Volt drop causing flurescent to turn off??

[flyingsparks]

Hi, just installed a 6 foot Thorn flurescent light fitting in a workshop which is fed from a house near by. Now when ever the chopsaw is powered up (its only on a 13A plug) the flurescent turns off and then on again a second after once the saw is up to speed. Also the planer causes this to happen. The welder does not however even on full heat.

Could this be due to volt drop?? (I havn't calculated what volt drop I would be getting yet as I will need to go back to check length of run and cable size.)

What is confusing me is that the welder doesnt cause it to happen..,, unless its something to do with the inductive load of the motors on the planer and chopsaw??

All help will be greatly appreciated. Thank you!!

 

[RF Lighting]

Sounds like it to me.

What are the characteristics of the supply to the house, and also the submains to the garage?

 

[Lectrician]

Give us some rough distances and sizes

 

[flyingsparks]

It is a TT system in the house, feeding the workshop in I think from memory 16mm T+E (but could be 10mm), approximatly 20m of cable.

Would all flurescents do this, or could changing make or using an electronic one help??

 

[bernardgreen]

A couple of shorter fluorescents may stay alight better than 6 foot at low voltage.

BUT with moving machinery there should be incandescant lighting to prevent strobe effects making machinery look slow moving or stationary.

Or fit high frequency fluorescent fittings

 

[jujubean]

Hmmm
From what you say I dont think a voltage drop will be causing much of a problem. I mean the submain feeding the workshop seems plenty big enough for what you are using.
Why not simply try changing the fitting as fluorescents can be a bit "quirky" at times and what else you are using there shouldnt affect the light the way it is doing ..Unless perhaps the vibration of the saw is affecting maybe some loose connection within the fitting
Maybe another starter switch will help
Cheers
good luck

 

[flyingsparks]

I was a bit surprised too as the submain seems plenty big enough for what is in the workshop. Nothing else (appart from a few other pendant lights) was on while getting the problem. Could try another fitting I guess. Dont think its any connections and vibration as 'knocking' things around doesnt make it happen.
Thanks for your help..

 

[djrichie_t]

Its motor reactance that causes this, can cancel out the drive effect from the choke driving the fluorescent light. Quite a common one. Can easily be fixed by sticking a motor capacitor inline with either the feeds into the motor or into the light fitting. About 14 or 16uF upwards across your light fitting supply should do the trick as there is a wide tolerance to the value that can be used

 

[flyingsparks]

Ah right, yes makes sense! I will give that a go. Obviously I will make sure the capacitor is rated at 240V or more! Thanks very much!

 

[ricicle]

Ah right, yes makes sense! I will give that a go. Obviously I will make sure the capacitor is rated at 240V or more! Thanks very much!

I would go for at least a 400V rated capacitor due to the peak voltage of the sine wave and the transients from the motor.