amperage for starters

[Soundguy]

yep.. the shorter and the fatter they are.. the less power they will disipate as waste.

soundguy

 

[Reg]

Seems like maybe I'm the only one here to have ever had a solenoid stick ?
Maybe the only one to have figured out that was what had happened ?
It is MUCH more likely to happen with a stalled starter, basically the contacts weld shut.

 

[Soundguy]

It's more likely to happen when you have slightly low voltage. low voltage = HIGHER current...

Soundguy

 

[Creekman]

What's with the attitude? And since you already have a Chinese tractor (with two batteries in the compartment), it's now curious why you thought it necessary to ask " How big of a battery do you think lalespirit can cram into a KAMA TS354?? ".

I'm beginning to smell an agitator behind your posts.

//greg//

I already told you I mis-typed 354 for 254. Obviously you grabbed on to this to make a non-existant point. If the battery case is supposed to be the same in his KAMA 254 as is in my KAMA 354 you are WRONG again, since you are talking about a single 12V battery case in his KAMA 254. Remember that you were the one who jumped into this forum with Ohm's Law, which doesn't have a whole lot to do with his original post. I had to ask him why he needed to know this bit of information twice before he answered that he was "curious". His "curiosity" has caused many other members to join in with their interpretations about "Ohm's Law", which has resulted in many inane posts. Give it a break greg, you've been had by lakespirit and I smell agitation by the both of you.

 

[Creekman]

Seems like maybe I'm the only one here to have ever had a solenoid stick ?
Maybe the only one to have figured out that was what had happened ?
It is MUCH more likely to happen with a stalled starter, basically the contacts weld shut.

Yep, it is quite likely that you are the only one out of thousands or millions of tractor or auto owners that had his solenoid stuck.

 

[SPYDERLK]

Seems like maybe I'm the only one here to have ever had a solenoid stick ?
Maybe the only one to have figured out that was what had happened ?
It is MUCH more likely to happen with a stalled starter, basically the contacts weld shut.

I would grab a pair of dikes in a case like that. It would do them any good but it would save your battery!
I have had a solenoid stick tho, and it is a solenoid issue not starter. A solenoid switching to a stationary [momentarily stalled] starter is a reasonably close analogy to switching the battery into a short circuit. Currents go high almost instantly. Inductance delays it , but starter inductance is low. The peak current seen is definitely in the ship welding range. But its only a 12V potential so the arc cant spark over the rapidly closing gap until the gap is tiny. So the time that the spark has to cause a weld is extremely, microseconds, short. Solenoids are designed to make the contact as instant as possible to prevent the welding you describe. When the contacts degrade, or other problems develop with the solenoid, such as contact bounce, that is when the contacts start welding. The starter solenoid is made for what its doing. They very seldom stick - and never a non defective new one.
larry

 

[Creekman]

yep.. the shorter and the fatter they are.. the less power they will disipate as waste.

soundguy

The larger starter cables can handle more amperage. Not a matter of waste, it's amperage. Compare the starter cables on a 6 volt system to the starter cables on a 12 volt system. The larger cables on a six volt system will handle the amperage draw if the six volt battery is replaced with a 12 volt battery. If you replace a 12 volt battery in a tractor that has a 12 volt ststem with a 6 volt battery, the amperage draw can melt the the smaller cable.
In this case "Ohm's Law" does apply.

 

[Soundguy]

Pull your slide rule out of the pocket protector and plug this in.

the shorter and fatter a conductor you have.. the better it is. if you have undersized cables not able to handle the electrical load, they will heat up and the resistance will be higher.. they will be a bottleneck in the system... That heat is a WASTE product.. and those thin cables become low value power resistors or shunts disipating lots of wattage as heat, instead of passing it near losslessly to the starter for use.

6v 1/0 thick cables are fine on 12v system.. 4ga 12v cables are NOT fine on 6v systems.

electrical power disipated as heat in this case is a waste/waste product.

This is first year high school electronics 101 stuff here... not rocket science..

soundguy

The larger starter cables can handle more amperage. Not a matter of waste, it's amperage. Compare the starter cables on a 6 volt system to the starter cables on a 12 volt system. The larger cables on a six volt system will handle the amperage draw if the six volt battery is replaced with a 12 volt battery. If you replace a 12 volt battery in a tractor that has a 12 volt ststem with a 6 volt battery, the amperage draw can melt the the smaller cable.
In this case "Ohm's Law" does apply.

 

[Creekman]

Pull your slide rule out of the pocket protector and plug this in.

the shorter and fatter a conductor you have.. the better it is. if you have undersized cables not able to handle the electrical load, they will heat up and the resistance will be higher.. they will be a bottleneck in the system... That heat is a WASTE product.. and those thin cables become low value power resistors or shunts disipating lots of wattage as heat, instead of passing it near losslessly to the starter for use.

6v 1/0 thick cables are fine on 12v system.. 4ga 12v cables are NOT fine on 6v systems.

electrical power disipated as heat in this case is a waste/waste product.

This is first year high school electronics 101 stuff here... not rocket science..

soundguy

Isn't that exactly what I said? A larger cable can handle more amperage than a smaller cable. In the tractor\auto\heavy equipment world the length of the batery cable is determined by the manufacturer and the cable is sized accordingly. Why do you disagree?
Is losslessly really a word?

 

[greg_g]

Isn't that exactly what I said? A larger cable can handle more amperage than a smaller cable. In the tractor\auto\heavy equipment world the length of the batery cable is determined by the manufacturer and the cable is sized accordingly. Why do you disagree?
Is losslessly really a word?

Losslessly is an adverb Dave (from the adjective lossless) borrowed from the audio engineering world. Even so, I suspect I am in a majority that had no trouble understanding how it was used in that sentence. But to keep this professional, the "Why do you disagree" question is probably best left unaddressed.

In anybody's world, the length of a battery cable is determined by the distance between the two points it connects. We're talking gauge (diameter) here. The gauge selected is electrically dictated by the composition of the wire, the diameter of the cable, and the length of the run. No one's arguing that "larger" cable can't handle more amperage than a "smaller" cable. So sticking to diameter, Chris merely tried to explained to you WHY gauge must increase in proportion to load and length. Heat loss. BE&E 101.

Let's assume for a second that you've never heard of a fuse. It's typically a piece of intentionally undersized wire that is placed in series with an electrical circuit for the express purpose of self-sacrifice in the event of an amperage overload. What blows a fuse? Heat. The diameter of the fuse wire is insufficient to support any amperage that could otherwise be sufficient to damage the equipment it's been inserted to protect.

//greg//