On

2) The Manual switch has 3 lugs; battery lug 1 / battery lug 2 / load (which goes to my positive charge bus)

3) My Positive Charge bus has a 30amp fuse & then the positive red wire to my DC Panel

4) I used the “Ground Side” of my Victron Shunt as my Negative Charge Bus (I only have a couple of rings on it so I did not worry about an individual Negative Charge Bus)

Bus / Bus Cover / Battery Fuse Holder / Battery Fuse; All Marine Grade “Blue Sea”

All my wire is marine grade “corrosion resistant”

Some of the items & quality of the parts is not necessary. For me I look at the cost benefit & make decisions - I even get some of the decisions correct in my mind.

I tend to “over build” as a method of insurance (real or false one either finds out or never does). I try to have 360’ forethought, but have many blind spots.

You will get loads & loads of information on this forum (we all have opinions).

If I ever build another van (& I intend to as I am going to use up & mile out my 2018 as fas as I can), I could literally build it in 1/3rd of the time I took (which in my case was about 5 or 6 months in my spare time “part time”). Research & Understanding is the key. Don't be afraid of mistakes as we all DIYers make them (heck the Professionals all make them & the good Professionals are expert @ hiding their errors)

IMO one of the biggest advantages of DIY is the knowledge you have once you have completed (btw you never are completed)>:D

Welcome to this Wonderful Sharing Community & All My Best to You for Your Buildout !!
 

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#9 ·
I will try to describe some of the runs here briefly;

Promaster Engine Alternator Charging;
existing 70Amp fuse on starter battery to Victron Battery Combiner (in photo) to switch

Positive House Battery (in photo) Red;
Battery post to 200amp fuse on battery post to switch

Negative House Battery (in photo) Black;
Battery post to “battery side” of the Victron BM shunt / other side of the shunt to ground “chassis”

Other Wiring Methods of My System;
1) The Manual switch has 4 functions; All Off / House Battery On Only / Started Battery On Only / Both House & Started Batteries On
2) The Manual switch has 3 lugs; battery lug 1 / battery lug 2 / load (which goes to my positive charge bus)
3) My Positive Charge bus has a 30amp fuse & then the positive red wire to my DC Panel
4) I used the “Ground Side” of my Victron Shunt as my Negative Charge Bus (I only have a couple of rings on it so I did not worry about an individual Negative Charge Bus)

Bus / Bus Cover / Battery Fuse Holder / Battery Fuse; All Marine Grade “Blue Sea”
All my wire is marine grade “corrosion resistant”

Some of the items & quality of the parts is not necessary. For me I look at the cost benefit & make decisions - I even get some of the decisions correct in my mind.

I tend to “over build” as a method of insurance (real or false one either finds out or never does). I try to have 360’ forethought, but have many blind spots.

You will get loads & loads of information on this forum (we all have opinions).

If I ever build another van (& I intend to as I am going to use up & mile out my 2018 as fas as I can), I could literally build it in 1/3rd of the time I took (which in my case was about 5 or 6 months in my spare time “part time”). Research & Understanding is the key. Don't be afraid of mistakes as we all DIYers make them (heck the Professionals all make them & the good Professionals are expert @ hiding their errors)

IMO one of the biggest advantages of DIY is the knowledge you have once you have completed (btw you never are completed)>:D

Welcome to this Wonderful Sharing Community & All My Best to You for Your Buildout !!
Appreciate the image and detailed info with it. I’ll sit down and see what I can absorb.
We do want to overbuild, as well as do it correctly. Although we are getting a bit antsy to get started on the “good stuff”.
I know, patience and planning pay off!

I did find some info on the fuel tank aux pickup. That makes me reconsider a webasto heater, for 12v usage.

Thanks for the welcome! There’s lots of good people on here and I’m looking forward to finding out how much I don’t know!
 
