Where can I find one of these? My thermostat gauge in the engine room with the memory needle is not working anymore. I searched on Google without success. Any ideas? Thanks David
That is a Murphy shut down gauge does your Eagle have the Murphy safety shut down system,go to FW Murphy and look under engine control
That's not a 'memory needle', but rather it's a set point.
Murphy switch gauges are still made. The purpose of the second stationary needle is to set a switch point in the gauge. These are usually used on oil pressure and temperature gauges, and they are used in conjunction with a 'Murphy Switch' which is nothing more than a really fancy relay.
I used two of these on the generator on my first bus, one for oil and one for temp, so that the Murphy Switch would shut things down if they crossed the set point.
My step van used this also, and that one had a built-in buzzer until the oil pressure came up. They can be ordered with a delay to give the pressure time to come to spec before shutting down, otherwise starting a cold engine would be difficult.
In your situation, you'd have to figure out if someone used the gauge simply as a gauge cause they had nothing else on hand, or if they have it connected to a shut down circuit. It's quite possible that it's working perfectly and doing its job, but that you haven't crossed the set point yet to cause a shut down.
http://www.murcal.com/fwm_production/fwmpc_home.html
On stationary engines the oil pressure is set at 0 to 5 and you push the button on the gauge to bypass to start the engine,everytime they get a new guy at the mines I have to make a service call because a generator won't start,Murphy makes generator controllers too they are a lot more than a few relays
This is the Murphy Switch I used to build the shutdown system on my Perkins powered generator.
http://www.murcal.com/Catalog/Magnetic-Switches/760A-15-12-Magnetic-Switch
I combined it with two switch gauges - oil and temp.
It has a built-in 15-second delay before shut down, eliminating the need to hold the button till the oil pressure builds.
All I needed besides this was the start button and toggle switch for the fuel solenoid.
Quote from: richard5933 on August 26, 2020, 07:20:29 PM
This is the Murphy Switch I used to build the shutdown system on my Perkins powered generator.
http://www.murcal.com/Catalog/Magnetic-Switches/760A-15-12-Magnetic-Switch
I combined it with two switch gauges - oil and temp.
It has a built-in 15-second delay before shut down, eliminating the need to hold the button till the oil pressure builds.
All I needed besides this was the start button and toggle switch for the fuel solenoid.
The controllers work a little different because it controls thing other than oil pressure and tempature shut down,they will shut one down with problems like over speed, pretty costly to replace too
Quote from: luvrbus on August 26, 2020, 07:30:24 PM
The controllers work a little different because it controls thing other than oil pressure and tempature shut down,they will shut one down with problems like over speed, pretty costly to replace too
If you're talking about electronic control boards or electronically controlled generators, then perhaps.
But for mechanical generator controls, the magnetic switch I linked to pretty much makes up the heart of the system. You can add sensors and switch gauges for most anything to the magnetic switch, such as the over speed protection as you mentioned.
When I was building the control board for the generator's engine, I spoke with the folks at Murphy to learn more. The choice was essentially to purchase one of their pre-built (and costly) units or to choose the elements that I needed and to install them into the existing box housing the generator head's own control board. I chose to pick and choose what I needed. I would not say their parts are cheap, but doing it this way at least made it possible within my budget.
It is strictly a thermostat with a memory needle that is pushed to the highest temperature reached. It is not connected to any type of shutdown switch. I can't find one on google
Quote from: luvrbus on August 26, 2020, 04:04:29 PM
That is a Murphy shut down gauge does your Eagle have the Murphy safety shut down system,go to FW Murphy and look under engine control
. No. It is only a gauge. It pushes the memory needle to the highest temperature
I found some :
https://www.dwyer-inst.com/Product/Temperature/Thermometers/Dial/SeriesBTM3
That would be handy in the engine bay to track heat problems, for sure.
Quote from: hogi6123 on August 27, 2020, 11:02:28 PM
I found some :
https://www.dwyer-inst.com/Product/Temperature/Thermometers/Dial/SeriesBTM3
Thanks hogi
I rolled it over. It is a Murphy. I found the model number.
I spoke with a Eagle parts guy he says that was a Houston Metro order only, and they ordered those through Murphy in Tulsa Ok,he said where they are now he has no idea but Jefferson had those in stock,and the gauge is made by Stewart Warner for Murphy
I think I would prefer to install a digital gauge with memory function
This one seems to have it. But also a 6' hose:
http://www.murcal.com/Catalog/A20-Series-Temperature-Swichgages/A20TG-TT-250-6-1-2-10706204-Temperature-Swichgage
https://ebay.com/itm/A20TG-TT-250-6-1-2-10706204-Temperature-Swichgage-/392767081573
Got her installed. All is well. It was $150. Somewhat pricey, but I like having this in the engine room. Found it on ebay. New old stock.
David
I found one of these gauges at a good price, and it seems like having a temp gauge in the engine bay would be a good idea.
Anyone know if there is a third port on the thermostat housing or some other place to install the sensor for this? I have two ports - one is in use for the dash temp gauge and the other is in use for the over-temp shut down system. Would love to find a third port hiding somewhere on my 8V71.