[TomW]

Any takers on the question regarding using #10 lug on a #8 screw terminal?

The anal engineer is saying you didn't give enough information.

A Molex 19193-0202 is a brazed lung ring terminal, so insulation on.

That is a #10 lug hole for 8 gauge wire.

The #10 lug is designed for a 0.198" +- 0.003" hole.

A #8 screw terminal is 0.164" diameter; so a lug would have a 0.168" hole.

So yes, you could screw it down, but if that buss bar had 0.400" spacing for those screw holes, I'd highly recommend that a Molex 19193-0200 be used on that #8 wire!

Both of those part numbers will have lug widths of 0.379" Max So when you use too large of a terminal rather than being flat on your buss bar, that 0.030" spacing can bite you in the rear. Two adjoining holes, with #8 screws, but #10 holes means one lug can "over lap" the next one. It will seem "good enough" but with time and vibration cause you grief in trouble shooting.

So for 99 out of 100 times over the life of a vehicle you'll never see an issue. That 1% may end up being a case study for a NTSB accident.

Personally, NO! Use the correct lug for the correct screw. Sadly we could spend an 8 hour class on this just subject.

Does that answer your question?

 

[TomW]

Actually, I just found this online.
https://www.westmarine.com/buy/blue...stainless-steel-terminals--335904?recordNum=2

A little pricey, but seems like this should work? Although would like to hear your thoughts on using the one I have (if can manage to not overlap) before buying.

Ouch, that is pricey!

Think in terms of "system approach" How is each circuited fused? Take a look at the 5032 Fuse Block. Not only does each circuit have a fused power line, the bus has a ground. This allows a pair of wires tohave power and return point. I like dedicated return paths.

https://www.bluesea.com/products/5032/ST_Blade_Split_Bus_Fuse_Block

Before you order anything at all, stop and list out everything you need.
What the power Source?
What is the current required to each item?

Often I'll have a list:
Vehicle Battery:

1. Always On
2. Accessory Key Switch (may drop when Engine is cranking)
3. Engine On Power (needs to remain on when Engine is Running)

House Battery - 12V System

1. Master Switch
2. Automatic Charge Switch (energized when engine is running)
3. Fused Panel 12 V

Shore Power: 120V Appliances

1. Generator (invertor) or Shore
2. Master Switch
3. Fused Panel - 120V

Back the bus you mentioned -- we still need a fuse panel, and anytime you see something with #12 screws... RUN AWAY! It is an odd size in the industry. Molex will supply ring terminals for 8 gauge wire is stud 6, 8, 10, and 14! It jumps over 12 in the most common terminal sizes.

Been ages since I have done a lot of this. Some days I remember the most minute details, other times I am hard pressed to remember my own birthday!

 

[TomW]

Ay Carumba.. I went back and captured the diagram so I can keep it open in another window.

2000W Inverter, 12V Source 80% Efficiency -- 208Amp Load. You don't want to run that through a buss bar rated at 150Amp. I messed up looking at that. Makes a little more sense now that I look back at your fuses and wiring.

I suspect you are planning around 1400W being the largest 120V Appliance, but you need to have two busses or a custom copper buss bar (about 1" x 0.25" thick) with these loads.

EDIT: I had over looked the 2000W Inverter current requirements.

 

[TomW]

Also, and this may be elementary, but how did you come up with the 208a load?

For a 2000 Watt Inverter: To get input current, divide by battery voltage (12V) and divide by efficiency (80%). So I get 2000/(12V * 80%). 208Amps (lots of current!) Admitted that is worst case, but gives a ball park current load.

Battery's are 220AH, normally that rate is for a 10 hour constant current discharge. So 22 Amps
over 10 hours. Tojan flooded cells should be limited to about 4x that, or 88 Amps maximum for best life. Hence my concern about drawing than 100 Amps.

looking at the Trojen spec sheet I see they listed 75 Amps for 115 Minutes. Working back from 75 Amps, 12 V battery, 80% efficiency gives a realistic inverter output of 720 Watts. Much more reasonable design load. Small 600W coffee maker, 75W TV, etc are possible with that load.

So now we can plan around the wiring sized for 75 Amp Load. Putting in a 100 Amp Circuit Breaker will protect the wire from burning up, and should prevent nuisance trips (inrush maybe an issue).

I still need time to figure out the Smart Pass & CTEK D250S, looks like Smart Pass can allow up to 80 Amps of current to flow into the house batteries. The CTEK 250S is for 20 Amps of current.

Something to keep in mind about the battery charging of the house batteries, 80 Amps is maximum, but as the battery voltage comes up, the current drops.

So if we look at that Van Battery to House Battery wire. Maximum is 80 Amps, short duty. We can allow a 10% voltage drop as we want the wire to limit current the the house battery. 6 AWG for the length given would be fine.

