Voltage Outputs and Number of Ballasts

Has it something to do with the harmonics passed on from the out put to the ballasts ? they are inductive ballasts?

All that I know is that these ballast are HID not regular 0-10VDC electronic ballasts. And I have never tested such ballasts. I'm not familiar with them. With regular ballasts, the output voltage will stay constant at ~0.25V , no matter how many ballast wired on the same output.

Hello.

Maybe 5.438V is there on the output to compensate for the voltage drop on the lines to each of the 40 balasts (and if you measured directly at every balast it may have the usual 0.2V)?

It sounds like your analog card is producing a voltage source and the input circuitry for your ballasts is actually current sensitive. Without having any documentation about either unit nor how these units are wired and configured, that's the best I can offer.

Where are you measuring this voltage?At the source, or at the ballasts?Do the lamps respond properly?

Need more info to help.

Have you contacted Douglas or Metrolight to ask if your controllers are compatible with your ballasts?

Data on the controller says it can drive up to 50 ballasts per output, as long as the control input of the ballast conforms to a certain standard. Here's a quote from their product data sheet:

"The ALC3-BCM-12 is designed to control electronic

dimming ballasts that utilize the 0-10V control

method. This includes all types of ballasts that use

the same control method as the Phillips/Advance

Mark VII dimming ballast."

So the question is, do the ballasts use the same control method as referenced in the controller data?

Seems to me the controller and ballasts are not compatible, at least not up to the number of ballasts the customer is trying to parallel.

Tom