strange fault

[wiganspark]

Basically got a 2 way con unit in a block of 4 flats, 1 x 6a mcb feeding lighting via timeclock,28w 2d fittings,wired in pyro and 1 x 16 mcb feeding a sw fused spur for the door entry system, new door entry was fitted last month and everytime the clock fires the lights up or knocks them off the door is opening,scratching my head with this, any ideas?

 

[trev]

Switched live from the clock going to the door entry via the lights maybe

 

[wiganspark]

that was my first thought but no completly seperate circuits

 

[trev]

Have you checked for a borrowed neutral? If there is one it could be wrongly terminated

 

[wiganspark]

just an old wylex con unit,3core and earth to timeclock then out to a pyro for lighting,door entry is just a 2.5mm to a switched fused spur next to cu,seems to be when one particular fitting strikes that its happening

 

[R G]

It seems to me that you have an under voltage situation , meaning that when the lights come on , causing a momentary low voltage situation , this in turn causes the doors to go to fail safe and open , the only way I can think off curing this is to try and re feed the communal door system to another supply or seperate consumer unit maybe ....

 

[DPG]

RFI maybe - emissions from lights switching on/off interfering with door entry controller? Daz

 

[Jase_82]

You could test rays theory fairly easily by switching the auto door off at the mcb and seeing if they open. Do the auto doors have motion sensors to make them open or similar? If so lighting can sometimes give false signals if there are too many reflective surfaces about. Clutching at straws tho...

 

[oldtimer]

Have you checked for loose connections back at the DB ?

 

[UNG]

Had similar problems with intruder alarms and access control kit in the past with 2D fittings on site solved it by using kit from this company bottom half of the products page has RFI and mains spike filters

 

[wiganspark]

thanks for your replies,ive tried connections all fine,no motion sensors on the doors just acces via fob or telecom entry from flat,im possitive that its happening when one particular fitting strikes, going to swap the fitting in the morning to see if it resolves it

 

[Tim]

Let us know how you get on, my moneys on rfi though.

Good luck,
Tim

 

[R G]

Ref the earlier reply ;
I think you will find it to be the 2d fittings when they strike both on and off , the also would happen with most fluorescent type fittings , that is why you find earh wires attached to RCDs , because off the momentary collapse on the circuit (loss of neutral) ......

 

[markythesparky]

i would think it would be something to do with the 2D fittings. fluorescent fittings generally 'leak' the earth very slightly, if you have a number of them this 'leak' will increase. try disconnecting the fittings and then let the timeclock switch the circuit as usual.