overtemp cutoff

[bvyaprez]

Our youth association has several Kubota tractors we use for mowing and working baseball fields. We utilize volunteer parent/coaches to maintain fields. I need a temperature cut off switch I can add to our Kubota TG1860, B2400 and BX2230 tractors to prevent overheating an engine. We are replacing the engine in the BX2230 because a coach ran it hot till it quit. Any suggestions?

 

[Transit]

A] Fire the coach.

B] Have him buy the engine.

C] Keep the crud out of the radiators.

 

[Mace Canute]

A] Fire the coach.

B] Have him buy the engine.

C] Keep the crud out of the radiators.

Ditto.

 

[Transit]

Looks like a plan is forming.

 

[Soundguy]

hmm... sounds like a maintenance issue.. ( as well as an operator issue... IE.. an op should be able to read a gauge or see a lamp ).. on the other hand... it's darn hard to overheat a machine.. I've got 15 tractors... i've never overheated one of them.

not too hard.. keep the cooling system clean and flushed as needed.. clean the rad.. keep coolant in it.. etc.

if any of these are key-on machines.. look into a murphy switch gauge..

not a perfect fix.. I don't want a machine running full out working hard to 'stall' when a gauge hits a magic number.. then let my turbocharger cook from no cooldown period. perhaps have the switch gauge actuate something annowing and attention getting via relay.. like a horn or flashing lamp that can't be avoided..

soundguy

 

[Farmerford]

Murphy, as suggested by Soundguy, is an old time maker of such controls for unattended engines, but they are expensive and I don't think they sell direct or on line.

eqauges.com has "temperature switches" that close at various temperatures between about 200 deg F and 250 deg F at very reasonable prices. Use a relay to either open the key/run circuit and stop the engine or sound a loud horn or light a bright light.

The switches are all (I think) NPT threads and the Kubota ports are probably British Pipe Thread. But McMaster Carr has adapters.

I did this on a Kubota Grand L 4330 that was prone to overheating so that I could trust other family members to use it.

Hint: In selecting the activating temperature, look at the shop manual or take a direct reading on the thermostat housing with an infrared thermometer to determine the maximum safe temperture for the engine. If I recall correctly, the Kubota 4330 could safely operate at about 240 deg F, so a 220 deg F switch would be triggered frequently. I used a 230 deg F switch to sound a loud horn with a small margin of safety.

 

[RickB]

. We are replacing the engine in the BX2230 because a coach ran it hot till it quit. Any suggestions?

I'm willing to bet the radiator was plugged with debris when the coach (who had to be inattentive as well) climbed on the tractor. Murphy is indeed online
FW Murphy - Panel Systems (Mechanical Engines)
And sells a wide variety of shutdown equipment through a large number of retailers who can also be found online. I have spec'ed out a couple of systems; they can be bought and installed for less than one might think. Starting out with an engine with an electric rather than a manual fuel shutoff reduces cost significantly.

 

[Soundguy]

napa even carrier murphy switch gauges. at work we use them on some equipment.. low op shutdowns.. etc..

soundguy

 

[David_Kb7uns]

Think I read someplace here a few weeks ago somebody found that their F series Kubota had a horn hooked up to an overtemp switch, would be simple and get your attention. I think the worst thing to do is shut down an overtemp engine wtihout a cool down time. Get a 95+db piezo buzzer and try that.

David Kb7uns

 

[Thomas]

Not sure if Kubota still offer radiator cap that would make high pitch noise when hot..B7100 had such thing.

 

[brokenot]

I think the worst thing to do is shut down an overtemp engine wtihout a cool down time.

None of the equipment we have in the fleet that's equipped with Murphy magnetic switches shuts down the engine immediately when a fault occurs. Murphy sells them with a variety of delay timers built in. The stuff we have shuts down after 30 seconds.

Here's what they have available:

Magnetic Switches

 

[Leejohn]

None of the equipment we have in the fleet that's equipped with Murphy magnetic switches shuts down the engine immediately when a fault occurs. Murphy sells them with a variety of delay timers built in. The stuff we have shuts down after 30 seconds.

