I have one zone which has 2 contacts on same zone in 2 sheds 

I have altered one shed so it has two doors on now so I want 3 contacts

i did this and it worked for a couple of days then it kept saying the door was open but it’s not so I went back to 2 contacts for now

its  Orisec panel

Modern panels work best with 1 eol device per zone

 

However-

 

depends on the model of contacts

how they are wired

 

ect...

 

It’s just a standard door contact

I just wouldn't, especially on a modern panel with more options. One zone per device, so you can diagnose any problems.

Your sketch seems alright assuming it's DP, time to get the multimeter out take everything apart and work out what's going on.

Is it a 6 core cable?

If so just use eol contacts \resistors and put 1 on each circuit.

Id only put 2 on 1 circuit if its double doors

Also if its just std surfac door contacts how close / inline are they? Are they decent ones? maybe a picture of how they are fitted.

 

As 6 says as you can now see fault finding is needed as all you know is its one of the 3 rather than identifying 1 contact.

However if its stable with 2 and unstable with 3 id suggest its local to the 3rd.

I presume as 6 its double pole and you havnt hidden resistors somewhere

I assume if enough cores then not enough zones left and don't want to buy an expander ?

Didn’t really want to get a expander for one door contact

how would I do the eol contact wiring

it is 6 core

would anything need doing in control panel

It's not just 1 contact tho, it's 3...

EOL will be wired different at the controls end.

 

Assuming this is three single doors, convert your 6-core into a data line for an expander adjacent to the first door, take single cables from the expander to each door.

Wire it however you want not sure if Orisec supports DP from an Exp. EOL would be better but you could have issues with stuffing 1/4W resistors in tiny old style contacts if your reusing them. Most would replace the contacts. Program panel accordingly.

This has the benefits of:- single fault will only take out one door, you can isolate doors individually, you know which door has an alarm or fault without taking the lot to bits, your cable to the sheds is a data line instead of DP so it's tampered in a better way.

2 hours ago, Mark52 said:

Didn’t really want to get a expander for one door contact

how would I do the eol contact wiring

it is 6 core

would anything need doing in control panel

if you have an additional 2 circuits where the 6 core goes back to (im assuming panel) then just use a pair for each contact (ie red/blk contact 1, blu/yell contact2 etc) and program the panel to the correct eol values.

Wiring should be in the manual but if not just say and ill dig out an image.

But also bear in mind how the contacts are installed. If there is an issue there however you wire them you will have problems.

Post a picture of the 3 with the door closed please