4 Curious Georges' 2001 Saf-T-Liner

[BlackJohn]

Originally Posted by Twigg

Right. It might trip once the bus is on fire.

I'm sure the pipefitter will know, he sees this stuff all the time. feeling the insulation tells me nothing of the wire temp internally so not going to argue black is white with you.

John

[david.dgeorge07]

Originally Posted by joeblack5

That is not a very durable and reliable breaker style for your application. It is inexpensive.

These are identical in design to the main breakers that the OEM used as main breakers for the bus. It uses one for the chassis and one for the body and I manually trip them both when the bus is off for a while to eliminate parasitic drain.

Originally Posted by joeblack5

Then some like yours probably ( thermal) can handle short peak loads of 200 Amp, like in audio systems, and have a long time load of much less.

Based on an inductive amp meter, two copies of this breaker tripped after about 20 seconds at 137 amps.

Originally Posted by joeblack5

And as Black John said breakers are there to protect the wiring against overload and a fire.

I'm aware. The last thing I want is a fire, I just need to figure out how to keep power flowing when the load and wire size is appropriate to the application.

[david.dgeorge07]

Originally Posted by BlackJohn

Wire size might have everything to do with the trip. That is a sizeable load and breakers work instantaneously to protect the wiring.

John

Would the lugs be warm if this is the case?

[david.dgeorge07]

Seems like there are a few options as to what could be the problem:

1. Defective breaker. I tested two identical ones and they both behaved the same.
2. Undersized or improperly terminated cable. I will continue to explore this, but so far the lugs have not even felt warm, which seems like would be the case if there were an ampacity problem.
This is the table I used. My 12V cable run is only about 4-5 feet.
Wire Gauge Tables
3. Wrong application: a 200 amp breaker of this design really isn't meant to be loaded to 70% of its rated capacity on a 100% duty cycle?
4. Something else?

[BlackJohn]

Originally Posted by david.dgeorge07

Would the lugs be warm if this is the case?

I really have never made a practice of touching lugs, hot or otherwise.
I am sure they would have some warmth for sure but how much is beyond me.
Instead of all these experts here why not call the mfg and find out before you have a bigger problem. Talk to their engineers and find out what is what.
Not trying to be smart but it appears some know all about everything and like to argue beyond reason.
My concern is the #2awg wire which is overloaded at 138amps.

John

[joeblack5]

look do some google on breakers for DC and you will find plenty of good info.
The breaker you used is not for this application.
A thermal breaker, like yours, will trip on heat generated by the current going thru the breaker. The heat will bend a bimetallic strip and then will trip the contact. So depending on the outside temperature a higher current will trip the breaker faster then a lower current. So it is very well possible that your breaker trips at a constant current of 130 Amp ( google the spec of your breaker and you will know). At 200 amp that breaker has to trip in X amount of milliseconds.
Like I said the magnetic breakers have also a coil in them that actually "measures" the current and trip much more accurately and less dependent of temperature. Google will have your answers.

Later J

[joeblack5]

look do some google on breakers for DC and you will find plenty of good info.
The breaker you used is not for this application.
A thermal breaker, like yours, will trip on heat generated by the current going thru the breaker. The heat will bend a bimetallic strip and then will trip the contact. So depending on the outside temperature a higher current will trip the breaker faster then a lower current. So it is very well possible that your breaker trips at a constant current of 130 Amp ( google the spec of your breaker and you will know). At 200 amp that breaker has to trip in X amount of milliseconds.
Like I said the magnetic breakers have also a coil in them that actually "measures" the current and trip much more accurately and less dependent of temperature. Google will have your answers.

Later J

[david.dgeorge07]

Test fitting the indoor half of the split.


Sent from my iPhone using Tapatalk

[david.dgeorge07]

Got all this deleted. And yes, the bus still starts and all the lights work.


Sent from my iPhone using Tapatalk

[01ThomasMVP]

I would love to see a pic of your control panel! This is where I'm at as well but trying to get all the useless wires out of the control panel, and taking out all the useless switches.

Sent from my SAMSUNG-SM-G935A using Tapatalk

[Robin97396]

That pile of wire represents a lot of checking to see if the bus still runs.

