Exhaust Pipe Temp Sensor Connections

[Four Suns]

I have 250 degree temp sensors on the exhaust pipes on my QSM-11 diesels. The idea here is that when the pipe gets that hot, the raw water cooling must have stopped. Well... as some of you recall I forgot to open a seacock last year and ended up with this damage to the impeller:

The temp sensor on the starboard engine did not register a fault and warn me via the Sea Ray Systems monitor as it should have. Granted I didn't overheat the engines and caught it when the coolant temp went up just 10 degrees over normal so maybe if I would have let it overheat more it would have gone off...

Additionally, the old one on the port exhaust has been bumped a few times and the connectors broke off. I ended up ordering new ones from the exhaust company in Florida but got 220 degree ones instead of the OEM 250 degree ones. Here's a picture of the old and new ones:

Note the broken off spade connectors on one of the old ones. Here's a close up of one of the new ones:

My question is this... How does one go about hooking the two wires to those small spades? The old ones appeared to have some of the bigger spades welded on the smaller ones so a female spade connector could be used... Any ideas? Mr. Crimp Man? You out there?

 

[wingless]

The typical size for FASTON plug / receptacle is a 0.250" blade. The other standard sizes are: 0.312"; 0.187" and 0.110".

The blade thickness should also match for the mating parts.

These parts are available on Digi-Key.

 

[Four Suns]

The tabs on the new sensors are 1/8". Digi-Key did not have disconnects in that size. The bag of sample terminals that Presentation sent me had .110" and .187" disconnects and they were too small or too big respectively.

 

[Four Suns]

These terminals may work:

http://www.tnb.com/ps/endeca/index.cgi?a=nav&N=592+1010+1131+4294960850+4294960845+4294962448&Ntt=

But I don't know the tab thickness size on that sensor. The terminals are for 0.02" or .032" thickness tabs.

 

[wingless]

A 1/8" tab is: 0.125" wide, so those 0.187" FASTON receptacles would be a sloppy fit.

Why not just make the part into an assembly by poking a stripped wire through the hole, twisting it around itself, apply just enough solder for the joint, to avoid wicking up the insulation, then heat shrinking the junction?

A male FASTON tab could be applied to the end of the pig tail to mate w/ existing wiring.

The solder has issues in marine applications, but so would a failed FASTON connection.

A soldered pig tail may prove better in the long haul than that small tab trying to hold a FASTON junction. That tab now also has the stress of an extra bend.

Alternately, a Dremel tool could transform that 0.125" tab into a 0.110" tab.

 

[Four Suns]

A 1/8" tab is: 0.125" wide, so those 0.187" FASTON receptacles would be a sloppy fit.

Why not just make the part into an assembly by poking a stripped wire through the hole, twisting it around itself, apply just enough solder for the joint, to avoid wicking up the insulation, then heat shrinking the junction?

A male FASTON tab could be applied to the end of the pig tail to mate w/ existing wiring.

The solder has issues in marine applications, but so would a failed FASTON connection.

A soldered pig tail may prove better in the long haul than that small tab trying to hold a FASTON junction. That tab now also has the stress of an extra bend.

Alternately, a Dremel tool could transform that 0.125" tab into a 0.110" tab.

Wow... I can't divide 1 by 8... what a dumbass. Those .187 terminals won't work. Nevermind.

I thought about the solder connection but, again, with the engine vibration, that idea doesn't seem too smart (plus it definitely violates ABYC rules)

I don't think bringing the tab down to .110" would work as the hole in the tab has to align with the bump in the female connector as well.

 

[wingless]

I thought about the solder connection but, again, with the engine vibration, that idea doesn't seem too smart (plus it definitely violates ABYC rules)

Come over to the dark side, Luke.

Those flimsy tabs shouldn't support a FASTON, plus the wiring.

 

[Four Suns]

Come over to the dark side, Luke.

"I'll never join you!"

 

[tobnpr]

I want to add EGT gauges or at least an "idiot" buzzer; that looks like a simple installation. I don't have any metal exahust piping, though (exhaust hose straight out from the turbo). Would those work clamped to an exhaust hose, or does it need to be a metal exhaust tube? Is that just a temp operated SPST switch?

I was going to go with a pyrometer/thermocouple setup, but it's a lot more $$ and more difficult to install.

http://www.fwmurphy.co.uk/products/temperature/temperature_exhaust_pyro.htm

 

[Four Suns]

I want to add EGT gauges or at least an "idiot" buzzer; that looks like a simple installation. I don't have any metal exahust piping, though (exhaust hose straight out from the turbo). Would those work clamped to an exhaust hose, or does it need to be a metal exhaust tube? Is that just a temp operated SPST switch?

