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Wareagle1970
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409 Posts
Discussion Starter #1
Okay, found some of this wiring harness loom tubing at Lowes. Their site didn't have the temperature specs so I called the company. The mentioned that the high temperature is 200 degrees F.

Would this be okay for wrapping the wiring harness from the stator wires to right behind the battery box?

The link to the product is
https://images.tradeservice.com/OMHPCVA38H2GOHK7/ATTACHMENTS/DIR100012/IDELINE00164_D7.pdf

search for 772241

Thank you in advance,
Steven
 

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Linkmeister Supreme
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7,960 Posts
Okay, found some of this wiring harness loom tubing at Lowes. Their site didn't have the temperature specs so I called the company. The mentioned that the high temperature is 200 degrees F.

Would this be okay for wrapping the wiring harness from the stator wires to right behind the battery box?

The link to the product is
https://images.tradeservice.com/OMHPCVA38H2GOHK7/ATTACHMENTS/DIR100012/IDELINE00164_D7.pdf

search for 772241

Thank you in advance,
Steven
As long as the plastic loom doesn`t touch the exhaust pipe or the goat`s belly, it should be fine. :smiley_th
 

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Wareagle1970
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409 Posts
Discussion Starter #3
Thanks Gordon. Picked up some from Lowe's tonight.
 

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Premium Member
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117 Posts
More important than the temp rating of the loom is the temp rating of the wire insulation. I gather from your other posts that you have rewired the stator / regulator wiring. What is the rating of the wire insulation? The current carrying capacity rating of any particular guage is primarily dependent in it's insulation temp rating (and allowable voltage drop). The same wire will have a higher current rating in "free air" than if it is bundled in or in a conduit.

Our charging system is rated at 24 A @ 14 VDC. Assuming equal current distribution among the 3 AC stator phases, that give you 8 A(RMS) per wire.

Bundling the wires in a loom will reduce the current rating of the wires unless you use a higher temp insulation for a given wire size.

Bottom line: the loom may be just fine, but may cause your wires to overheat depending on wire guage and insulation temp rating.
 

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Linkmeister Supreme
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More important than the temp rating of the loom is the temp rating of the wire insulation. I gather from your other posts that you have rewired the stator / regulator wiring. What is the rating of the wire insulation? The current carrying capacity rating of any particular guage is primarily dependent in it's insulation temp rating (and allowable voltage drop). The same wire will have a higher current rating in "free air" than if it is bundled in or in a conduit.

Our charging system is rated at 24 A @ 14 VDC. Assuming equal current distribution among the 3 AC stator phases, that give you 8 A(RMS) per wire.

Bundling the wires in a loom will reduce the current rating of the wires unless you use a higher temp insulation for a given wire size.

Bottom line: the loom may be just fine, but may cause your wires to overheat depending on wire guage and insulation temp rating
.
I should have remembered that sunpa.

I recall now, someone saying a long time ago that tying the stator wires together on his bike, was the cause of overheating them and burning one or two of the connectors off.
 

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Wareagle1970
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409 Posts
Discussion Starter #6
Thanks again for the input Sunpa. I need to check the insulation of the new 14 gauge wires I replaced the existing stator wires with. Will definitely individually wrap each stator wire with good electrical tape to avoid them passing heat to each other. Will most likely wrap them from the stator all the way to the R/R, just for an extra measure. Now, would I need to also rewrap the section of the wiring harness that I removed the previous wrapping with when I rewired the stator wires, or would the conduit work fine?
 

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Just throwing this out there..I noticed when repairing my stator wires the previous owner had actually run the stator wires through a piece of conduit..put a few slight bends in it and uzed zip ties to secure it to the frame and believe it or not it looks good (its painted black so blends in) lol
 

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Wareagle1970
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409 Posts
Discussion Starter #8
Just throwing this out there..I noticed when repairing my stator wires the previous owner had actually run the stator wires through a piece of conduit..put a few slight bends in it and uzed zip ties to secure it to the frame and believe it or not it looks good (its painted black so blends in) lol
Dang, I wish I would have thought of that before I removed the wiring harness insulation. I wonder, though, with just the stator wires running through the conduit, isn't it still possible they would produce enough heat to melt them together (if they were touching in the conduit that is).
 

