First Impressions - RTV X1100c

Here's a page from my WSM. It doesn't mention a relay. In the description of the process it appears as the glow plug heats it reduces the flow of current. This would be how it protects itself from burning up.

I'll study the wiring diagram and look for a relay. Those things confuse me.

I don't recall seeing a relay under the dash but wasn't really looking for one either.

Maybe it's as you say and it's the hour meter clicking. Maybe he dummied it down for me, assuming the time it would take the hour meter to click would be sufficient to accomplish it's task.

Him telling me to recycle if I think it needs more would be to allow the glow plug heat to dissipate into the combustion chamber. As that heat rises the glow plug is going to create less heat until it is doing nothing?
 

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Good discussion. The information given by Beru ()http://beru.federalmogul.com/sites/default/files/ti_04_gb_2014_fm.pdf
describes how their glow plugs and controllers are self limiting in terms of current for rapid heatup, but with protection of the glow plugs. I don't know what brand of glow plugs that Kubota uses.

"During pre-heating, a high current initially flows via the connecting
bolt and the regulating coil to the heating coil. The
latter heats up quickly, causing the heating zone to glow.
Glowing quickly expands – after 2-5 seconds, the heating rod
glows up to near the plug body. This additionally increases the
temperature of the regulating coil that has already been heated
up by the current. Then, the electrical resistance increases and
the current is reduced to a point where it cannot cause any
damage to the glow rod. Overheating of the glow plug is thus
not possible.
If the engine is not started, the glow plug will be switched off
by the glow time control unit after a certain stand-by time.
The resistance of the alloy used on BERU glow plugs increases
with the temperature. It is thus possible to design the regulating
coil in such manner that it will initially let through a higher
current to the heating coil than when it reaches the target
temperature. The target temperature is thus reached quicker
and is maintained within the permissible range by an increased
regulating effect."
 
Interesting video on testing glow plugs from Kubota 905e engine: https://video.search.yahoo.com/yhs/search?fr=yhs-iry-fullyhosted_003&hsimp=yhs-fullyhosted_003&hspart=iry&p=glow+plugs+for+kubota+D1105+diesel+engines#id=3&vid=1468d46e8f783dfb618c141bb554e9ca&action=click

The glow plugs are necessary in the Kubota 1105 engines because they are IDI (indirect injected) diesel engines. The fuel is injected into a prechamber that has relatively high heat losses, so the compression temperatures are rapidly reduced as they flow into the cold prechamber and are insufficient to light off the fuel at low ambient temperatures. IDI engines are less fuel efficient than DI (direct injected) engines, but can utilize lower pressure, much less expensive, injection systems. However, they require starting aids like glow plugs or manifold heaters, while DI engines often do not.

Lee
 
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Good stuff.

The description of the process you posted is much easier to understand than what's in the WSM. I think sometimes the translation from Japanese to English does that.

I've never tried holding my key to the Glow Plug position for a long period of time to see if it finally goes off.

My JD2210 definitely uses a relay to control it's plugs. It doesn't use a light. It definitely cranks easier if you cycle the circuit a couple times.

Good explanation of the difference between an IDI engine and a DI engine as well. :)
 
My book says "Turn the key to "preheat" position and hold it for preheating"

over 32 F 2-3 sec
23-32 F 5 sec
5-23 F 10 sec
Limit of Continuous use 30 sec
 
My book says "Turn the key to "preheat" position and hold it for preheating"

over 32 F 2-3 sec
23-32 F 5 sec
5-23 F 10 sec
Limit of Continuous use 30 sec

Good info. 30 second max must be when the glow plugs finally achieve max resistance and quit offering heat??
 
Sounds reasonable! Also book recommends block heater to "assist in starting below -4f" Also mentions warming up the transmission in cold climates to avoid hi pressure problems if anyone wants that info i can forward
 
For the heaters, I put one on my block (oil pan) and another on the transmission. I pulled the plugs up to where they sit just above the battery. I can then plug them into the wall easily. I normally use a timer as I know what time of day I'll need the RTV. The heaters make a huge difference.
 
Good stuff guys......I like the glow plug gizmo on my old Iseki. It was a small resister coil in a gauge on the dash. When it finally glowed like a toaster it indicated the engine was ready to start. Kinda cool to watch and not have to do the one thousand 5 bit...........
Don't feel bad Oversized, I had my granddaughter thinking that the click is telling you to tighten up the fuel cap...........
 