I didn't go that far. I did remove any dead end wires.

[david.dgeorge07]

Backup cam arrived a day early! Glad to get it installed before buttoning up the rear bulkhead. Installation couldn’t have been easier.


Sent from my iPhone using Tapatalk

[david.dgeorge07]

Got some snow here. Still working on the rear end of this thing...


Sent from my iPhone using Tapatalk

[Robin97396]

That's looking very familiar with all that insulation and wood.

[joeblack5]

Wow, impressive. 120 vac in the back. That is lot of extra work and planning. I could not do that. I limit the 120 vac to the kitchen area for cooking etc.
The rest is all directly of 24 or 12 volt.

Are you going to fill the in between space with foam to avoid mice and insects?

later J

[david.dgeorge07]

Originally Posted by Robin97396

That's looking very familiar with all that insulation and wood.

Looks like Home? Should get to painting some eventually.


Sent from my iPhone using Tapatalk

[david.dgeorge07]

Originally Posted by joeblack5

Wow, impressive. 120 vac in the back. That is lot of extra work and planning. I could not do that. I limit the 120 vac to the kitchen area for cooking etc.
The rest is all directly of 24 or 12 volt.

Are you going to fill the in between space with foam to avoid mice and insects?

later J

I decided that I would cross the bus from driver’s side to passenger side for all power at the rear of the bus rather than going through the floor or the roof. Once I made that decision it was easy to add drops for AC power in the rear end here. I don’t know if you can tell from the photos but there’s DC wiring that terminates there which will be used for reading lights.

I hadn’t thought of filling in that space. I suppose it would be possible that varmints could get in there. I’m afraid there may be quite a few places in the bus where something might be able to get in and fit. I guess I was counting mostly on the fact that spray foam isn’t super hospitable to keep them away but maybe I need to think more seriously about sealing all cracks and voids. Do any of you have build experience on having problems with these things and or ways to make sure to mitigate to them?

At least in this case and/or area I think a few beads of caulk would likely make it difficult to impossible to enter.


Sent from my iPhone using Tapatalk

[david.dgeorge07]

Originally Posted by BlackJohn

Just do one board at a time, 4 bolts gets it free for back wire access. Cut out what you need and are sure of but you might want to do the start up for each item removed to be on the safe side. Those relay bases are tricky to come apart and get the wire out. Those wires should go the connectors up top that I see. Even to pull fuseing and relays without cutting should do the trick but I guess you want complete removal.

John

Still working on this! Thanks for the advice! Will post pics when I can.


Sent from my iPhone using Tapatalk

[Rusty]

Originally Posted by david.dgeorge07

Got all this deleted. And yes, the bus still starts and all the lights work.

Wow ! That is a birds nest.

I understand the desire for a simpler wiring, but wow. The bus manufacturer purposely ran a few extra circuits in case one fries/options. Taillight cable gets corroded, that extra wire is all run, ready to go.


I had several extra circuits that ran full-length of the bus- 2 extra grounds back to box and 4 extra circuits run to rear tail lights. I could remove them, or utilize for trailer brake controller, external LED floodlight, DC outlet, etc. It's all run properly, bundled secure and fused. Even those door alarm wires could each be used to run a little porch light LED.

Making good progress.

[david.dgeorge07]

Originally Posted by Rusty

Wow ! That is a birds nest.

I understand the desire for a simpler wiring, but wow. The bus manufacturer purposely ran a few extra circuits in case one fries/options. Taillight cable gets corroded, that extra wire is all run, ready to go.


I had several extra circuits that ran full-length of the bus- 2 extra grounds back to box and 4 extra circuits run to rear tail lights. I could remove them, or utilize for trailer brake controller, external LED floodlight, DC outlet, etc. It's all run properly, bundled secure and fused. Even those door alarm wires could each be used to run a little porch light LED.

Making good progress.

Totally hear you. That's part of the reason I pulled. As they were run the wires were bundled and dead-ended in places that were not useful. By pulling the dead ones out it made them capable of being re-run to be useful. My cable chases will be permanently accessible so I can easily add whatever needed as needed.