Replacing Accenta6 Door Contact

[fixsheff]

Hi, I have an Accenta6 alarm and have just had the front door replaced taking great care to find and reinsert the contact sensors. These are an oblong magnet in the door and a wired glass cylinder in the frame which leads down to the power box in the cellar. Unfortunately the door slammed shut and broke the glass cylinder containing the metal contacts.
I haven't been able to find anything online about this type of sensor and am not sure whether it is easily replaceable. There are two wires attached to either end, a red one and a yellow one. Is it just a case of finding a new glass type cylinder contact and reattaching the wires or will removing them cause tamper type problems? Thanks for any help.

 

[bernardgreen]

Google search for magnetic reed switch

 

[sparkymarka]

Screwfix £1.49

Tate Door / Window Wired Magnetic Surface Contact 65547

 

[fixsheff]

The sensor is fitted flush in the frame and is like a glass cylinder with two strips of metal which open and close via a magnet in the door. Thanks for the name which makes searching easier.
Assuming I can find one, is it just a question of reconnecting the wires at either end of the cylinder? The alarm is in day mode at present, will disconnecting in this mode cause a problem or can I just fit a new one?

 

[bernardgreen]

If it is ( was ) just the glass tube with a contact at each end then you can remove the wires from the remains of the old one and connect ( normally by soldering ) to the new one. The new reed does not have to be the exact same size as the old one. If you have a means to test for continuity ( the contacts being closed ) it is a good idea to check the new one operates when the magnet is twice the normal distance from the reed. ( normal being the distance between them when the door is shut.

When soldering keep the solder joint as far from the glass as you can as over heating the metal where it goes into the glass can damage the seal between the metal and the glass. Or you hold the metal between joint and glass in metal pliers to take away the excess heat and thus get the joint closer to the glass if that is necessary due to the space available in the door frame.

Damage to the seal can allow air and moisture to creep inside the glass and this may corrode the contacts over time.

 

[EightyTwo]

The small door contacts (like the CQR SC516) often just have the leads under the terminal screws - no solder. These screws are usually tinned (silver colour) and the other screws are brass. Some manufacturers have the tinned terminals at the ends and some in the middle but the two silver screws are usually the ones for the contact itself.

You may have resistors or a second pair of wires twisted together under one screw. Take a photo before you start and look at the Alarm Sticky on this forum.

New door = new contact? As it's a surface contact, it's hardly worth repairing - just fit a new one... Nice, easy half hour job for Saturday morning.

One tip - fit the contact by wiring it first. Drill the hole for the first screw and do it up fairly tight. Adjust the contact so that it is perfectly horizontal/vertical and, carefully, drill the pilot hole for the other screw and secure it. Repeat the process for the magnet making sure that it is parallel with the contact. If it isn't, it won't affect the performance of the contact but you'll notice it everytime you go out of the front door!

 

[EightyTwo]

If you only have two wires and no resistors, you won't get a tamper when you disconnect (or short circuit) the wires. Just leave the alarm panel in day mode.

Don't forget to "walk test" the contact when you've finished.

 

[sparkymarka]

Was this reed switch filled in the frame with wood filler ? Post a picture

 

[fixsheff]

Thanks all for taking the trouble to reply. The sensor was held in place with what looked like ordinary filler. The wires seemed to be taped on although I don't know whether they are soldered under the tape. Part of the problem when trying to reinsert it was wondering whether it would work covered in filler. It seemed to need to be quite near the surface to function with the magnet.
Sourcing these glass cylinder sensors seems tricky unless my search skills are poor. (Anyone in Sheffield know where you can get one from?)
Because it has broken I don't know what size it should be but am reassured to know that any size could function. And does it matter if the current metal strips touch even though it is in day mode? My fear is that I'll trigger the alarm and be unable to switch it off.
I will try to put up some photos later if I can work out how to do it.
Thanks again for your help.

 

[sparkymarka]

This was the old way of fitting door contacts before the 20mm concealed door contact, have you started chopping out your new door yet ? If not just fit a concealed contact ... If you have started try bardwells on abbeydale road. 01142552886 ......pm me if you need a 20 mm door contact

 

[fixsheff]

I've finally managed to get hold of a larger magnetic reed switch and am trying to replace the smashed one. After digging a bit more filler out it appears that there are two more intertwined wires (black and blue) which I'm not sure about. I haven't damaged them but am about to disconnect the red and yellow wires from the ends of the broken sensor and try to solder them to either end of the new one. Given my discovery of these two new intertwined wires is it still safe to do so without the alarm going off? And if it does can I just cancel with my normal code? Thanks for your help.

 

[sparkymarka]

They will be the tamper pair and will be soldered together in a loop, as long as you don't break the loop they should be ok

 

[fixsheff]

Cheers Sparkymarka - it's one of those jobs which takes on a life of its own when you don't know what you're doing. Fingers crossed.

 

[sparkymarka]

Is it an old SS alarm ?

 

[fixsheff]

Finally managed to fix the door contact using a smaller 20mm magnetic reed switch. The 50mm replacement which I tracked down wouldn't work.
Thanks to all who helped, I'll be more careful with the door slamming shut next time.