#7 · (Edited)
I re-read your design parameters;

I really think you would benefit from reviewing SteveSS build of “Shiny’s” buildout

I have personally seen “Shiny” recently as Steve & I live in the same city

Steve has lots of RV experience & has done a fantastic job of design & build. If I wanted a shower I would really consider his design, as once I saw it in person it made a lot of sense to me. Steve is also a very helpful guy & very humble




https://www.promasterforum.com/forum/showthread.php?t=61554

Check it out if you have time
 
#10 ·
I re-read your design parameters;

I really think you would benefit from reviewing SteveSS build of “Shiny’s” buildout

I have personally seen “Shiny” recently as Steve & I live in the same city

Steve has lots of RV experience & has done a fantastic job of design & build. If I wanted a shower I would really consider his design, as once I saw it in person it made a lot of sense to me. Steve is also a very helpful guy & very humble

https://www.promasterforum.com/forum/showthread.php?t=61554

Check it out if you have time
On it! With so much good info on here, it gets a little challenging to know which ones are helpful at the stage we’re at.
Thanks!
 
#8 ·
Energy Management - My Biggest Mistake(s)

I’m working on our Promaster layout, electric and plumbing

A couple of items on our wish list:
- some solar, we probably would be off grid 3 days, longer if possible.
- probably propane for cooking and a water heater
- shower and portapotty were my must-haves
- a 12v fridge
- microwave (for reheating only)
- electric water pump
- we want to leave room on the roof for a (tiny) deck up there. That means only two solar panels, a maxx air fan and a future air conditioner up top. (it’s possible the future air conditioner will be shore power only!
One of My Biggest Mistakes in My Build; Was not understanding Energy Management. If I were to do it again I would separate my Needs/Wants into the following categories & solve the “Energy Management Requirements”

The Type of Energy & the Storage Tank; The house batteries are just a storage tank that you can only use a percentage of to get longterm use:eek:

Energy Tanks; House Batteries / Propane / Diesel / Gasoline / Other ?

btw your PM most likely has a aux fuel pickup already in your factory tank

All Energy Tanks have pros & cons. I prefer propane tanks to be outside the van, but have not come across a magic solution to my “want/preference”


Electrical;

12 volt (easy & I made everything 12volt that I could - I also have a converter not an inverter. A converter takes 120v shore power & converts it to 12 v)

120 volt (IF inverted from 12v batteries “very expensive & need loads of battery power if using inverters to “heat” or “cool” ) 2000W of 120v from a 12v battery (take the W divide by 10 to be safe) = 200amps :eek: btw it does not exactly work like that & some here may fault me for providing a overly simplified formula that is not accurate, however 12v inverted to 120v depending on the “efficiency” of the inverter, blaa, blaa, blaa you are going to need a huge battery bank & ability to “fill the tank”. I finally realized this too late in my build & the scene from “Jaws” came to my mind - You Are Gonna Need a Bigger Boat”


Something I am considering for Hot Water;

The Isotherm Spa Hot Water Tank; This uses heat from your engine to heat the hot water & also has a 700W 120v electric heating element. Again, check out SteveSS Shiny buildout


Conclusion; Energy Management & Design - Very Important
 
#11 ·
One of My Biggest Mistakes in My Build; Was not understanding Energy Management. If I were to do it again I would separate my Needs/Wants into the following categories & solve the “Energy Management Requirements”

The Type of Energy & the Storage Tank; The house batteries are just a storage tank that you can only use a percentage of to get longterm use:eek:
Energy Tanks; House Batteries / Propane / Diesel / Gasoline / Other ?

All Energy Tanks have pros & cons. I prefer propane tanks to be outside the van, but have not come across a magic solution to my “want/preference”

Electrical;
12 volt (easy & I made everything 12volt that I could - I also have a converter not an inverter. A converter takes 120v shore power & converts it to 12 v)

120 volt (IF inverted from 12v batteries “very expensive & need loads of battery power if using inverters to “heat” or “cool” ) 2000W of 120v from a 12v battery (take the W divide by 10 to be safe) = 200amps :eek: btw it does not exactly work like that & some here may fault me for providing a overly simplified formula that is not accurate, however 12v inverted to 120v depending on the “efficiency” of the inverter, blaa, blaa, blaa you are going to need a huge battery bank & ability to “fill the tank”. I finally realized this too late in my build & the scene from “Jaws” came to my mind - You Are Gonna Need a Bigger Boat”

Something I am considering for Hot Water;
The Isotherm Spa Hot Water Tank; This uses heat from your engine to heat the hot water & also has a 700W 120v electric heating element. Again, check out SteveSS Shiny buildout

Conclusion; Energy Management & Design - Very Important
Same here for the propane. We’ll probably start with the butane or small propane one burner for cooking.

Great - now I’ll research converter vs inverter!:nerd:

Hot water - also looking at options.

