Are ballasts INDUCTIVE Loads

Bryan · #1 01-26-2003, 08:22 PM

Can anybody tell me if HID ballasts are considered inductive loads. The reason I ask is my timers have a rated capacity, but if the load is inductive the amount they can handle is less.

Why is this??.

reefburnaby · #2 01-27-2003, 07:07 AM

Hi,

Most electromagnetic (i.e. good old cap and core) are, for the most part, inductive in nature. The main issue is the startup surge. When the ballast is initially turned on, there is an initial rush of current that can be quite high. Larger the inductance, the larger the surge.

The problem lies in the relay or switch that lives inside the timer. When the relay or switch turns on, arcing occurs inside the switch. The larger the surge...the bigger the arc. The arc can be hot enough to melt the contacts on the switch - which means the switch can stay on or off permanently. This kind of problem can occur in all devices where directly AC switching occurs - like a heater.

Electronic ballasts are not as inductive. Hence, the inrush current is much smaller.

Hope that helps.

- Victor.

Bryan · #3 01-27-2003, 07:55 AM

Thanks Victor, makes sense. In my case I am using the HPS Son Agro ballasts and the startup current is 1.2 amps versus the operating amperage of 4.55. I think i am ok then, unless there is a huge spike at the moment of contact, but I don't think so as this is the function of the ignitor.