What have you done to your 5 ton this week?

[TechnoWeenie]

Just looked up a Delco Remy 42MT, which is replacement starter for NHC250....800A @24V


http://www.newindo.com/delcoremy/42mt-delcoremy-startermotor.htm

 

[TechnoWeenie]

The OEM military slave cables are 2/0. The slave plugs are rated 500 amps. And yes, they all heat up. The TM gives instructions of so many 15 second cranks, then you have to let them cool.

My primary welding leads are 2/0. Stick welding at 140 amps doesn't get them warm, welding as fast as you can change rods.


Edit - the starter pulling 500amps strikes me as correct.

My custom made cables are ~30ft....Which increases resistive loss...

Typical military battery set up is 4 batteries 12v 550cranking amps, connected in series and parallel. That gives 1100 cold cranking amps at 24v.

Not quite. 5 tons use 6TL/6TMF

In series and parrallel, that gives you 2x the voltage, and 2x the amperage = 24V, and considering......


6TL=

SPECIFICATIONS:
12 Volts
Flooded Lead Acid Low Maintenance
Length : 10-1/2”
Width : 11-7/8”
Height over terminals: 9”
CCA & Capacity:
CCA @ 0F = 825 CCA
CA @ 32 F = 1010 CA
215 Mins RC @ 25 Amps


That would mean 24V and 2020 CA or 1650 CCA...

NOT 550 CCA x 2 = 1100

 

[Mos68x]

My CAT Dozer draws 60 amps on a long crank with 2/0 cables
I cannot get a reading on the 8.3 as it fires right up as soon as the starter engages. Apparently the high/low setting on meter is not working.
If you are drawing enough to worry about burning out a switch you need to look at your starting system. I have seen a 2/0 cable so bad that you could touch the opposite post of a battery with it and not get

You can always engage the emergency engine stop to get a reading.

 

[Jakelc15]

The starter will draw the most amps to get moving. Once cranking it will hold a steady amp draw under 150.
As posted above the 42mt draws 800 amps max. They rate these starters by torque @ volts @ amps @ rpm. If the starter draws more than the 800a spec, you have another problem and it probably won't be spinning fast enough to start the truck.
We shouldn't be adding variables to this, we should be out enjoying and or working on our trucks.

I think a battery cutout should be on everyones to do list. It not only helps to prevent theft but it seems to slow corrosion on electrical items. Also as a side note, anyone that lives in the Salt belt, I have found that the red battery protector spray works very well. I use it on all connections and makes mating the packard connectors easier.

 

[TechnoWeenie]

The starter will draw the most amps to get moving. Once cranking it will hold a steady amp draw under 150.

What do you think 6+ gallons of 15w40 does in cold temperatures that could impact the starter in terms of ability to turn vis a vis amp draw?

You cannot plan everything for best condition scenarios....

We shouldn't be adding variables to this, we should be out enjoying and or working on our trucks.

Safety first. As an emergency vehicle upfitter (installing lights/sirens/computers/communication,etc), and having to fix other people' screwups, I can tell you vehicles DO catch fire because of poor wiring and substandard equipment...Most of the time it's fairly minor, but I have seen vehicles go up in flames, $15k in equipment and $25k vehicle, complete loss, because of an innocent mistake (officer tried to wire in new equipt by himself).

The biggest part of this hobby/community, IMO, is the sharing of knowledge, that includes having the cajones to step up to someone and say 'uhhh, hey, that doesn't look right, you might wanna reevaluate that'... Ultimately, it's their rig, but knowing what I know, I wouldn't suggest one like that, it took me a couple DAYS to finally decide on the proper cutoff switch... Just saying... And if a guy who was an expert on the *insert system here* and tells me my modification of *system* needs to be double checked, and shows why, I'd definitely double check it, even if I thought I was still right.

Batteries are one of those things YOU DO NOT WANT TO BE WRONG ON......Shorted batteries, melted contacts, etc...

and about the cutoff, you do realize you're supposed to switch the ground right, and not the positive? If the switch is damaged or fails, or a wire comes loose, and contacts metal, no harm no foul. If the + wire contacts grounded metal, you can explode the battery...

 

[Jbulach]

The starter will draw the most amps to get moving. Once cranking it will hold a steady amp draw under 150.
As posted above the 42mt draws 800 amps max. They rate these starters by torque @ volts @ amps @ rpm. If the starter draws more than the 800a spec, you have another problem and it probably won't be spinning fast enough to start the truck.
We shouldn't be adding variables to this, we should be out enjoying and or working on our trucks.

