Exhaust alarm sensor

[ianc1200]

I managed to break the spade connection on one of the sensors, anybody able to recognise this? (edit to say this is the one from the port engine, the one i didn't break. Also can see there are letters/numbers which might identify it so will look again)

 

[wonkywinch]

Why do boat builders insist on using mains flex?

 

[rogerthebodger]

Temperature-sensitive bimetallic disc​

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The switch is designed with a temperature-sensitive bimetallic disc that is the actuator for the thermally and electrically isolated contacts which open when the ambient or surface temperature increases to the operating snap point of the metal disc.

There are different operating temperatures which will be indicated on the unit

RS components are a UK supplier

 

[ianc1200]

Temperature-sensitive bimetallic disc​

---

The switch is designed with a temperature-sensitive bimetallic disc that is the actuator for the thermally and electrically isolated contacts which open when the ambient or surface temperature increases to the operating snap point of the metal disc.

There are different operating temperatures which will be indicated on the unit

RS components are a UK supplier

Many thanks. Certainly do look like them.

 

[PaulRainbow]

Many thanks. Certainly do look like them.

What is the sensor connected to Ian, just an alarm buzzer, or do you get a temperature readout ?

That crack in the brown wire needs sorting, even if it's just some super glue.

 

[ianc1200]

It's an alarm, not a readout. Will sort crack in wire. Have found the actual device is

Normally Closed KSD301 Automatic Reset Thermal Switch High Temperature Protection

seemingly sold by the shipload, so seeing if similar spec switch available from the RS Components site.

 

[Plum]

It's an alarm, not a readout. Will sort crack in wire. Have found the actual device is

Normally Closed KSD301 Automatic Reset Thermal Switch High Temperature Protection

seemingly sold by the shipload, so seeing if similar spec switch available from the RS Components site.

Yes, lots of that type online but what temperature do you require it to make contact? I assume your existing one is marked with a temperature.

 

[ianc1200]

Hi Colin, the switch has only a item number, but the spec from the page noted above says 0 - 180 degrees C, and an electrical rating of "16A/250V, 15A/125V, 10A/250V". Not sure if it should be used with 12V, but clearly is.

Any recommendations re type of glue to use?

 

[rogerthebodger]

Hi Colin, the switch has only a item number, but the spec from the page noted above says 0 - 180 degrees C, and an electrical rating of "16A/250V, 15A/125V, 10A/250V". Not sure if it should be used with 12V, but clearly is.

Any recommendations re type of glue to use?

would clanp the 2 lugs on to the elbow using 2 stainless steel worm drive clips to allow easy removal

 

[Rum Run]

It's an alarm, not a readout. Will sort crack in wire. Have found the actual device is

Normally Closed KSD301 Automatic Reset Thermal Switch High Temperature Protection

seemingly sold by the shipload, so seeing if similar spec switch available from the RS Components site.

Would it be a normally-closed? That's an odd way to do it as unless there is some intermediate circuitry the buzzer will sound immediately. A Normally-Open switch will close at the rated temperature, allowing voltage through a buzzer, light or whatever. Just sticking my nose in though!

 

[Plum]

Hi Colin, the switch has only a item number, but the spec from the page noted above says 0 - 180 degrees C, and an electrical rating of "16A/250V, 15A/125V, 10A/250V". Not sure if it should be used with 12V, but clearly is.

Any recommendations re type of glue to use?

It appears from the page you quoted that they can supply any temperature between 0 and 180 so you need to know at what temperature your ones are . For example, if you buy from this supplier you have a choice of 23 different temperatures. KSD301 Temperature Controlled Switch 250V 10A Normally Open/Closed Range 40-190℃ | eBay UK

 

[Plum]

would clanp the 2 lugs on to the elbow using 2 stainless steel worm drive clips to allow easy removal

Absolutely. Unless your adhesive will withstand the maximum temperature your exhaust could reach, if your engine overheats due to a lack of raw water flow the sensor may activate the alarm or it may fall off before the alarm sounds.