I was going to go with a pyrometer/thermocouple setup, but it's a lot more $$ and more difficult to install.

http://www.fwmurphy.co.uk/products/temperature/temperature_exhaust_pyro.htm

I guess it depends on what you are putting the sensor in for. I'm not convinced that the 220/250 temp sensor on my exhaust elbow does any good at determining if I have water flow... based on the one failure I've had. It is an SPST switch that is normally open and when the temp gets above the rating, it closes...

I don't know if you've seen these:

http://www.borelmfg.com/products_alarm.htm

They actually can go on non-metallic exhaust hose and you'll notice the temps are set to 165-ish and not the high 220/250 that the things Sea Ray put on my boat. But that's measuring the hose temp and it assumes there if water is on the other side the temp is below 165 and if there is no water on the other side, the temp rises above 165... I should probably send a note to Tony Athens at Boatdiesel and ask him his opinion...

I have found some inline sensors that physically measure the water flow but they are only up to 2" in diameter and I have 2.5" diameter system.

 

[wingless]

I want to add EGT gauges or at least an "idiot" buzzer; that looks like a simple installation. I don't have any metal exahust piping, though (exhaust hose straight out from the turbo). Would those work clamped to an exhaust hose, or does it need to be a metal exhaust tube? Is that just a temp operated SPST switch?

I was going to go with a pyrometer/thermocouple setup, but it's a lot more $$ and more difficult to install.

http://www.fwmurphy.co.uk/products/temperature/temperature_exhaust_pyro.htm

Yes, it's a normally open SPST thermostat, w/ built-in hysteresis.

That part is available from a plethora of manufacturers, w/ a myriad of operating temperatures and a superfluity of configurations.

It is important to have good thermal coupling to the monitor point. Poor thermal coupling increases the reaction time.

An infrared camera is handy to find the best spots to monitor. Alternately, a thermocouple may be used to sample potential locations.

 

[Four Suns]

These are the guys that did the exhaust on my boat (OEM by Sea Ray)

http://www.deangelomarine.com/index2.htm

Annoying web site... If you go to their online store, you can see these sensors. The sensor mounts to a thick piece of metal welded to the metal elbow where the raw water enters the exhaust.

I should probably get the temp of that spot when the engines are operating "normally" and see how far off that sensor is....

 

[fwebster]

DeAngelo is usually very helpful if you can get past sales folks to technical people. Call them and ask then what connectors they specify for their sensors.

 

[Four Suns]

DeAngelo is usually very helpful if you can get past sales folks to technical people. Call them and ask then what connectors they specify for their sensors.

What fun is that? Mr. State-the-obvious.

 

[wingless]

Come over to the dark side, Luke.

"I'll never join you!"

Please share your final solution young Padawan.

 

[mawyatt]

I have 250 degree temp sensors on the exhaust pipes on my QSM-11 diesels. The idea here is that when the pipe gets that hot, the raw water cooling must have stopped. Well... as some of you recall I forgot to open a seacock last year and ended up with this damage to the impeller:

The temp sensor on the starboard engine did not register a fault and warn me via the Sea Ray Systems monitor as it should have. Granted I didn't overheat the engines and caught it when the coolant temp went up just 10 degrees over normal so maybe if I would have let it overheat more it would have gone off...

Additionally, the old one on the port exhaust has been bumped a few times and the connectors broke off. I ended up ordering new ones from the exhaust company in Florida but got 220 degree ones instead of the OEM 250 degree ones. Here's a picture of the old and new ones:

Note the broken off spade connectors on one of the old ones. Here's a close up of one of the new ones:

My question is this... How does one go about hooking the two wires to those small spades? The old ones appeared to have some of the bigger spades welded on the smaller ones so a female spade connector could be used... Any ideas? Mr. Crimp Man? You out there?

Gary,

Why not remove the old spade lugs and have them brazed/welded to the new sensor lugs.

 

[wingless]

Gary,

Why not remove the old spade lugs and have them brazed/welded to the new sensor lugs.

'cause ABYC didn't say so, duh.

 

[Four Suns]

'cause ABYC didn't say so, duh.

No... I am concerned that would damage the sensor.

 

[wingless]

I thought about the solder connection but, again, with the engine vibration, that idea doesn't seem too smart (plus it definitely violates ABYC rules)

Remind me of the ABYC stance on FASTON connectors.

 

[mawyatt]

No... I am concerned that would damage the sensor.

A spot weld shouldn't generate enough heat outside the weld area to damage anything...but you must find someplace that does spot welds which might prove difficult.