Ballast amps vs wattage

[Tab28]

I had to replace my galaxy dual 250 ballast. I now have 2 selectable wattage ballasts. I have both at 250. My apex has gone down 1.5 amps with 2 units even though the watts are the same as the single dual.

Does gallaxy run higher watts than the stated 250?

 

[TaylorPilot]

That seems like a big drop. What was the amperage draw before you replaced the ballasts. at 120V that is 180 watts less than before for a system that should be outputting 500-550

 

[twilliard]

I would say that drop points to efficiency of the new ballast

 

[Tab28]

Apex does not separate per outlet. Only the total draw. The total draw with dual ballast was 1.5 higher. Will a 250 bulb fire if the watts output is actually lower?

 

[twilliard]

It will fire as the starting voltage is high.

 

[TaylorPilot]

It would help if we knew the total input, not just the difference.

 

[redfishbluefish]

I'm going to take a shot at this, if I understand this question correctly.

I'm assuming this is a single phase AC ballast running at 110 V.

What is commonly talked about is V x I = W....that is Volts x Amps = Watts. However, what is left out of this simply formula, when talking AC volts, if "power factor". Think of this as volts lost or dissapated and not involved in the work. I'm going to guess that this power factor was different from the old dual ballast versus the newer two single ballasts. I hope this makes some sense. Here's the actual formula for AC:

I(A) = P(W) / (PF × V(V) )

I = Current in amps
P= Power in watts
PF = Power Factor (a number less than 1)
V = Voltage in volts.

 

[Tab28]

It would help if we knew the total input, not just the difference.

Not sure how accurate it would be. But took to amp difference before ballast turned in and after it was on. The old dual ballast pulled about 5.1 amps. The 2 single ballast pull about 3.6 amps. Not sure how accurate apex is but using the above the dual was pushing 561 and the 2-singles are pushing 396.

Guess I should get a volt meter. Never used one for a ballast before. Not sure how to either.

 

[jedimasterben]

This is what you want. http://www.amazon.com/P3-P4400-Elec...F8&qid=1462993102&sr=8-1&keywords=kill+a+watt

 

[Tab28]

Kill a watt device would be easier. My mind a first thought went to voltage tester. Thinking how to connect the two terminals on a ballast. Not even thinking of the easier thing.

 

[AZDesertRat]

You can get Kill A Watt meters locally at Lowes and Home Depot too. I have two and use them all the time on new or different appliances and pieces of equipment. They were a great tool when I started making our home more efficient.

 

[Tab28]

Well i used the a kill a watt. And the fixture that seemed to be a bit too blue, radium bulbs, is only pushing 128 watts. The other ballast is pushing out what it should be.