fire alarm sensor

PleasureBay · Post by **PleasureBay** » Thu Apr 07, 2016 5:17 pm

Does anyone know where to find the small round sensor mounted under the bridge ladder that controls the fire alarm in the emergency panel? Mine started going off for no reason and I disconnected it but the alarm light is still on. I tried bypassing it but I can't make the light go out I have temporarily disconnected the alarm bell.

h2ojst · Post by **h2ojst** » Fri Apr 08, 2016 4:40 am

Jack, They're thermal switches and I think that Kidde still manufactures them, but something doesn't sound quite right. Are you sure that you bypassed the correct switch? There are several mounted throughout the engine room areas & mine had one aft in the geny hatch area also. The light & the bell should go off when the correct switch is bypassed.

PleasureBay · Post by **PleasureBay** » Fri Apr 08, 2016 4:47 pm

I have to look for other sensors. The scematic only shows the one behind the port engine, if I'm reading it correctly. I'll check tomorrow. My boat does not have an automatic fire suspression system.

PleasureBay · Post by **PleasureBay** » Sat Apr 09, 2016 7:09 am

Thanks Joe, I found all the sensors. Now I just have to find a replacement for the bad one.

PleasureBay · Post by **PleasureBay** » Sun Apr 10, 2016 3:34 pm

Does anyone know where to get several of the fire sensors used on the Bertrams? They are about 1" - 1.25" in diamter.

Rick · Post by **Rick** » Mon Apr 11, 2016 6:00 am

Joe thinks Kidde still makes them, might want to start with them. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

h2ojst · Post by **h2ojst** » Mon Apr 11, 2016 8:54 am

Mine had a CO2 fire suppression system that I removed & replaced with a newer version. I also removed all the sensors but I think at the time that I did find them available from Kidde. Fireboy might also stock something similar, but someone has to still make them. It's just a heat sensing switch that opens at a set temperature.

PleasureBay · Post by **PleasureBay** » Mon Apr 11, 2016 1:43 pm

Thanks to all for your help and info. Danny from High Tide called me back this afternoon and said he was able to locate the original type sensors. A company, I think he said in CA, makes them. I had already checked into a pencil type sensor from Edwards Security.

Aquaman · Post by **Aquaman** » Mon Apr 11, 2016 4:02 pm

PleasureBay The sensors and alarm bell is made by Aqualarm

PleasureBay · Post by **PleasureBay** » Thu Apr 21, 2016 2:18 pm

I received the new alarm sensor and put it in the system but the alarm is still softly buzzing. Does anyone know how to trouble shoot the alarm system? Especially the fire alrm leg.

Rick · Post by **Rick** » Fri Apr 22, 2016 4:08 am

I think maybe the new sensor is set at the wrong resistance. Try measuring it with an Ohmmeter and then measure another that is still good in another location, but remove one of the wires first for accuracy. Rick Ticket 85 SF Merc 454 MPI's Falmouth, MA

WetProcess · Post by **WetProcess** » Fri Apr 22, 2016 7:58 am

The original sensors are NOT thermistors (change resistance with temp) they ARE what is know as snap switches they are normally OPEN when cool and "snap" closed at 190F. They may or may not reset depending on any fire damage. A low buzzing is indicative of less than 12V reaching the bell. Al

PleasureBay · Post by **PleasureBay** » Fri Apr 22, 2016 8:39 am

Thanks, I'll try to check the resistance with my meter.