TS254 Fuse wire & Glow plugs

[sjb]

Hi,
I have a Kama TS254C and lately it has started blowing a fuse when I try to use the glow plugs. This tractor uses the same engine (Y385) as the Jinma 254.

The fuse that blows is the first one on the right. I assume that it is a main system fuse, as nothing works after it pops.
The fuses in my tractor are actually holders with a wire wrapped between 2 pins. There is extra wire wrapped around the body, to replace the used section when the fuse blows. This wire is approx 0.015" dia. which would be 26 guage wire. Does anyone know if I can use any 26 gauge wire in this fuse, or if there is something "magic" about the wire. I have used up most of the wire on this fuse.

Trying to track down the source of this problem, I checked the resistance of the 3 glow plugs. One is approximately 24 ohms, the other 2 are approx 0.9 ohms. Does anyone know what a good glow plug should read?

Thanks,
Stan

 

[greg_g]

Wire gauge is not the determining factor for fusing, it's resistance per foot that determines how much it will carry before it melts. Different metals present differing amounts of resistance to electrical current. There's a dealer/member here that goes by ARTRAC or Chip. He and I get replacement fuse wire from England. You can buy 5, 15, and 30A fuse wire (on cards) from him as your OE fuse wire supply dwindles.

I'd like to help you out myself, but I see that I'm down to one spare card

But let's address the issue of blowing the system fuse. That suggests a short in the glow plug circuit. It could be in several places; ignition switch, primary wire, glow plug buss, or one of the glow plugs themselves. The 24 ohm glow plug should be your first clue.

I'd disconnect that from the circuit, and start the tractor on two glow plugs. Don't worry, the two firing cylinders will force the 3rd one into firing with 20 seconds or so. If you haven't blown your system fuse by then, replace the suspect glow plug.

Be very observant removing the glow plug(s), the tiny little copper sealing washers have a tendency to stay in the cylinder head. Make sure they're all accounted for - one washer per plug - when you put things back together.

//greg//

 

[Affordable]

I have several of the chinese fuses like what you have,we are also a source for Jinma parts,if you need anything else.You can contact Jerry at the Shop 979-865-4002 or PM me

Tommy
Affordable Tractor Sales

 

[sjb]

Greg,
Thank you for the information.
With the copper strip disconnected from all 3 glow plugs, I do not blow the fuse, so I think that the wiring is OK.
With my short supply of fuse wire, I am a little reluctant to try connecting the glow coils one at a time.
I probably won't get a chance to try this until this weekend, but what I am planning on doing is to connect an ammeter between the battery + and each glow plug one at a time to check the current draw.
This tractor has always pulled around 30 amps when the glow plugs are first turned on, so I am assuming that a good glow plug will draw 10A or less.

 

[MrFixit]

Resistance per foot is not the only factor to consider when determining what size fuse wire is appropriate. The melting point of the metallic material is a major factor. Lead based wire of the same resistance value will melt (open Up) long before Steel wire of the same length and resistance value.

The .9 Ohm reading of the Glow Plug means each Glow Plug will draw 13.33 Amps at 12Volts DC. With 3 Plugs the total would be near 40 Amps, but probably more considering Battery voltage is generally above 12 VDC.

Assuming your Volt Meter is accurate, I suspect all 3 Glow Plugs need replacing. Two plugs seem to be drawing too much current and the Third may not draw enough.

My KAMA 354C does not have Glow Plugs so I can't do a comparison. I'm just basing this on my Rusty knowledge of Ohms law, that's if I even remember it correctly.

Tim

 

[mark1]

I also have cards of fuse wire if anyone needs them. each size has about 12-15 inches of each size wire
1 card has 5 amp,10 amp and 15 amp wire
or a card with
5 amp, 15 amp and 30 amp
I have lots of them.
2 bucks a card,,includes mailing
m.wilson
mwilson8@rochester.rr.com

 

[Keoke]

SJB, the two plugs @.9 ohms each=.45 ohms in parallel, the two 24 ohm plugs = 12 ohms, .45 ohms + 12 ohms equal 12.45 ohms total R.
So, 12.6v/12.45 = 1.01 amps total draw. So, as you can see, something is wrong with these ohmmeter readings here. The .9 readings look closer to being correct then the 24 ohm readings. The fact that you keep blowing fuses indicates that current readings are much higher then shown above.
Note, the ohmeter readings are across a cold plug, when current flows and the plugs heat up the resistance will go up a lot and the current flow will go down a lot as well.
Static battery voltage is about 12.6v but when the glow plugs and starter are running that voltage will drop to about 10.2v or so.
So, turning the glow plugs on before hitting the starter (12.6v) will run more current through them and makes blowing the fuse more probable, through not right.
Fuse wire is also used on cars but here they are called fuseible links. They come in different amps and configurations. These links are insulated with a special compound that will not burn up but will blister when blown.

good luck,

 

[MrFixit]

Hi Keoke,

I don't think this is the correct formula for total resistance for a parallel circuit:

"SJB, the two plugs @.9 ohms each=.45 ohms in parallel, the two 24 ohm plugs = 12 ohms, .45 ohms + 12 ohms equal 12.45 ohms total R."

Tim

 

[BobRip]

Hi,
I have a Kama TS254C and lately it has started blowing a fuse when I try to use the glow plugs. This tractor uses the same engine (Y385) as the Jinma 254.

The fuse that blows is the first one on the right. I assume that it is a main system fuse, as nothing works after it pops.
The fuses in my tractor are actually holders with a wire wrapped between 2 pins. There is extra wire wrapped around the body, to replace the used section when the fuse blows. This wire is approx 0.015" dia. which would be 26 guage wire. Does anyone know if I can use any 26 gauge wire in this fuse, or if there is something "magic" about the wire. I have used up most of the wire on this fuse.

Trying to track down the source of this problem, I checked the resistance of the 3 glow plugs. One is approximately 24 ohms, the other 2 are approx 0.9 ohms. Does anyone know what a good glow plug should read?

Thanks,
Stan

I suspect that the 0.9 Ohm glow plugs are OK. They are 0.9 Ohms when cold, but as they heat up the resistance will increase. Light bulbs increase their resistance by a factor of 10. I don't know what glow plugs will do, but they will increase. With a resistance of a little over one Ohms, you would pull about 30 amps. The total load resistance would be 0.33 Ohms (1/(1+1+1)). There is also some loss in the wiring and at 30 amps it is significant. Just to hazard a guess (I hate doing that) I would say you have a glow plug that drops in resistance as it gets hot. My guess is the 24 Ohm one because it is the odd ball, but that is a guess on a guess. Your solution of testing one at a time is good. Leave it on the same times as you do when starting and see what the current does. If it goes down with time it's OK, if it goes up it is shorting and should be replaced. I hope this helps.

 

[gemini5362]

I agree with bob rip that the 24 ohm glow plug is kind of suspect since it is different. In another thread some one is having a lot of glow plug problems and one of the posters said that glow plug usually have about 1.0 ohmd per glow plug. The one that reads 24 ohms if it was opening up would not blow the fuse. One poster recommended leaving it unwired and then seeing if your fuse blew while you turned power on to the other two. As far as the fuse wire goes several people have those it seems. If it was me I would just go down to the local auto store and get some of the fuse holders that take the same type fuses that go in modern automobiles. I bought a block of those kind and replaced the glass fuses in my motorcycle when I started haveing contract problems with the fuses. If you can do that then all you have to do is go to any auto parts store to get new fuses.