door magnets and fire alarm panel

[paul copeman]

hi everyone

i was sent to a job in a nursing home by my company today where the door latch is magneticly operated and opened from the office by a button on the phone after the intercom has been pressed

the problem was the door has stopped working and is always stuck in the locked position so they have to leave it open all the time

i checked the supply at the latch and all associated connections at the door and found no power

the thing is tat as there is no power shouldnt the latch ne in the be unlocked position for safety reasons i.e fire escape

i have located the fire panel and associated enclosure with all the transformer and 12v telephone cables but can anyone point me in the right direction as to how to go about finding out what is wrong with the supply to this door

all the other doors work as they should

many thanks

 

[NozSpark]

From the sounds of it this has absolutley nothing to do with the fire alarm.

It sounds like a door intercom with a remote opening latch

 

[Andy™]

hi everyonei was sent to a job in a nursing home by my company today where the door latch is magneticly operated and opened from the office by a button on the phone after the intercom has been pressed

the problem was the door has stopped working and is always stuck in the locked position so they have to leave it open all the time

i checked the supply at the latch and all associated connections at the door and found no power

the thing is tat as there is no power shouldnt the latch ne in the be unlocked position for safety reasons i.e fire escape

i have located the fire panel and associated enclosure with all the transformer and 12v telephone cables but can anyone point me in the right direction as to how to go about finding out what is wrong with the supply to this door

all the other doors work as they should

many thanks

you can get fail close and fail open. applying power does the opposite. so in your case, there will be no power at latch unless 'open' button is pressed

unless the door can be opened from the inside (i.e handle), then there would usually be a green 'break to open' point near the door

as above, it probably has nothing to do with the fire alarm panel. why would it?

and i would start by checking the fuse & power supply, then connections at both ends

 

[paul copeman]

thats what i thought mate but my boss semms to think not

ny came and changed the intercom and ever since then the door latch doesnt work

i took the inter com off the wall and behind it there was three phone cables with all the strands comming out into a big bundle

basically after untangling eberything i found one of the cables had a yello and white was attached to the intercom and the black and red have about 24v between them

on another set of strands the black and red had 24v

on the last set no voltage at black and red

there was a connection box with door contactor written onit but inside only two wire going to a connection block nothing coming out the other end

i also noticed thatnone of the three cables behind the intercom were leading to the door latch

confused

i am

 

[Andy™]

latch is probably connected to the external call button

 

[paul copeman]

hi andy there is a panel u have to enter a code to get out

this flashes green when corrct code is entered but doesnt activate door latch

i checked power at door but cannot phathom where to find suupply fuse etc the breakers are all on none tripped ect

maybe there is a cartridge fuse in somewhere in a fcu i havent spotted

 

[Andy™]

probably 20x5 glass fuse inside the PSU, but if the keypad has power, then the latch should (normally same supply).

it could also be the relay controlling the latch has failed

 

[paul copeman]

i dont wanna sound really stupid but whats a PSU and where would the relay be

---------- Post Auto-Merged at 22:54 ---------- Previous post was made at 22:37 ----------

k would have thought the cable with the two cores connnectedtothe intercom (that rings the phone in the office) would have a signal going back from the phone to activate/deactivate the door magnet when the button is pressed

the thing that got me is that none of the three cablesbehind thye intercom are belling out to the door latch so the cable there is comin from somewhere else

 

[steptoe]

find which cable on the office phone opens the latch,

then work from there back.!

or get an electrician in, cos it seems your boss doesnt have a clue either,

he goes in,

Fs it up,

then sends you in to fix it,

and no offence,

but you dont know that much either.