So many decisions to make, so that the ‘bigger boat’ isn’t needed!

A couple points - I probably bit off more than we needed for our first one. But hey, go big or go home? :D
Think we’ll take it out for a few days before we get too far along and see if it’s going to work per the plan.

I’m off to check out SteveSS.
 
#12 ·
Converters and Inverters are completely different things.

Most converters do several jobs and make installing a complete electrical system easier. They have been around in the RV world for perhaps 50 years but new ones are much more sophisticated.

First they take a 120 volt input (through a breaker) that can serve appliances and outlets when plugged in to shore power.
Second they have spaces for several breakers to make the output safe.
Third they have a power supply that can charge the batteries, new ones can handle most battery types.
Fourth they accept power from the batteries (and power supply if plugged in) and feed that through a set of 12 volt fuses to safely supply your 12 volt needs.
Fifth they allow for proper grounding of the shore power- this is not a trivial issue.

These things are very inexpensive for what they do, are super reliable, and compact. They generally do not invert 12 volt dc to 120 volt ac. That is an inverter.

Here is my converter. 30 amps should cover you even if you run an AC on the shore power.
https://smile.amazon.com/WFCO-Arter...RV+converter&qid=1560704020&s=gateway&sr=8-27

Here is my inverter.
 
#15 ·
Converters and Inverters are complete different things.

Most converters do several jobs and make installing a complete electrical system easier. They have been around in the RV world for perhaps 50 years but new ones are much more sophisticated.

First they take a 120 volt input (through a breaker) that can serve appliances and outlets when plugged in to shore power.
Second they have spaces for several breakers to make the output safe.
Third they have a power supply that can charge the batteries, new ones can handle most battery types.
Fourth they accept power from the batteries (and power supply if plugged in) and feed that through a set of 12 volt fuses to safely supply your 12 volt needs.
Fifth they allow for proper grounding of the shore power- this is not a trivial issue.

These things are very inexpensive for what they do, are super reliable, and compact. They generally do not invert 12 volt dc to 120 volt ac. That is an inverter:

Here is my converter. 30 amps should cover you even if you run an AC on the shore power.
https://smile.amazon.com/WFCO-Arter...RV+converter&qid=1560704020&s=gateway&sr=8-27

Here is my inverter.
https://smile.amazon.com/WFCO-Arter...RV+converter&qid=1560704020&s=gateway&sr=8-27
Thanks for simplifying. I think!
So, an inverter/ charger doesn’t do the same job as a converter?
You have both an inverter and a converter?
(I think you sent me the same link for converter and inverter.)
 
#13 · (Edited)
Very Helpful RD

I went that route, as after I looked at the space of a dc panel, ac panel, charger/converter it make sense to me

It is typically what RVs use;

Mine is per the following link ( Canadian Amazon - not USD )

[ame]https://www.amazon.ca/Parallax-Power-Supply-Converter-Charger/dp/B00JPJTDI2[/ame]


RD is spot on with regarding to the A/C power “grounding”. Not to be confused with the DC chassis ground

The A/C grounding is tied into your “shore plug” right back to the “shore panel system” (ie not your Van, but the campsite electrical plug)


The panel I bought & most likely RDs utilizes “house breakers” that you can purchase @ a hardware store. I like to stay with mainstream off the self items if I can as they are usually proven, available on vacation, & proven in everyday life in houses without wheels, and competitively priced due to Supply & Demand not specialty industry

Very Good Points; RD made for the use of a “converter/charger/ac panel /dc panel unit.:D:D

I would like to tell you I picked up that advice on the forum, but I did not. I got mine from a very experienced retired electrician friend of mine, who just politely got me on track (think 180 degree turn) with his kind persistent nature & patience. I was lucky to have such a friend, thus Im trying to help out here with the things I have picked up during my build
 
#16 ·
Electricians are good to know!