Two breakers:
Next to VAN battery: ANL circuit rated for 120 Amps.
Next to House Battery: 100 Amp Circuit breaker:

Source (things that provide power)

1. Van Battery via Smart Pass 80 Amps (maximum, intermittent as this current drops as house batteries are charged up)
2. Solar 20 Amps
3. Ctek 2500 20 Amps

Sink (things that consume power):

1. Inverter 75Amp
2. DC 12 Circuit 21 Amp
3. DC 6 Circuit 25 Amps

Things that can Source or Sink:

1. House Battery By keeping the wire feeding it to 6 AWG, with 125C insulation, it will act like a resistor as it warms up limiting current flow. As you go though the design of the system you I'd keep house batteries to 75 Amp design, 100 Amp peak current.

A 100 Amp Circuit breaker from the house batteries should work fine. I'd use something like this 100 Amp Breaker so if Uncle Fred plugs in his Kirby Vacuum Cleaner when on battery power it trips the breaker.



Hopefully this makes a little more sense in dividing up loads source and sinks to get a better idea of the system approach to everything. On that 6 AWG wire, using rubber adel clamps (MS21919) to hold the wire, as allow it to remain in open air, is a good thing. That wire is your shunt to see the state of the house battery (being charged or discharged).



Take a look at my comments and see if they make sense. Often my mind skips ahead of my fingers, and I make some crazy typo's. Once we are on the same page with source and sink currents, then time to start looking at wiring size and fuses to prevent fires!


On my old race car, no fuses! If a critical fuse blew, we were DNF'd (did not finish). I would splice in fuse able links. 12 gauge circuit had a 16 gauge fuse able link. Learned the wisdom of separate circuits for right and left headlights (rally cars), redundant supply feeds (aircraft), so on. I've been at this electrical stuff I've forgotten more than I have known. So I do screw up and mix things up! Sigh. Good part is I have enough wisdom to realize there is much more to learn!

 

[TomW]

So are you saying I could use 6 AWG wire from van battery all the way to house battery (ie. from van to CTEK; instead of 4awg), from CTEK to positive buss bar; instead of 4 awg), and from positive buss bar to house battery; instead of 1/0 wire)? I think the inverter manual recommends a 2/0 or 1/0 for DC input wire.

On your chart there was 3 ft max between points, hence thinking free air, same location, 6 gauge would be fine. This is true for 80Amps, but I'll back pedal and say "just go with 4 gauge" as you have other locations that should use four gauge. Keep life simple but using just gauge.

Ok, so the 120a breaker next to van battery would be where i now have the 60a breaker? Or after CTEK (where I now have the 130a ANL fuse)?
And the 100a breaker next to house battery would go between house battery and positive buss bar? Also, is the 250a MRBF fuse block that I have in my diagram on the house battery necessary?

130A ANL is too high for a 80 Amp Load. Where does the cable from the VAN battery physical run. Once though a bulk head, or hiding, I like to have that line fused. AMG 100 Amp Fuse is fine (off Van Battery, heading to Smart Pass). Do suspect issues (wondering why the disconnect).[EDIT: Do you suspect encountering leakage issues from the CTECK killing the van battery?] If you want to be able to isolate the Smartpass then just make sure you can easy access and remove the fuse.

On that 250Amp MRBF that maybe a little large.

The 2000W does specify much larger wiring. As I mentioned your house batteries will not like that loading for long. If you had larger batteries, say 500 Ah rated, then I would use the specified wiring and go for it.

We calculated on 75 Amps inverter load to allow 720W of appliances while on battery power. That wired helps make sure the inverter will drop out due to low voltage condition. I'd rather see a 750 Watt Inverter in place, and wired with 4 gauge wire.

For a very nicely laid out wiring diagram, take a look at Orton's web site:
http://www.ortontransit.info/index.php
under drawings he has his Eletrical Diagram.
Very nicely done. Note his comments on the inverter and current ratings. A toaster may only need 1000 Watts, but when first plugged in may need 1700 Watts for 5 seconds. Nicely done!

I suspect every place Orton used 14/2 & 16/2 Ancor Marine wiring we would find printed heat shrink on each end of the cable! Little details like that make life so much easier. I'll be the first to admit a year after building something I have forgotten details! Having a clean, well laid out schematic, makes like so much easier during the build and later for troubleshooting all worth while!

Old Engineering work project. 24 High Capacity Group 31 Optima's rated at 1400cca. 288V system, 1400 Amp short duration (minute) but would typically run for a 100 to 200 Amp discharge rate for commute traffic. Learn by doing! - More than just a motto!

 

[TomW]

While Iike the idea if jumping the van from house batteries in a pinch, I'm wondering if I would need to.

When cranking, the starter will pull about 300 Amps. Normally that is only a few seconds, but maybe 30 seconds for those super cold mornings.

You should never pull more than 100 Amps from a deep cycle house battery. So I don't recommend "fast jumping" but you can use use a smaller gauge wire such 12 gauge to connect to the starting battery to allow the voltage to come up over 10 to 20 minutes.

