# HPS power question



## SPEARCHUCKER (Aug 22, 2011)

Looking to expand my grow cab some. Was reading around some places as to how much wattage these lights use.
Says a 150 runs at 200w. And a 250 runs at 300w. 
Is that true or is that just the initial firing wattage?

Also found this neat calculating site for lights. 
hxxp://www.hydroponics.net/learn/hid_lamp_op_cost.asp
Though Im guessing it might be 50w off on everything if it takes an extra 50 to power an HPS over whats listed.


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## Growdude (Aug 22, 2011)

All HID lights use more than the bulb wattage, electronic ballasts not so much.


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## SPEARCHUCKER (Aug 22, 2011)

Thanks Growdude. But really not following. Im usually playing with LEDs and things.

So your saying to look for one with electronic ballast and it might use a little more power, but not 50 whole watts worth?
Cause instead of like a 150hps putting out 16k lumens. Might as well just spend 12 bucks on a bulk box of cfls. 9-24w bulbs would hit 15750 lumens and save 60 bucks.


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## Growdude (Aug 23, 2011)

SPEARCHUCKER said:
			
		

> Thanks Growdude. But really not following. Im usually playing with LEDs and things.
> 
> So your saying to look for one with electronic ballast and it might use a little more power, but not 50 whole watts worth?
> Cause instead of like a 150hps putting out 16k lumens. Might as well just spend 12 bucks on a bulk box of cfls. 9-24w bulbs would hit 15750 lumens and save 60 bucks.


 
You need almost 10, 23 watt cfl's to match lumens. so you need alot of sockets and cords as well.

even if you could buy that many cfls with $12.00 the added bud you will get over cfl's is going to make up for $60.00.

What size room are you going to be using, that 150 is only good for 3/sq ft


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## Roddy (Aug 23, 2011)

HPS....superior over all other budding options.


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## SPEARCHUCKER (Aug 23, 2011)

Well I only added about 3sq to the end of my grow space. And need to cover that space, the rest is fine.

From THG on their 250 digital it says in the description.
"The soft-start technology allows for 50% less power consumption during lamp start up."
So does it use 300w to power it on, then settles back on the wattage used after. Or does it continuously use 300w to muscle it all day?
And dont just mean for digital, but magnetic ballast as well.


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## The Hemp Goddess (Aug 23, 2011)

SPEARCHUCKER said:
			
		

> Thanks Growdude. But really not following. Im usually playing with LEDs and things.
> 
> So your saying to look for one with electronic ballast and it might use a little more power, but not 50 whole watts worth?
> Cause instead of like a 150hps putting out 16k lumens. Might as well just spend 12 bucks on a bulk box of cfls. 9-24w bulbs would hit 15750 lumens and save 60 bucks.



To determine the watts that something uses, take the amps times the voltage.  It was my understanding (and correct me if I am wrong) that *all* fixtures that use a ballast take more energy than the stated wattage on the bulb.  This included floros.  I cannot find any amperage on any floros right now.....

Where did you find CFLs that put out 72 lumens per watt?


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## SPEARCHUCKER (Aug 23, 2011)

Cant recall where. But on side the box it says 24w- 1750 lumens.
My bad. Just looked, says 1650 lumens. Should be 14850.

I figured it would take power to run a ballast. But not 50w worth.
And I dont know the amps of a ballast. Never seen one to look, and dont see anywhere that has those numbers.

But thanks for that equation THG. Will come in handy for alot of things.


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## Locked (Aug 23, 2011)

Maybe somebody who runs a HPS also has one of those meters you can buy at Home Depot that measure power being used?  Wld be nice info to hve.


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## Classic (Aug 23, 2011)

You need to know your ballast efficiency (power out/power in) to determine the electrical usage.  All ballasts are not created equally.  I did a little research (Google "HID ballast efficiency").

Efficiencies vary but a standard magnetic ballast can be expected to be in the 80-85% range.  So, for a 250 w HPS, the ballast loss is somewhere between 44 and 60 watts.

A high efficient electronic ballast can be in the 90-93% range.  For 250 w HPS, this is 18 to 27 watts.

These are rough efficiency numbers but should give a decent indication of ballast energy usage.  Obviously, you can spend more (or less) money buying more (or less) efficient ballasts.


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## Growdude (Aug 23, 2011)

Nice Classic


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## mrcane (Sep 4, 2011)

You can always check your circuit for the amount of amps. that is drawing off it. With a simple amp meter..


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