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Wareagle1970
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409 Posts
Discussion Starter #10
I gotta say the copper does look pretty cool.
And I like the fact that it keeps the stator wires away from the wiring harness.
 

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More important than the temp rating of the loom is the temp rating of the wire insulation. I gather from your other posts that you have rewired the stator / regulator wiring. What is the rating of the wire insulation? The current carrying capacity rating of any particular guage is primarily dependent in it's insulation temp rating (and allowable voltage drop). The same wire will have a higher current rating in "free air" than if it is bundled in or in a conduit.

Our charging system is rated at 24 A @ 14 VDC. Assuming equal current distribution among the 3 AC stator phases, that give you 8 A(RMS) per wire.
Bundling the wires in a loom will reduce the current rating of the wires unless you use a higher temp insulation for a given wire size.

Bottom line: the loom may be just fine, but may cause your wires to overheat depending on wire guage and insulation temp rating.
I do not believe this is correct.... a mutiphase AC generator's current depends on the phasing angle...... It's not as simple as 24/3.
 

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I should have remembered that sunpa.

I recall now, someone saying a long time ago that tying the stator wires together on his bike, was the cause of overheating them and burning one or two of the connectors off.
I would find this hard to believe.... If the wiring is sized properly for the load, tying three wires together shouldn't make things melt. I bet the real cause was something else....
 

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Wareagle1970
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409 Posts
Discussion Starter #15
Okay, so here is my plan and please let me know if anyone sees a potential issue.

I will have 2 lengths of the conduit, 1 will contain the stator wires by themselves, while the other will contain the rest of the wiring harness.

Any issues anybody can think of?
 

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Premium Member
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I do not believe this is correct.... a mutiphase AC generator's current depends on the phasing angle...... It's not as simple as 24/3.
POWER, not current, (either single of multiphase) is dependent on current phasing with regard to voltage. If rated current of 24 ADC is leaving the R/R to the battery & loads than 24 A(RMS) will be entering the R/R from the stator wires before rectification. Eight Amps per wire may not be precise though in that there may be unbalance and small capacitive leakage in the wires, but the load is primarily resistive. There may also be some "shunt regulation" current within the R/R, but it should be small at rated conditions. For estimating purposes 8A per wire is probably close enough. (Note that this is max rating at 8000 RPM (I think) so the wiring will rarely see this current for any extended period.)

I would find this hard to believe.... If the wiring is sized properly for the load, tying three wires together shouldn't make things melt. I bet the real cause was something else....
I agree. The "something else" is if heat is generated due to high resistance caused by poor connections / corrosion then bundling the wires can trap the heat and melt the insulation. By the way, I believe the wiring on our bikes is marginally sized with little excess capacity to handle extra loads, dead (shorted?) battery, or faulty connectors. If the electrical system is properly maintained there should be no problem.

Okay, so here is my plan and please let me know if anyone sees a potential issue.

I will have 2 lengths of the conduit, 1 will contain the stator wires by themselves, while the other will contain the rest of the wiring harness.

Any issues anybody can think of?
Should be OK, especially since you rewired with a larger guage stator wires.
 

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Okay, so here is my plan and please let me know if anyone sees a potential issue.

I will have 2 lengths of the conduit, 1 will contain the stator wires by themselves, while the other will contain the rest of the wiring harness.

Any issues anybody can think of?
Make sure the wires are protected where there enter the conduit with a grommet or something. If the wires are rubbing against a hard edge, vibration will cause the insulation to wear through.
 

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Wareagle1970
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Discussion Starter #18
Make sure the wires are protected where there enter the conduit with a grommet or something. If the wires are rubbing against a hard edge, vibration will cause the insulation to wear through.
Very good point and one I didn't consider. Thank you for your input Sunpa.
 

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POWER, not current, (either single of multiphase) is dependent on current phasing with regard to voltage.
Don't really know what you are getting at here......