Left the lights on? Just turn everything off, go get a cup of coffee, and come back and a battery has recovered enough to crank the engine over.

I'd be tempted to add some Anderson 2 gauge quick connector to the side of the stock battery box. Jumper cables, with the matching connector, can be stored under the passenger seat, . If you need a jump on a cold -40F morning, having 20 ft long 2 gauge jumpers are great. Nice thing about having jumper cables like that is your brother will never borrow them!

For those with the Battleborn - lithium iron phosphate battery, remember they do not like to be stored with constant trickle.

 

[TomW]

I have a question regarding using a circuit breaker as an on/off switch. For my inverter, which we will likely not use all that often, I was wondering if it would be okay to just use the circuit breaker to cut off power to inverter. If say 95% if the time i would keep it "tripped" and only reset it on the rare occasions when we use it. Thoughts?

Looking good!

Circuit breakers are not happy switches. You can do it occasionally, but when they fail what a pain to replace.

Orton used the Blue Sea 9009 Switch that is a double pole -- ON OFF ON configuration to swithc between Shore Power and Invertor. Nicely done.

Review his wiring and using that as your basis. Nicely laid out schematic, list of components, wire, then go to work! Don't deviate until everything is completed and done.

I have to admit I love doing the design work, but these days just takes me too long to remember my drop down menu's on various CAD programs so I'll use Orton's Schematic. I'm curious what CAD program was used.

http://www.ortontransit.info/electric.php

 

[TomW]

While you could unplug everything, I like having a switch to turn off the power as needed.

At night I don't like LEDS or lights on all over the place, so a switch to turn off things is handy.

One panel, with a cigarette lighter and dual usb with a switch:
https://www.bluesea.com/products/43...cuit_Breaker_12V_Socket_2.1A_Dual_USB_Charger

They have variations of those and you can make them cheaper, but for form/function I like those little panels.

 

[TomW]

@markley

Thank you the photos of the fridge set up.

One thing about fans, when off they block about 50% of the air flow when they are not running. You might want to try some testing without a fan in the floor vent. That roof opening is enormous by comparison. I plan on having a "blast gate" to close off the floor vent when driving, otherwise open when parked.

 

[TomW]

Alison,

Could you do a sketch? I'm having a hard time following, but more due to my lack of sleep.

jpg attached from the manual
https://www.autoelec.com.au/assets/brochures/D250SA-manual-UK-EN.pdf

 

[TomW]

@Alison that looks fine.

 

[TomW]

I would probably go with a breaker between the CCP and battery switch..or have the fuse easily accessible to be able to change if needed.

Good point

In that case, to simplify, something like a BlueSea 7035 - 25 Amp Circuit breaker/switch should work. Two styles are available.

https://www.bluesea.com/products/7035/187-Series_Circuit_Breaker_-_Panel_Mount_25A
https://www.bluesea.com/products/7135/187-Series_Circuit_Breaker_-_Surface_Mount_25A

 

[TomW]

Do you think that will work, or is the 187-series you linked better for this application?

Link to Bluesea's web page
https://www.bluesea.com/products/7220/A-Series_Black_Toggle_Circuit_Breaker_-_Single_Pole_30A

That style should be fine.

If you have high inrush load (fans, fridge, etc.) the 187 series is less likely to have a nuisance trip when those items are first turned on.

 

[TomW]

@Alison you were asking where to connect the ground stud.


After tearing apart (kinda kidding) that GP25 is a tiny stud. Crud.


There is a big 8mm (?) studdon the beefy handback to the seat pedistal that would be fine.


I removed the T45 seat stop bolts (front of the seat, hidden under a simple plastic clip.
Slid the seat all way forward, and removed the metal bracked (two 8mm headed bolts under the carpet flap).


This allowed me to remove the top plastic piece over the batteries, exposing rear fuse box and the battery cable. I'd probably just use the CCP point and add a heavy wire (depending on amperange needs) to the location I circle in yellow.



When I went camping I needed only 15 Amp of power, hence my 2018 CCP COnnection used one CCP terminal and the lower stud for a ground point.

 

[TomW]

Most impressed with the "vintage" look of you ratchet wrench.

My shop needs better ventilation. That Snap On Rachet is something I cherish from my Dad. I think he bought it in 1938! Still in use, just needs to be used daily!


Oh, Dad enlisted in 1941. He was the "old man" at age 25.

Just an FYI, she has a single battery which won't look like your pic.

Darn, hopefully same battery connectors showing the studs to attach to.

 

[TomW]

@tom - I was surprised how small it was when I found it as well. My negative bus bar is pretty close though (about 1ft) on the passenger side - think it would be alright if I add a washer?

Just make a cable with proper crimped ends to go from the battery terminal to your buss bar.


Don't add a washer.