Fluorescent Lighting multiplier

[Daibhid]

Hi all,

Can anyone tell me where I in the reg's, if anywhere it states whether a multiplier of 1.8 should be used for calculating the design current of fluorescent lighting loads?

 

[Brightspark2]

It doesnt...

The 1.8 figure is a rule of thumb for power factor on discharge lighting...

Get the actual ratings of the fittings for the design...

 

[Daibhid]

That's what I thought, thanks for the input...

 

[Welchyboy1]

Alot of new HF fluro fittings are alot less nowadays, the old fluros and other discharge lighting should still have this rough allowance

 

[D Skelton]

The 1.8 multiplier allows for when a number of capacitors within a circuit comprising of fluorescent luminaires eventually give up the ghost. Normally when a capacitor fails you would expect the power factor to drop to around 0.4 per fitting which essentially means that your bog standard 2x58W fitting shoots up to drawing an apparent power of around 300W instead of around 100W.

It is acceptable to design circuits comprising of fluorescent fittings without using a multiplier but unless you are either factoring in regular preventative maintenance of the installation or installing HF fittings or PFCUs then it would be prudent to use it.

A fundamental understanding of the science and principles of electrical installation would be able to tell you that your circuits should be designed to cope with the current being drawn. You don't need a regs book to tell you this.