If rated current of 24 ADC is leaving the R/R to the battery & loads than 24 A(RMS) will be entering the R/R from the stator wires before rectification.
I don't believe so. The current entering the R/R should be much less.
Here is the way I see it, so please tell me where I'm going wrong:
Thermodynamics dictates power in must equal power out...... so our energy balance would look like this: Stator Watts input to R/R = output from R/R + heat losses, shunt, R/R power factor, ...
If we assume max output of 24 Amps @ 14VDC then we can eliminate the power losses due to the shunt. In other words, if we are using all the power available none will be sent to ground. Therefore, we are left with power from the stator = power output of R/R. (let's assume the R/R power factor is a non-issue as well other small losses due to wire resistance and such)
So, if the max output is 24A @ 14VDC that's 336 Watts. Now we know the stator puts out around 70 VAC max, 3-phase. (the max R/R output condition)
Hence, 336 Watts/(70VAC*sqrt(3)) = 2.77 Amps.....
Of course, it will be slightly higher due to the R/R power factor....
[/QUOTE]
 

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Interesting stuff! This detail may seem off-topic, but is related in that we are trying to estimate the stator wiring current which of course relates to voltage losses and wiring temperature rise. dariv - Thanks for questioning my initial estimate - I had to shake out the cobwebs.

Don't really know what you are getting at here......
I did not state it very well, but my earlier comment meant that the Magnitude of the Current produced by either a single of multiphase alternator is not dependent on phase angle with regard to voltage - Power is.

I don't believe so. The current entering the R/R should be much less.
Here is the way I see it, so please tell me where I'm going wrong:
Thermodynamics dictates power in must equal power out...... so our energy balance would look like this: Stator Watts input to R/R = output from R/R + heat losses, shunt, R/R power factor, ...
If we assume max output of 24 Amps @ 14VDC then we can eliminate the power losses due to the shunt. In other words, if we are using all the power available none will be sent to ground. Therefore, we are left with power from the stator = power output of R/R. (let's assume the R/R power factor is a non-issue as well other small losses due to wire resistance and such)
So, if the max output is 24A @ 14VDC that's 336 Watts. Now we know the stator puts out around 70 VAC max, 3-phase. (the max R/R output condition)
Hence, 336 Watts/(70VAC*sqrt(3)) = 2.77 Amps.....
Of course, it will be slightly higher due to the R/R power factor....
[/QUOTE]

Good analysis. My initial estimate of current (24A / 3) was based on simple current balance in the R/R. Your Power balance method is another approach that I hadn't thought of. I agree with your assumptions with the exception of the 70 VAC stator voltage. I am certainly not an expert in this area, but here is my thinking.

Current delivered by the stator causes a back emf in the windings that reduces it's output voltage. This is how the shunt regulator controls voltage - by drawing current that "bypasses" the rectifier stage. I think of the R/R as two boxes, an upstream shunt regulator and a 3-phase diode bridge rectifier. The DC output Voltage of the rectifier is somewhere between the input RMS and Peak AC Voltage input. (I believe this is true - I don't know the conversion calculation. Also the stator output is probably not a pure sine wave form.)
So, I'm thinking that in order to regulate the DC voltage to 14-15 volts the AC side must be somewhere around 16 - 20 VAC. (The 70VAC that you assumed I believe was based on our stator open circuit test which says it should be 50-70VAC. BTW this test is not specified in the Service Manual or Clymers) By using 20 VAC instead of 70 VAC in your power calculation the result is 9.7 A.

As you assumed, at rated conditions there should be little to no shunt current. If the load decreases the shunt regulator draws current to keep VDC between 14-15 volts. So at any given engine speed the stator wires see about the same currrent regardless of DC load. My guess is that the stator output at 4000 rpm is something like 80% of rated which is specified at 8000 rpm. So I'm estimating that the stator wires carry something between 7 and 10 amperes during normal riding. (Assuming that the load does not exceed the charging system capacity and results in low DC voltage.)


The OEM stator wires appear to be about 18 guage? (or 1 sq mm metric wiring) Resistance is about 20 mOHM per meter. Assuming 1 meter? from stator to R/R and 10 A per wire the power loss (discounting connector resistance) would be ~ 2 W. This "feels" about right - the wires do get quite warm.

Anyway, this is my thought process. Let me know if I'm off-base - I've been there before.
 
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