Good stuff guys......I like the glow plug gizmo on my old Iseki. It was a small resister coil in a gauge on the dash. When it finally glowed like a toaster it indicated the engine was ready to start. Kinda cool to watch and not have to do the one thousand 5 bit...........
Don't feel bad Oversized, I had my granddaughter thinking that the click is telling you to tighten up the fuel cap...........

Yeah, that's what I get for listening to the mechanic.

No worries.

I tested mine this afternoon. Turned the key to "glow", stop watched if for 90 seconds and the light never went off. Started just the same as it would have with a few seconds of "on".

So as described above, the glow plugs are only effective for a few seconds, then they stop generating heat.
 
Yeah, that's what I get for listening to the mechanic.

No worries.

I tested mine this afternoon. Turned the key to "glow", stop watched if for 90 seconds and the light never went off. Started just the same as it would have with a few seconds of "on".

So as described above, the glow plugs are only effective for a few seconds, then they stop generating heat.

It is not my understanding that the glow plugs stop generating heat as long as they are still powered, ovrszd. Rather, the glow plugs are designed to heat up rapidly with a high current flow (due to the low resistance of the cold glow plug), with gradually decreasing current as the plug heats and its resistance increases, to a final steady-state (very hot) temperature, and then to stay at that condition. If the temperature of the glow plug starts to drop, then the electrical resistance decreases, the current increases, and the temperature is re-established at the steady-state condition. The power into the glow plug is I^2 x R, where I is the current and R is the resistance. That reaches a steady-state condition when the glow plug reaches its maximum temperature, and it stays at the condition until the voltage to the glow plug is removed.

Concerning your tests, note that the manual suggests limiting the "on-time" to 30 s to improve the life of the glow plugs, but thanks for your sacrifice in the name of science!

Lee
 
Think about how your toaster works. I think that it uses nichrome wire that has a slight increasing resistance vs. temperature characteristic. The toaster wires reach a steady state temperature and stay at that temperature at constant voltage input. The heat output does not stop until the voltage is removed.
 
Ovrszd, to test you could put a analog volt meter or probably a digital multimeter on your battery and watch the voltage drop while you hold the key to the glow position. At least the voltage meter on the dash of my truck does that when I'm cycling glows
 
It is not my understanding that the glow plugs stop generating heat as long as they are still powered, ovrszd. Rather, the glow plugs are designed to heat up rapidly with a high current flow (due to the low resistance of the cold glow plug), with gradually decreasing current as the plug heats and its resistance increases, to a final steady-state (very hot) temperature, and then to stay at that condition. If the temperature of the glow plug starts to drop, then the electrical resistance decreases, the current increases, and the temperature is re-established at the steady-state condition. The power into the glow plug is I^2 x R, where I is the current and R is the resistance. That reaches a steady-state condition when the glow plug reaches its maximum temperature, and it stays at the condition until the voltage to the glow plug is removed.

Concerning your tests, note that the manual suggests limiting the "on-time" to 30 s to improve the life of the glow plugs, but thanks for your sacrifice in the name of science!

Lee

Yep. That's how I understand it as well. "Stops generating heat" isn't absolutely correct. The heat generated is lowered to a point that it won't burn out the glow plug. That level of heat probably does little to improve starting. Thus, no need to hold it on more than 30 seconds.

Pretty cool that they figured that out. Offering a fast/high heat source for those in a hurry while protecting the device from those that think they need to hold the switch on longer. :)
 
Ovrszd, to test you could put a analog volt meter or probably a digital multimeter on your battery and watch the voltage drop while you hold the key to the glow position. At least the voltage meter on the dash of my truck does that when I'm cycling glows

Yep. I've noticed that on mine as well.

So, if an operator decided they needed more heat, how would they go about that?
 

If you thought you needed additional glow plug heat such as an extremely cold day.

Just hold it longer as Dennis indicated?? Recycle 2 or 3 times?

Evidently after 30 seconds Kubota figures it ain't doin any good.

When I held mine for over a minute it didn't appear to start any better than a 3-5 second cycle.
 
Personally if I was going to be heavy into cold climate usage I would use a block heater on a timer. If I didn't have one and it was cranking good but not starting after 30 second glow I would put a space heater on it for awhile but also consider fuel Gelling or water frozen in fuel line
 
Personally if I was going to be heavy into cold climate usage I would use a block heater on a timer. If I didn't have one and it was cranking good but not starting after 30 second glow I would put a space heater on it for awhile but also consider fuel Gelling or water frozen in fuel line

I agree. I don't start mine in extreme cold. Just trying to get clarity on what procedure should be used to get maximum benefit.

I don't have an owners manual.

Thanks.
 
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