Pir Sensor With Some Strange Wiring

[electrics_new]

I came across a PIR sensor today.  Looks pretty old but customers says it works and disconnected lights on front of property due to having the property painted.

They would now like new lights putting into the existing wiring.

x3 lights

Point A: twin and earth (easy this is the last point in the circuit)

Point B x 2 twin and earth easy power comes in and power goes out)

Point C:  OK this is the strange one.  Twin and earth which supply point B.  Then x2 neutrals and one live.  However, i get 230v between the neutrals.  The light that needs to be fitted is a simple L, N and Earth connection. What do I with two neutrals showing 230v across them and a live showing zero volts.  I understand the PIR sensor would be activated and provide live - how do I wire up the existing circuit ????

PIR sensor is located out of reach............... I can go back when it's dark take a reading.......... but any ideas ????

Thanks

 

[m4tty]

230v between the neutrals ? one of them isnt neutral

 

[Andy™]

voltages with reference to what. and if you really hav 2 neutrls, and one is live, its probably because something is now open circuit. connect together and something will then work. FIR required before joining them though

 

[electrics_new]

i understand that so how do I wire it ????

 

[ProDave]

Do some continuity readings to find out where they go.

Just because they happen to be black (or blue) does not meant they are "neutrals"

It might be some hair brain unconventional overide circuit?

None of us can guess what's been done before.

 

[electrics_new]

Issue is Pro Dave they go into the rending and then into a box tricks............. that I can't see.

If it helps there is:

M S L N E written on the box of tricks.

 

[steptoe]

more testing required

MSLNE

at a guess

mains

switched

live

neutral

earth

but that could be total hokum   :C

 

[ProDave]

I think a photo is needed.

 

[electrics_new]

StepToe,

There is almost no volts between any of the MSLE in fact I got 12 volts reading.

Can't remember between which !

PRO DAVE - i'll get a photo in the morning and post it tomorrow eve.

 

[steptoe]

so,

do you have access to this box or not?

and, what are you measuring with? and in reference to what?

 

[Andy™]

GJD PIR system?

 

[electrics_new]

got access to the box and will take some pics and post.

 

[steptoe]

Issue is Pro Dave they go into the rending and then into a box tricks............. that I can't see.

If it helps there is:

M S L N E written on the box of tricks.

got access to the box and will take some pics and post.

:shakehead

 

[Andy™]

:shakehead

thought that myself.. no access but he knows what the terminals are marked as?

 

[SLIPSHOD & SLAPDASH]

I recon its the black of a tw&e thats a switchline, not a neutral.

 

[kerching]

Doesn't the GJD system have a burglar alarm type control cable to it?....or am I thinking of something else

 

[Andy™]

Doesn't the GJD system have a burglar alarm type control cable to it?....or am I thinking of something else

usually does between sensors & control box, but it could have been done in T&E, which would give him 12v if he's testing at the sensors

 

[kerching]

Good point

I will go and find my overcoat