Outside Floodlight

[dunny]

Quite puzzled with an issue I am having with outside lights.

I have an isolation switch in my garage that is connected to my (old style) consumer unit with a 30a re-wireable fuse. In the isolation switch there are 3 20a fuses that previously fed 2 outside lights and took power to a shed. Before I moved in there was clearly an issue with the power going to the shed and one of the outside lights.

I don't need power to the shed and 1 of the outside lights was already disconnected (cable wa cut) so I stripped out the power to the shed and got rid. I checked all the connections for the 1 remaining outside light, replaced the fitting and successfully powered it up.

The other outside light had a cable that looked a bit perished and had no switch as it was directly powered from the isolation switch. Today I replaced the cable and the light fitting, and wired up a new fused switch so the light can be switched on from inside the garage. The light also has a separate sensor and so it will come on with movement but I wanted the switch so I could switch it off in the daytime.

Having wired everything up the light isn't working. I bypassed the sensor and I am getting power all the way to the light but it just doesn't come on. I have checked the bulb and it's fine. I even took the fitting down and wired it temporarily to some short flex and it worked. I tried a separate fitting that I know works and it still didn't work.

I have reached the end of my trouble shooting capabilities and wondered whether anyone had any suggestions. It's not critical and the entire electrics will get replaced in due course but I am baffled as to why the light won't work.

I thought maybe it was voltage drop or something like that but it's only over a short distance and the other lights over similar distances are fine.

Any ideas?

Thanks

D

 

[flameport]

I bypassed the sensor and I am getting power all the way to the light but it just doesn't come on.

Checked power with what? A proper 2 prong tester, or something which lights up when placed near a live wire?

Likely cause is the neutral is not connected.

 

[dunny]

I only have a basic tester, it is 2 prong but not a multimeter. There is current in both live and neutral at the light.....just no light!! That's why I thought that it may be a problem with low voltage.

I am going to connect it to the other use fuse terminal in the isolation switch this morning as I know this definitely works with the other light.

If that doesn't work I will give up, it's not that important.

Thanks

D

 

[bernardgreen]

There is current in both live and neutral at the light.....just no light!!

If there is current then where is it flowing to get from live to neutral ?

Do you mean there is voltage on both live and neutral ?

If live and neutral at the lamp are both at the same voltage then there is no voltage difference to drive current through the lamp.

At the lamp and with your two pronged tester measure voltage between earth and live. this should be about 230 volts when the switch is on. Then measure between earth and neutral, this should be zero or very close to zero. If this is not zero ( with the switch on and a bulb in the lamp ) then the neutral is not connected to the neutral in the fuse box.

 

[dunny]

Sorry, voltage, not current.

My tester can only test for voltage.

Thanks for the advice, it's looking like a neutral problem.

Regards

D

 

[dunny]

It was a problem with the neutral at the isolation switch. There was a little bridge bar from incoming neutral that was missing, found it in the bottom of the box.

All sorted now!!

Thanks for the pointers.

D