Power Consumption Question

Hello i am relatively new to growing and have three plants that are two months old, under a 400w dual spectrum using a 600w ballast.


My partner was having a moan about how much of an increase we will get in the electricity bill, I told her not to worry it's only 400w (slightly less that most peoples PC uses)... But in truth i am not exactly sure how it works ...Does the ballast draw the full 600w from the mains or just the 400w required to power the bulb. I have no clue when it comes to electrics but it seems logical to me that the only power drawn is just enough to power the bulb otherwise where would the other 200w go?.

Anyway as silly as the question may seem i thought i would ask anyway for piece of mind.

cheers, KickMuck

It will pull alot more than a computer. Why not offer to pay her however much it goes up?

My PC has a 750w PSU in order to power my needy powerful gaming GFX card, Most PCs use an average of 400-450w, .. the money is not an issue ..she moans at everything I'm merely curious as to whether my ballast is drawing 400w or 600w for a 400w bulb

I'm using a 400 watt ballast with a 400 watt MH bulb. I also have a 750 watt gaming PC that I used to run at least 20+ hours a day. I've only been running the lights for a few months at 18 hours on and 6 hours off and my electric bill was higher than it ever was. It was usually around 125 and it hit 180ish this month. And this is without the use of my PC at all. I had to make that sacrifice.

TreeGod said:

I'm using a 400 watt ballast with a 400 watt MH bulb. I also have a 750 watt gaming PC that I used to run at least 20+ hours a day. I've only been running the lights for a few months at 18 hours on and 6 hours off and my electric bill was higher than it ever was. It was usually around 125 and it hit 180ish this month. And this is without the use of my PC at all. I had to make that sacrifice.

Click to expand...

I suppose this helps to answer my question. Whilst the PC is on and idle or we are just browsing internet...Its not really using its full power consumption as to when the gfx card is whirring away playing Planetside 2 or Crysis(unless you was a hardcore gamer that played for 18 hours solid every day).

I think its fair to assume that the 600w ballast is only drawing the 400w needed to power the bulb. Unless anyone knows better.

Cheers

I probably played 8-10 hours total a day whilst spending the other time browsing and listenin to music or just on idle. But I was still surprised to find my bill was higher. I thought it would be the same if not lower since the ballast was lower than my PC PSU and not on as often.

a 600w ballast will draw 600w.even if it only needs 400w

Hmmm. It doesn't make sense to me that a 750w PSU will constantly draw 750w while pc is idle, why would it? The need for the 750w PSU was because my GFx card required a minimum of 400w to power the card alone, split the rest with the power it takes to power the motherboard, processor, fans, disc drives etc. I had the same motherboard with a previous 550w PSU but needed to upgrade to 750w with my new card, so the GFX + other components has sufficient power supply to power the whole lot together.

I dont see how it is much different using a ballast to power a bulb. I could use a 1000w ballast to power a 200w bulb, but why would it consume the whole 1000w to power just 200w.

It Just don't make sense to me ..then again I'm sure i have a lot to learn.

pc psu ; is going to use burst to 750w (and there is no sign or evidence you are pulling 750w. GPU needs 400w (just to power it) but that is spec'ed so it can utilize up to 400w . think of it like reserving wattage, they set the minimum spec to be what they feel the most consumption will be. go to walmart and buy a power consumption plug that sits between you and pc and you will see what I mean. The point is likening that to a light bulb is not a relevant comparison. The ballast will draw 600w when it draws, it will fill its capacitors even though there is only a 400w bulb attached to it; it will draw at 600w but not consume 600w*20hrs it will consume 400w as it is not drawing constantly (like a regulator) . The light is drawing 400w 20 hours a day, I could almost guarantee you your pc for those 18 hours is truly only utilizing (on average) 250-300w /hr and closer to 150 when at rest ; this would mean with the gimp math we are using here that your bulb is going to consume 33percent more power than your pc for 18 hours a day and up to approx 200 percent more for the remaining. so if your light is 20/4 , or 18/6 well you do the math. seriously invest in an electric meter that plugs into wall outlets, it will show you a lot if you are curious (my wife stopped asking me those questions when we rated her blow dryer, curling iron, and flat iron as she was getting ready for the day.....) I hope this helps a bit

So am i right in thinking about the pc utilization of power?

This is different to to the use of a bulb drawing a constant power, and the 200w difference from the 600w to 400w is stored in the ballast capacitors? If this is the case then would this not burn out the capacitors in the ballast faster than usual?

Still quite confused. Trying to understand.

Be patient with me

no but you will probably burn your light quicker a ballast can not be use to a comparision with a psu..... that's like your kettle and washing machine....and not probably burn out your light quicker you will.......

