flourescent lighting

[karlspark20]

hi guys just wondering as my supervisor hasnt got time 2 explain things to me in detail, i recently installed 12 5ft dual(two tubes, 58w) flourescent lights in an industrail refrigerator an out of interest measured the current it was pulling and it was 9.3A why is this so high, any feedback greatly appreciated. karlspark20

 

[MarcT]

Are these switch start fittings? I would say that power factor would be a big issue here although 30% losses does seem a little excessive.

 

[karlspark20]

yes they are switch start fittings am i correct in saying that all flourescent lighting circuits need 2 be multiplied by 1.8 if so the circuit current would be this i.e 24 lamps x 58w x 1.8/ 230v = 10.89A

 

[MarcT]

yes, that's the same for all discharge fittings unless the power factor is given, then you can be more precise. HF ballasts operate on a much leaner factor, in some cases unity.