Help,got a new led pir light,dont know where the white wire connects to ,confused.

hi need some help ,I purchased an led pir external light for my back garden,there was one up already but was very poor light,so took down old one and thought it would be just a matter of connecting the usual 3 wires to back of light,but on removing the old light from wall discovered the old light had an white wire coming from wall to the light as well as the usual blue green and brown wires,the new light has just the usual brown blue and green and brown,so my question is where does the white wire coming out of the wall where the old light was connect too,totally flummoxed here,i have installed lots or these sensors ,and never seen one with an extra white wire before, any help would be most appreciated from anyone out there ,thanks .

override switch line?

Thanks but what does override switch line mean ,where will the white wire connect to on the led light,thanks again.

extra live supply so you can switch light on by-passing PIR

The previous light presumably could be switched on permanently at a remote switch.

If your current light does not have a terminal for this then just terminate the core into a terminal block or push fit connector in the back of the light, then it will be available for the next light if required.

If you find the light does not work then the permanent line may be the white (odd colour) wire instead of the brown, but this could only be determined through testing.