I went that route, as after I looked at the space of a dc panel, ac panel, charger/converter it make sense to me
It is typically what RVs use;

Mine is per the following link ( Canadian Amazon - not USD )
https://www.amazon.ca/Parallax-Power-Supply-Converter-Charger/dp/B00JPJTDI2

RD is spot on with regarding to the A/C power “grounding”. Not to be confused with the DC chassis ground

The A/C grounding is tied into your “shore plug” right back to the “shore panel system” (ie not your Van, but the campsite electrical plug)

The panel I bought & most likely RDs utilizes “house breakers” that you can purchase @ a hardware store. I like to stay with mainstream off the self items if I can as they are usually proven, available on vacation, & proven in everyday life in houses without wheels, and competitively priced due to Supply & Demand not specialty industry

Very Good Points; RD made for the use of a “converter/charger/ac panel /dc panel unit.:D:D

I would like to tell you I picked up that advice on the forum, but I did not. I got mine from a very experienced retired electrician friend of mine, who just politely got me on track (think 180 degree turn) with his kind persistent nature & patience. I was lucky to have such a friend, thus Im trying to help out here with the things I have picked up during my build

Just as I thought I was getting the hang of it, I realize I’m not there yet. With all my research, I find people call the same equipment by different names!
But I’m very motivated, and haven’t given up.
I do have an electrician friend who is quite busy with other projects right now (in spite of me explaining how important Grey Matter is, haha). Hope to get his input in person.

Guys, thanks again. I’m off to regroup and redo my plan. :)
 
#19 ·
Hi,
There is another common approach to electrical systems in RV that you might want to look into. This uses and Inverter/Charger in combination with a power center (fuse box).


The Inverter/Charger combines and inverter and a battery charger in one unit. When you are not hooked to shore power, the inverter produces 120 volt AC power from your battery, and when you plug in shore power, the Inverter/Charger switches to shore power for your 120 AC, and turns on the charger part to charge your batteries off shore power.


One nice thing about the inverter charger is that it automatically takes care of the issue of bonding the AC neutral wire to the ground wire at the correct point. For safety reasons, the AC neutral wire and the ground should be bonded together at only one point. When on shore power, the bonding point is back in the campground wiring system, but when you are on battery power, the bond point is inside the RV near the inverter. The Inverter/Charger has a built in relay that automatically accomplishes this.


Diagram of a system (mine) that uses an Inverter/Charger setup: https://www.buildagreenrv.com/our-c...y-camper-van-conversion-electrical-and-solar/


Gary
 
#20 ·
Hi,
There is another common approach to electrical systems in RV that you might want to look into. This uses and Inverter/Charger in combination with a power center (fuse box).

One nice thing about the inverter charger is that it automatically takes care of the issue of bonding the AC neutral wire to the ground wire at the correct point. For safety reasons, the AC neutral wire and the ground should be bonded together at only one point. When on shore power, the bonding point is back in the campground wiring system, but when you are on battery power, the bond point is inside the RV near the inverter. The Inverter/Charger has a built in relay that automatically accomplishes this.

Diagram of a system (mine) that uses an Inverter/Charger setup: https://www.buildagreenrv.com/our-c...y-camper-van-conversion-electrical-and-solar/
Gary
Thanks Gary, I had your site saved in my bookmarks already! Looking over your nicely labeled photos of actual construction.
I do plan to use an inverter/charger, pure sine wave, not sure if the ones I’m looking at come with the fuse box.
 
#21 ·
Hi,
I don't think I have seen an Inverter/Charger with fuse panel included -- would not be a bad idea, but don't think there is one offered.


I used this power distribution panel for both the AC and DC: http://www.bestconverter.com/PD5000-30-Amp-ACDC-Power-Control-Panel-_p_27.html#.XQkNLY97mM-



Wfco also makes one: http://wfcoelectronics.com/wp-content/uploads/2016/12/WFCO_63_8930_50_POWER_CENTER_10-with-space.pdf


I think that going for a power distribution center (fuse box) that handles both the AC circuits and DC circuits makes sense, as it means you only have to buy one unit to do both, and its more compact than having separate AC and DC fuse/breaker boxes.



Gary
 
#22 ·
Thanks Gary! Revising plans now! Definitely looking at options.
 
#23 ·
Electric schematic redone

I’ve finally sat down and, using all the great input (I think) have updated my electric needs. I want to have enough charge to power air conditioning.
Give a look, and I’m NOT posting on the fourth, as I hope this won’t be associated with fireworks! :eek:
Thanks again!
 

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#24 ·
Hi,
Couple of thoughts...


For the 12 volt DC panel, one of the loads you have listed is a 12 volt water heater. Unless this is a very low wattage water heater, its probably going to need to be wired directly to the battery via its own breaker.

For the fuse for the whole DC panel, add up all the loads that could possibly be on at one time plus a bit more for future loads and that gives you rough fuse/breaker size -- I use 60 amps.