It seems to be coming to the ultimate question to myself here ..

Buy a 400w ballast vs the electricity bill difference?

or 600w bulb he he the real question is ...does a 600 w produce a big enough yield , to offset the extra cost?

Don't fuck around with the 400, use 600. Explain to your partner you will cover the increased $50 per month so that you can grow $2500 worth of weed.
Trust me, the math works out as long as you have grow skills. Your weed will pay for your electricity 10 times over.

First, a computer power supply is rated *maximum* 450-700w... what you're using is no where near that, unless you're running a dozen spinning hard disks and a whole bunch of other additional peripherals.

Buy a 600w electronic ballast with 600w lights, and ensure your ballast is dimmable 75% and 50% if you don't like the bill, or if you want to start low and up it later.

A 400w can't go up to 600 if you're not happy with your grow, but many electronic 600w can go down to 300w and 450w

-spek

djxtreme said:

a 600w ballast will draw 600w.even if it only needs 400w

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The bulb will draw 400w from the ballast weather the ballast is rated at 400w 600w or 1000w

the amount of power/watts is dependent on voltage V and current I in turn the amount of current I is dependent on R resistance of the bulb
the voltage supply of a 400w 600w and 1000w are the same, the power increase comes from an increase in current flow I

a 600w bulb has a lower resistance than a 400w bulb, this allows more current to flow allowing a higher wattage at the same supply voltage

the ballast rating is the maximum power it can supply you can use any bulb wattage as long as the bulb wattage does not exceed the rated wattage of the ballast
a 1000w ballast will run all bulbs from 1000w and below a 600w ballast will run all bulbs from 600w and below

a 1000w bulb in a 600w ballast the low resistance of the 1000w bulb would attempt to draw so much current enough for (1000w) from the 600w supply it would blow its fuse if it has one or it would burn it out

a 400w bulb into a 1000w ballast the high resistence of the 400w bulb only allows enough current for 400w to flow, which the 1000w ballast can easy handle

peace

I should of added that I pay the bills anyway 'hehe'... But to be honest I am gonna keep it as it is for this grow..The plants are not complaining

For future reference though i think i will use a 400w Ballast on a 400w bulb or maybe a 600w ballast on a 600w bulb. Seems a bit like overkill for me to use 600w for three plants. I like to keep it small, just 3 plants for personal use, with the execptoin of giving some away to friends and family as a gift.

600 will give you more bang for the buck and better buds. So you grow a crop, and then not have to grow for a year. See, it saves electricity

Easy to grow a lot of weed... so hard to grow just a little.

skunkd0c said:

The bulb will draw 400w from the ballast weather the ballast is rated at 400w 600w or 1000w

the amount of power/watts is dependent on voltage V and current I in turn the amount of current I is dependent on R resistance of the bulb
the voltage supply of a 400w 600w and 1000w are the same, the power increase comes from an increase in current flow I

a 600w bulb has a lower resistance than a 400w bulb, this allows more current to flow allowing a higher wattage at the same supply voltage

the ballast rating is the maximum power it can supply you can use any bulb wattage as long as the bulb wattage does not exceed the rated wattage of the ballast
a 1000w ballast will run all bulbs from 1000w and below a 600w ballast will run all bulbs from 600w and below

a 1000w bulb in a 600w ballast the low resistance of the 1000w bulb would attempt to draw so much current enough for (1000w) from the 600w supply it would blow its fuse if it has one or it would burn it out

a 400w bulb into a 1000w ballast the high resistence of the 400w bulb only allows enough current for 400w to flow, which the 1000w ballast can easy handle

peace

Click to expand...

^^ what she said. Fact.

Look at it as the 'pull' of each item (in this case a 400w bulb) as the absolute maximum current that will be 'sucked' through a circuit. If you have a circuit that is 15 Amps capable (traditional household circuit), but you only have a single 100w bulb plugged in, you're not pulling all 15A... you're only pulling what the bulb wants/needs: 120v / 100w = 1.2A.

Always see things as your bulbs 'pull' amperage when looking at your ratings. Devices only take what they need. That is why a 500w computer power supply almost never uses this capacity; electricity is drawn through it by the resources that require it... the power supply doesn't use the electricity or even 'see' the electricity unless the devices behind it 'ask' for it.

-spek

ps. hope this made sense. I"m a bit drunk and in the middle of garden duty

Well, if I wanted to know what the exact amp draw of my light/balast I would go to the UL label on it...
Every UL approved part has a name plate rating... It is UL approved isn't it?
Anyway, the only true way to find out what the draw is to put an Amp Probe on the hot lead and read it..while it is running at full....
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Good Luck....