Murphy Swichgage

[Charolais]

After reading the thread about the oil plug I thought I'd post about Murphy Swichgage. I expect many of you here have never seen or heard of this system. In my area most all farm tractors that are used to power irrigation pumps use Murphy Swichgage. It's a must for irrigating. You start the system up and leave for hours and there's no one to watch the tractor. The ones I've seen have a gage for oil pressure and another for temp.

They're also great for hired help or someone with little experience with running equipment. Both these gages are wired to drop out the 12 volts holding the fuel solenoid open to the injector pump.

When you are ready to start the engine there is an override button that has to be installed so you can get the oil pressure up so the oil pressure gage will take over.

Just this past May I was helping a neighbor prepare some bean land and was running his JD 110HP tractor,pulling a 14' leveling disk. Been working for 3 hours and everything was fine. Stopped and talked to him for a few minutes and started back out in the field. Got half way across the field and the engine shut down. The coolant had reached 198 which was the set point he had set on the gage. I got out of the cab and checked the coolant level. It was low but not boiling. Walked across the field and got some water from a house near by. Poured in a gal. and got it running to drive to that house to get more water.

When you think about it, every tractor/engine should have this system. I know in the past I've knocked off an oil filter or two. I shut down the engine in time but if it had been a hole in the pan or a oil line came off I may not have seen it.

Anyway I just thought some of you may be looking for something like this. It's cheap when you think a new engine or a total overhaul will cost.

Oh and these systems are nothing new. I know they've been around since the early 70's and maybe before.

Here's a place that sell them and most farm tractor dealerships can get them both already mounted in a metal box for mounting on the tractor or in the cab.

https://www.surplusunlimited.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=700-52

 

[Willl]

Nice but $45 ?
Plus you got to use their sensor = even more $$

In my trade we have been using something very similar to these.
And their adjustable.

Aerocraft Parts & Avionics

 

[Charolais]

I just used that site as an example. The point was, it's protection. I have one tractor that I put a high pitched alarm for the oil pressure. I don't trust lamps.

Murphy Swichgage has been the leader in this area for a long time. The product is trusted. It's saved a lot of high dollar engines. Anything is better than nothing.

 

[patrick_g]

Charolais, You can lead a hourse to water but whether or not it drinks is another matter (old Polish saying)

I keep a constant eye on my temp gauge as in dry times (like now) I have to stop every so often to dump junk off the screens protecting the radiator, oil cooler, and A/C condensor. Thanks for the reminder about the audio alert, I have been meaning to put Sonalerts across idiot lights which are a distant second place to real gauges.

Low oil pressure and over temp shutdown are super cheap insurance and saving $ on the sensors is not a good investment. I have a filter minder sensor that lights a light on the dash if the air filter draws with too much dificulty. It was defective within a couple years and the OEM part they gave me to replace it was defective out of the box. The next one worked (third time is a charm?) In the words of a past president, "trust but verify." It would be good to test the safety devices to ensure they work correctly prior to installation and trusting them with thousands of dollars of engine.

Pat

 

[Charolais]

Pat, you wrote it better than I. I'm not the best writer or good with words as many of you are. You got my point across . Thanks.

I'm sure there are many folks on this site that are thinking right now about a safety system like this. Reading here for several year now I know there's lots of folks that get in to some nasty work with their tractors, just like I do. Anything that will shut that engine down or sound off loud enough to make you stop is worth the money. Testing from time to time is very important also.

Above all, Save the engine!!!!

 

[Soundguy]

If your oil sensor is a grounding type unit, a NC relay , and a momentary push button switch to be used as a bypass switch could be hooked up in tandem with an oil lamp, and the 12v injector cutout. for about 7$, and do the same thing as a murphy switch.... and use the tractor's oem grounding type oil sensor made for the 'lamp on = no oil pressure ).

Connect ignition power to coil of relay, connect other side of relay coil to oil sensor. connect fuel cutout solenoid power thru the NC connections on the relay.

With key on, and tractor not running there is no oil pressure.. Oil lamp is on, and relay kicks fuel solenoid out.. hold in bypass switch which is place inline with relay coil wire from ignition.. this lets fuel solenoid operate.. Takes 15? minutes to instal? alarm horn can be added to same circuit.. connect alarm horn across relay contacts.. Horn sounds any time warning lamp would be lit, unless bypass switch as held in.

Soundguy

 

[DieselPower]

I have been using Murphy switch gauge shutdown control box's for years on stationary generators and heavy construction equipment. This is the box I usually use which is their WAI series. WAI Series When you buy the kit it comes with the temp probe and preasure sensor in the kit. Depending on the exact setup of the system you buy they run a couple of hundred dollars but that's cheap compared to a engine failure repair. They make the heaviest duty shutdown systems you can buy and seem to last forever. They will also custom build any type shutdown system you can dream up (for a price of course).

 

[patrick_g]

SoundGuy, Thanks for sharing a very useful idea. About the only nit to pick on it is the lack of adjustability on when the oil pressure sensor makes contact. I don't know but suspect there may be a choice of different pressures depending on the particular switch you buy so the adjustability thing would be a non issue.

I wonder how many folks out there have used pre and or post lubers. They are another terrific life extension idea for engines except they do you good every time you start (and or stop), a proactive immediate benefit and not an insurance policy like the low pressure or over temp shutdown.

I have seen preluber designs that are super cheap and simple for DIY and can be built with no motor, pump, or even a solenoid valve if you want to economize with no reduction in performance.

Pat

 

[slowrev]

Patrick,
An adjustable pressure switch would be nice and you coul dhave it trip at a higher pressure if you wanted, but Soundguys will cover most non commercial needs. also adjustable temp light sensors are available. I got one from JC whitney to turn on an electric fan in a tractor. I needed a pusher fan but none were available, so I put an electric fan on it. Works nice, and I can reverse it for winter when I want the heat on me.

 

[Soundguy]

The circuit I spoke of would work with the tractors oem (grounding - lamp) style sender, and turn on at whatever psi the oil lamp would come on, as determined by the factory. Thus, if the sender kicks the oil lamp on when the oil pressure drops to 6psi ( very common value).. then the relay would also kick on then, thus killing the engine via fuel starvation.. so if the oem specified a correct value of oil lamp to alert you to a low oil situation.. then my simple circuit will kill the engine at that set warning threshold level, as determined by the manufacturer.. etc. If yuo wanted more of a margin.. i guess you could always get a higher psi limit sensor.. etc.

Soundguy

SoundGuy, Thanks for sharing a very useful idea. About the only nit to pick on it is the lack of adjustability on when the oil pressure sensor makes contact. I don't know but suspect there may be a choice of different pressures depending on the particular switch you buy so the adjustability thing would be a non issue.

I wonder how many folks out there have used pre and or post lubers. They are another terrific life extension idea for engines except they do you good every time you start (and or stop), a proactive immediate benefit and not an insurance policy like the low pressure or over temp shutdown.

I have seen preluber designs that are super cheap and simple for DIY and can be built with no motor, pump, or even a solenoid valve if you want to economize with no reduction in performance.

Pat