For the wire size and fuse size for the inverter/charger, the best thing to do is look in the manual -- they should have details on what size wires they want for various lengths. Should be at least (2800 watts/12volts * 0.9 ) = 260 amps, but, go by what the manual says.


There will be a limit to how long you can run the AC from the battery. I think your AC draws about 1200 watts, and the draw from the battery when its running will be about (1200 watts/12 volts * 0.9) =

111 amps (where 0.9 is inverter efficiency). I guess you have 400 amp-hrs of battery, and if you are OK with running them down to 20% state of charge, this gives you 320 useable amp-hrs, or just short of 3 hours of operation. Since the AC probably won't be running all the time, you would probably get more than this, but you have other loads beyond the AC, so this would cut the time some. The smaller you can make the area that you air conditioning the better.


For the shore power wire, you might want to consider using a 30 amp plug and cable. The 30 amp receptacle is available in most shore power pedistals, and if its not available, you can carry an adapter to plug the 30 amp plug into the 15/20 amp receptacle on the shore power pedestal. With the AC, you have some fairly large AC loads, so the extra capacity of the 30 amp cable might come in handy?



That Bluesea ML-ACR is quite a gadget. My first thought was that it was a whole lot of money for a battery isolator, but it does have a lot of nice features that others don't.


The best way to pick the fuse sizes for the van battery to house battery wire would be to ask Renology what they recommend for the maximum charging rate for the two batteries, and size the fuse to that or just a bit more. If you can't get a number out of them, then I think 100 amps would be in the ballpark -- that charging at 0.2C plus some margin. Maybe others with AGM batteries have a better number?


Getting close!



Gary
 
#25 ·
You all probably thought I gave up on this! It has been a while, but I finally found a friend who is revising the electric in his large camper, and he has a lot of knowledge on this. He reviewed, added fuse and wire sizes, and now it feels a lot closer to being done.

I appreciate every single input and hope I’ve addressed most of your suggestions.

Grey Matter is currently away, getting some holes cut in it for the roof fan, AC and a side window. They’ll also throw on the solar panels while they’re up there.
I’m really looking forward to laying out the inside!

One important item is the importance of “short as possible” wire runs from the inverter and the batteries to the bus bars. I thought I could box in the giant batteries behind the driver & passenger seats, but the inverter is quite heavy as well.
It’ll be easier to lay out once the van comes home. I miss having it block my view of the street, lol.

For the 12 volt DC panel, one of the loads you have listed is a 12 volt water heater. Unless this is a very low wattage water heater, its probably going to need to be wired directly to the battery via its own breaker.
Thanks, I meant to remove the water heater listed, will need to research those next!

For the shore power wire, you might want to consider using a 30 amp plug and cable. The 30 amp receptacle is available in most shore power pedistals, and if its not available, you can carry an adapter to plug the 30 amp plug into the 15/20 amp receptacle on the shore power pedestal. With the AC, you have some fairly large AC loads, so the extra capacity of the 30 amp cable might come in handy?
That’s a good idea! Again, not shown on this new attached version, but will revise for the next edition!

So, please see the attached, and feel free to let me know what’s missing!
 

Attachments

#26 ·
Hi,
The diagram is looking good to me.

I do think you should add a fuse/breaker in the line from the house battery to DC panel -- it can be sized for the sum of all the DC loads you could expect to be on at the same time plus some margin.

That MagnaSine inverter/converter looks like a real bomber unit -- should last forever.

If you have not looked for a specific AC panel, I would have a look around and see if you can find a suitable one. I had trouble finding one for my conversion. There are lots of AC panels, but most designed for residential use and are pretty big and clunky. I was pretty happy to find the combined AC/DC distribution panel that is pretty compact.

Please do post the final version of the diagram -- it will a make a good reference -- very clear and easy to read.

Gary
 
#27 ·
I do think you should add a fuse/breaker in the line from the house battery to DC panel -- it can be sized for the sum of all the DC loads you could expect to be on at the same time plus some margin.
Thanks - I wondered if I needed that. Would that go between the bus bar and the DC panel?

I was pretty happy to find the combined AC/DC distribution panel that is pretty compact.
I think I’ve seen your combined panel in my searches. I like that combination.