Here's what they have available:

Magnetic Switches

I looked at this also while there. 20 Series Temperature Swichgages

 

[jinman]

My G1800 Kubota lawn tractor has a temperature gage and an audible alarm from an overtemp switch. The audible alarm is a horn that sounds when the temperature reaches about 250 degrees F. I have tested the function by grounding the sensor and the horn is not very loud, but I think a louder 12V buzzer could be added. I would expect the TG1860 to have the same setup, but that may not be the case. I'm not sure about the B2400 or BX2230, but they might even already have something similar. Too bad they don't have these that trigger a shock collar.

 

[Soundguy]

still not an imense help.. if the op doesn't know it's overheating, then he keeps running it.. the delay just means he runs it 20 more seconds hot.. if it showed a warning like a flashing lamp, then the op could drop the throttle immediatly, and let it idle those 20 seconds to at least get some oil thru the turbo bearings for a bit before it shuts down and cokes them up.. etc

soundguy

None of the equipment we have in the fleet that's equipped with Murphy magnetic switches shuts down the engine immediately when a fault occurs. Murphy sells them with a variety of delay timers built in. The stuff we have shuts down after 30 seconds.

Here's what they have available:

Magnetic Switches

 

[brokenot]

still not an imense help.. if the op doesn't know it's overheating, then he keeps running it.. the delay just means he runs it 20 more seconds hot.. if it showed a warning like a flashing lamp....

Easy....in order for the Murphy magnetic switch to work, it needs to be wired to one of their switchgages like this:

20 Series Temperature Swichgages

The switchgage is what tells the Murphy switch to shut the engine down. The delay is built into the Murphy magnetic switch. So it's very simple to wire the switchgage contacts to sound an alarm or turn a warning light on and trigger the Murphy switch.

Our equipment has high-pitched piezo alarms that can't be mistaken for anything else on a jobsite like a back-up alarm for instance.

I'm not a big fan of dash-mounted warning lamps unless the equipment has a cab. Out in direct sunlight lamps can be tough to see, and if the operator is looking to the rear/up/sideways a good portion of the time....lamps can be missed. Additionally, if you have an operator that sees a light and ignores it....what good does the light do?

I understand the concern about turbo coking and such, but unless the operator makes it day-in day-out common practice to let an overtemp system shut him down at full-throttle, it's pretty much a non-issue.

 

[Soundguy]

I fire operators that don't look at gauges.. that's why we still have old equipment that runs.

there's plenty of people looking for work.. don't take long to find one that knows how to glance down at a cluster every 5 minutes. WAY cheaper than 47 safety idiot proof systems being retrofit to some piece of equipment

soudnguy

 

[brokenot]

don't take long to find one that knows how to glance down at a cluster every 5 minutes. WAY cheaper than 47 safety idiot proof systems being retrofit to some piece of equipment

I hear you, but what's going on in between those once-per-five-minute glances at the gauges?

I'm not "Big Brother", but if I've set a switchgage to a given temp, (or whatever else the parameter may be), then I know it'll shut down. Try as I might, I can't control what the operator sees/thinks/feels/interprets when a gauge reads "X", let alone what his/her reaction will be to that situation.

I do know that if my sole means of protection is a gauge, and the operator sees an abnormal situation and chooses to ignore it, then that same operator will deny noticing anything was wrong prior to the expensive ka-boom. The burden of proof would then fall to me.

And I wouldn't be able to prove a thing.

 

[Soundguy]

at that point it's not a proof issue.. it's a broken down machine.

once you pop the top it will be telltale what happened. I like to find ops that treat the equipment like their job / eating depends on that machines health.

soundguy

 

[some zilch]

someone who cant look down at gauges and know the general operating condition has no place on a machine not owned by them.

 

[Egon]

I hear you, but what's going on in between those once-per-five-minute glances at the gauges?

I'm not "Big Brother", but if I've set a switchgage to a given temp, (or whatever else the parameter may be), then I know it'll shut down. Try as I might, I can't control what the operator sees/thinks/feels/interprets when a gauge reads "X", let alone what his/her reaction will be to that situation.

Only way to tell if an operator isn't watching the gauges is after the machine is broke down in an area related to the gauges.

In industrial situations there are usually sound and light alarms with one being a warning and the other a shutdown.