 

[ianc1200]

It appears from the page you quoted that they can supply any temperature between 0 and 180 so you need to know at what temperature your ones are . For example, if you buy from this supplier you have a choice of 23 different temperatures. KSD301 Temperature Controlled Switch 250V 10A Normally Open/Closed Range 40-190℃ | eBay UK

Colin - thanks for that link. Had given up, thought I need to buy a container load from Taiwan.

Paul Rainbow - have you got a suggestion as to a sensible "danger" temperature?

 

[ianc1200]

Would it be a normally-closed? That's an odd way to do it as unless there is some intermediate circuitry the buzzer will sound immediately. A Normally-Open switch will close at the rated temperature, allowing voltage through a buzzer, light or whatever. Just sticking my nose in though!

We've been thinking this through also. The buzzer goes off if there's a break in the continuity. I've disabled it by connecting the two wires together. But does "closed" mean there's continuity when the danger temperature not reached? And it "opens" ie breaks the continuity, if it does reach that temperature - or the other way round.

Edited - Colin's (Plums) EBay link had the answer.

 

[billskip]

We've been thinking this through also. The buzzer goes off if there's a break in the continuity. I've disabled it by connecting the two wires together. But does "closed" mean there's continuity when the danger temperature not reached? And it "opens" ie breaks the continuity, if it does reach that temperature - or the other way round.

Edited - Colin's (Plums) EBay link had the answer.

View attachment 196226

Yes

 

[Plum]

Colin - thanks for that link. Had given up, thought I need to buy a container load from Taiwan.

Paul Rainbow - have you got a suggestion as to a sensible "danger" temperature?

The switching/danger temperature will depend on many factors, such as where the sensor is placed in relation to the point of water injection, whether the sensor is external, etc. and could be anything between 50 and 90 degrees C. I have a digital display and can set the alarm switching temperature which I have at 10 degrees higher than the maximum I can achieve flat out, which is 55 degrees switching temperature.
This is the type I have, fitted 10 years ago. Pardon our interruption...

 

[rogerthebodger]

To find the switch temperature I took my boat out at full throttle and measures the max temp of the elbow.

I then added 20-30 degrees to this as a warning temperature

 

[ianc1200]

Re temperature - I've got one off now. The backside of it has "A/ 060 - 15 4308"

The manufacturers detailed spec says it is made for an electric kettle, A is contact type, 060 is operating temperature, 15 might be the temperature tolerance, can't make out what the 4308 means.

T24 KSD301 16A 250V Bimetal Disc KSD301 Thermostat For Electric Kettle about half way down page.

But what interests me is the 060 which I'm reading is when the switch opens/continuity is broken/alarm sounds.

The dashboard has a sign saying normal operating temperature is 85 - 93 degrees C, but that is the engine temperature, not the exhaust temperature which has been cooled by seawater. On another boat I have, I took out a direct cooled BMC 1.5L and replaced with a Nanni 62hp freshwater cooled with a heat exhanger. When the BMC was running I could barely put my hand in the exhaust water - it was so hot, and was suprised how cool/cold the Nanni exhaust water was. Yet to try these Cummins but am guessing the exhaust won't reach 60 degrees C. Will try soon but in the meantime at such cheap prices on Ebay use the 60 degree one and see how it goes.

 

[harvey38]

Morning Ian,

I'm not sure what you have at the other end of the sensor but I'm about to order a twin display and sensors for the lower helm on Tolerance. If it works well, I'll add another display to the upper helm.

Shop

It appears they sell sensors separately too.

 

[ianc1200]

I've added CCTV to the engine room but only have the display in the lower helm as yet, need to add to the upper where it could be more important. Also rear view camera to the radar arch and display at the lower helm. The exhaust alarm is to a dedicated panel at the back of the saloon and very, very loud.