I’ll be sure to post the finished diagram, and hopefully the physical results won’t take as long as this did! This feels like, measure twice, cut once, except it’s measure 42 times, cut thrice.
Or something. ?
 
#28 ·
#29 ·
No need to spend a lot on a “Fluke” or similar. I have had many and still use my Simpson 360 but you won’t get one of those either.
Perhaps:
Or without the clamp meter:
Harbor Freight often gives this one away free and I have one in every tool set I own. They do work ok for what you want to do.
 
#31 ·
No need to spend a lot on a “Fluke”
I may actually be able to get a Fluke through work - It’s worth checking price there.
they don't provide that is nice for RV electrical systems is a clamp over the wire capability for DC current measurements.
I’ll see what’s available at a reasonable cost.

Thanks for the recommendations - this helps a lot!
Might change my signature here to “shoulda gotta electric degree” ?
 
#30 ·
Hi,
I think you have put enough work into the design that the put it together part will go fast.

The fuse for the DC panel should go as close to the battery/busbar as possible. Reason is that the wire between the busbar and the fuse is not protected -- if it somehow shorts to ground, there is nothing to limit the current it will pull from the battery.

On the multi meter, the cheap $5 ones from Harbor Fright and the like provide a lot of bang for the buck and definitely worth having. The thing they don't provide that is nice for RV electrical systems is a clamp over the wire capability for DC current measurements. After years of using cheap (but fine) meters, I sprung for a Klien CL2000, which is a fine instrument with a lot of handy pro features, but most of all for RV use, it measures DC current with a clamp over feature. I don't think they make the CL2000 anymore, but if you want a premium meter, check over the Klien line and look for the capability to measure DC current with the campon feature -- I think they have dropped in price some. This allows you do do things like seeing exactly how much charging current is on your house battery without having to break any wires. When I die, I'll have my Klien meter buried with me :)

Gary
 
#32 ·
Working on an electric schematic for mine, and have some questions regarding yours.

1) Is a fuse needed between the positive terminal and the bus if there are fuses on every line running out of the bus?
2) No switches?
3) Doesn't the house battery need to be grounded to the starter battery for the isolator to work?
4) What's the purpose in grounding the inverter to chassis?

I'm thinking of providing a kill switch between the battery and negative bus. My thinking is this would completely shut down the system including ground. Like removing the negative terminal first, but without having to remove the negative terminal.

I knew nothing about circuits a few days ago so trying to figure it out.
 
#33 ·
1) Is a fuse needed between the positive terminal and the bus if there are fuses on every line running out of the bus?
I strongly recommend a fuse or breaker as close to any energy source (in this case, the battery) as is feasible. What if you drop a screwdriver across the busbar? or you have an accident and something hits it? Also, you probably want some form of a disconnect on the battery, for storage, and for maintenance.
2) No switches?
I am not sure I understand this question.
3) Doesn't the house battery need to be grounded to the starter battery for the isolator to work?
Yes, there has to be a full circuit (as in, a full circle) for electricity to flow. However, if you are putting in a battery monitor with a shunt, the shunt will connect to the house battery negative, and then the other end of the shunt will connect to your ground bus, which should be tied to the chassis.
4) What's the purpose in grounding the inverter to chassis?
Safety. There are a bunch of posts about this elsewhere on the forum, but I'll recap here: you need a safety "ground" - a place stray currents can safely go. In a house, that ground is the literal ground - a rod outside the house. In a vehicle, that "ground" is the frame of the vehicle. You need to make sure that if there is an accidental connection from 120V to the chassis, the current goes someplace, or you can have the vehicle become charged to 120V relative to the neutral of the system, which means that if you touch your frying pan/curling iron/computer/whatever you complete the circuit and get shocked. Also, when you are on inverter and are NOT connected to external power, you need to bond the neutral to the chassis as well, again so that if there is an unintended connection to the chassis you won't have a "hot skin", and will trip any GFCI you have (you ARE going to have GFCI outlets, RIGHT?!) BUT: when you are on shore power, you MUST NOT bond the neutral, as that is done at the external pedestal. If you have a proper automatic transfer switch it should handle bonding/not bonding for you.
I'm thinking of providing a kill switch between the battery and negative bus. My thinking is this would completely shut down the system including ground. Like removing the negative terminal first, but without having to remove the negative terminal.
If you totally break the connection between the battery negative and everything else that will work for a disconnect just as well as breaking the positive.
 
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