I think a battery cutout should be on everyones to do list. It not only helps to prevent theft but it seems to slow corrosion on electrical items. Also as a side note, anyone that lives in the Salt belt, I have found that the red battery protector spray works very well. I use it on all connections and makes mating the packard connectors easier.

There should be someone around here that knows a little bit about HOW MANY AMPS...

That is a very common marine battery bank switch, made by Perko.

On a stock mil alternator, be sure not to switch the batteries off while the engine is running. The alternator will lose its reference voltage, and go to full voltage output. Usually wipes out PCB, ABS, and CTIS modules. Any civilian alternator upgrade is protected against this.

Maybe he's busy sitting in his lazy boy with a plunger stuck to the floor watch how to shift video's?

 

[Jakelc15]

Maybe he's busy sitting in his lazy boy with a plunger stuck to the floor watch how to shift video's?

Haha, thats suppose to happen this month! I hope he does get started on it soon, I would like to do just about the same thing.

 

[Mos68x]

I finally got my truck stuck Friday night

 

[Mos68x]

It took the help of a local 925A0 to get it out


https://youtu.be/L2Mum8KuxMs

 

[74M35A2]

It's more fun to sit back and watch the sh!t fly from one side of the room to the other.

ISL/13 speed combo is progressing. Summer cruises are over now. Getting kids kicked off to new schools, then I can rip the utereus out of my 9 for the transplant.

Love the plunger comment, that will be stuck in my mind permanently now. Good job.

 

[74M35A2]

Jbulach has too many amps, so don't ask him. He's my bro on this exact topic.

Our 24v starters pull 900 amps initial inrush, and 450 amps average during cranking an 8.3L which is already warmed. For a 250 engine, these figures will be higher. LDT/S, same as 8.3L. Cold oil will he higher, as mentioned.

Most plastic marine battery switches such as pictured above are for gasoline engine use. Their current rating is time based. They can handle more in short events, and especially inrush. Most of them even include the time based chart with them or on their website. Like everything else, there is margin in there too for CYA on their behalf.

We size original application battery cables based on resistance only. This is on a milli-ohm scale. Example would be 2 mOhm total circuit reaistance (positive and negative cables combined). This way it accounts for diameter and length, both. Larger diameter cable has lower resistance. You don't need to size starter cables based on the same continuous current rating of Romex wire in a house. The stock cables on my M925a2 are large enough diameter to be used on a 12v system of double the current.

I don't know of any applications that disco the ground on a battery switch. All I have seen do it via the positive. These include the latest 2017 Kenworth trucks.

 

[TechnoWeenie]

I don't know of any applications that disco the ground on a battery switch. All I have seen do it via the positive. These include the latest 2017 Kenworth trucks.

Just because 'it's always been done that way' doesn't make it right...

When everything is working as it should, it really doesn't matter..

But again, see what I said earlier about not planning for perfect conditions..

A loose terminal from vibration, manufacturers defect causes connection to come lose, wear causes slivers of metal to come off, etc..

Any way you look at it, having a positive terminal, half an inch from a negative grounding point is not the smartest thing to do..

Now, contrast that to a negative cable being attached, and it fails and contacts the metal of the mount.... You'll get a small spark and a *click* when the small contact point can't carry that much current to start the vehicle...

I can tell you which one will do less damage....

 

[74M35A2]

I respect tangent ideas. Seriously, I have seen a lot of things accomplished that way.

 

[Jakelc15]

All Caterpillar equipment disconnects the ground side of the batteries. Marine application seems to be the opposite. I put mine on the ground. Proper installation is the key. A poor connection at the disconnect is no different than a poor connection at the starter.

 

[Swamp Donkey]

Just put a disconnect on each of POS and NEG cables and move on. Redundancy at its finest...

 

[74M35A2]

Just put a disconnect on each of POS and NEG cables and move on. Redundancy at its finest...

Hero status just awarded to SD !!!

 

[farmerboywyotech]

So had a busy weekend though not as productive as i hoped. Finally got a solid start in my dump conversion on my m925. Had a plan but its been alot of engineer as i go. Also finally fixed up the band saw only been planning to do it for the better part of a decade. Im debating on starting a thread on it. Might be an educational experience worth sharing.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[gimpyrobb]

Hero status just awarded to SD !!!

You mean SRD?

 

[Jbulach]

... Im debating on starting a thread on it. Might be an educational experience worth sharing...

YES! I would imagine just about everyone with a cargo truck would like to make it dump. The more experiences documented the better...

Truck and bandsaw both looking good!

 

[TechnoWeenie]

Just put a disconnect on each of POS and NEG cables and move on. Redundancy at its finest...

Now you're not adding any safety, just add'l points of failure...