How 2 Calc Power Factor for MANYYY 150w HPS

[angryelf]

Hello all,

I also posted this in the MicroGrow area as well, sorry if that's not allowed but I really want to find an answer.

Any electrical gurus know how to safely calculate the power factor requirement for multiple 150w econolight style lights (150w HPS , without built in capacitor)?

I want to add a capacitor or plural to each circuit as required to drop the amperage requirement.

My goal is to string together (7) 150w HPS on a 20 amp circuit.

I will run 3 of these circuits for a total of 21 lights.

Problem is these lights DO Not come with a capacitor and therefor draw lots of amps, relative to their size.

I figure with the correctly sized capacitor I may be able to drop my amp requirement almost in half.

I've read the past threads on adding a capacitor to a single light but nothing on multiple 150's?

Why would anyone want to do this u ask?

Well I have a large space with limited ceiling height, about 40". Add in airspace for safety, a reflector above, media below and I'm about out of room.

My idea is to go vertical with lots of lights close together taking advantage of the lighting overlap.

I could use fewer but larger bulbs but I already have the 150's at my disposal and for the price I'm curious to see how the " many smaller bulbs are better then a few bigger bulbs" argument holds water.

Thoughts?

 

[Hydro-Soil]

Hello all,

I also posted this in the MicroGrow area as well, sorry if that's not allowed but I really want to find an answer.

Any electrical gurus know how to safely calculate the power factor requirement for multiple 150w econolight style lights (150w HPS , without built in capacitor)?

I want to add a capacitor or plural to each circuit as required to drop the amperage requirement.

My goal is to string together (7) 150w HPS on a 20 amp circuit.

I will run 3 of these circuits for a total of 21 lights.

Problem is these lights DO Not come with a capacitor and therefor draw lots of amps, relative to their size.

I figure with the correctly sized capacitor I may be able to drop my amp requirement almost in half.

I've read the past threads on adding a capacitor to a single light but nothing on multiple 150's?

Why would anyone want to do this u ask?

Well I have a large space with limited ceiling height, about 40". Add in airspace for safety, a reflector above, media below and I'm about out of room.

My idea is to go vertical with lots of lights close together taking advantage of the lighting overlap.

I could use fewer but larger bulbs but I already have the 150's at my disposal and for the price I'm curious to see how the " many smaller bulbs are better then a few bigger bulbs" argument holds water.

Thoughts?

Get high quality ballasts. Even then you're not going to be able to use anywhere near that many lamps.

If you look around you can find a thread where someone took the trouble of testing exactly how much power different ballasts draw.

An econo 'type' ballast that was a few months old and running with an old bulb was sucking up nearly 500watts. This was a 150w hps.


I would look into building multiple separate units and making sure you didn't have more than 2 cabs on any one circuit in your house.

 

[angryelf]

Hey HS,

I guess I should clarify.

I believe the biggest factor in reduction of amps or watts ( we can calc it either way) is the addition of the capacitor, not the quality of the ballast.

Although in a round about way your are correct because generally speaking the higher priced fixtures already include a capacitor.

At this point its kind of a "see if I can do it project".
Of course I could pony up and buy
-12 250w
-8 400w
-5 600w
= to roughly equal to 21 (150w)

but that would cost way more...

I can get the 150w HPS pendant fixtures for $20 each.

$20 x 21 units = $420 go figure... no pun intended or calculated just works out this way. Add in a few bucks for the correct capacitor and off we go.

From what I've read here others have been able to drop the amp draw down to less then 2 amps per light with a cap.

2amps x 120v = 240w give or take

20 amp circuit x 80% for safety = 16amps

16 amps x 120v = 1920w available

1920w / 240w / per light = 8 bulbs per circuit

I'm only planning on 7 per circuit, adds a little headroom for inefficiencies

 

[Hydro-Soil]

Hey HS,

I guess I should clarify.

I believe the biggest factor in reduction of amps or watts ( we can calc it either way) is the addition of the capacitor, not the quality of the ballast.

Although in a round about way your are correct because generally speaking the higher priced fixtures already include a capacitor.

At this point its kind of a "see if I can do it project".
Of course I could pony up and buy
-12 250w
-8 400w
-5 600w
= to roughly equal to 21 (150w)

but that would cost way more...

I can get the 150w HPS pendant fixtures for $20 each.

$20 x 21 units = $420 go figure... no pun intended or calculated just works out this way. Add in a few bucks for the correct capacitor and off we go.

From what I've read here others have been able to drop the amp draw down to less then 2 amps per light with a cap.

2amps x 120v = 240w give or take

20 amp circuit x 80% for safety = 16amps

16 amps x 120v = 1920w available

1920w / 240w / per light = 8 bulbs per circuit

I'm only planning on 7 per circuit, adds a little headroom for inefficiencies

You're throwing your money away on those $20 lamps. Who cares what the amps are if you're drawing (and paying) for twice the wattage it's putting out, every time you use it.

Start small. Buy quality. Build to your comfortable level. You'll spend less money in the long run and have fewer hassles to deal with.

If you don't see the value in that, there's nothing I can say that will help you.

 

[Dr420CloneX]

I agree with hydro -soil. 5 600 watters is pretty big. For about 500 for a full 1000 watt setup you could yield 2-3 lbs under that thing. get 2 good 1000 watters and the yeild will pay for the lights themselves at harvest time. Happy growing.

 

[Barnt]

I use one of those e-conolight 150w ballasts and everything you have said is 100% correct, don't let anyone tell you that those ballasts are crap because of how many watts/amps they pull.

For those that don't quite know whats going on, these ballasts use more amps, as in more current flows THROUGH them. They do not however use as many watts as amps they pull. The reason for this is because they feed back amperage back into the circuit, however it is OUT OF PHASE. A capacitor fixes this phase shift and thus prevents the excess current draw and flow through of current.

In large industries with heavy motors/coils they have to make sure their power factor (how much their usage is out of phase) is near 100% because the power company does not like out of phase current being put back into the grid.


Before knowing this, I wanted to get a cap thinking that my ballast was using extra watts and thus costing more. However after learning that it just pulls more amps (you can't plug as much stuff into a socket) and the watts were the same, I left it alone.

What I did was found a 150w ballast that came with a capacitor and then read the rating. I think it was something around 47uF but I really don't remember. I just remember that it was pretty big. Good luck in your search!

 

[Hydro-Soil]

I use one of those e-conolight 150w ballasts and everything you have said is 100% correct, don't let anyone tell you that those ballasts are crap because of how many watts/amps they pull.

Over time your ballast will run hotter and hotter. How hot does it run now?
That's wasted watts that you're paying for. Forget Amperage for right now.

The other thing you're not thinking about is how much heat each individual lamp puts out.

The 150w is MOST effective out to about 9.5 inches. (believe me, I've done the research and used to scrog with them) Compare the number of lumens you'll get from a 400w HPS or CMH to the equivalent number of 150w lamps and you'll notice that your heat is much higher with the multiple 150's.

Have you grown cannabis before? If not, I'd seriously recommend you start with 1, 150w or maybe a 250w CMH.


If you want to see the 'Many bulbs is better than one' run with CFLs. Otherwise you're going to spend double on ventilation and odor-control if you go with multiple HID lamps.

 

[sparkjumper]

I couldn't agree more 250W is where you want to start from,if you want to smart that small.Get quality fixtures and use nameplate amperage ratings to size the wire forget volts and watts

 

[angryelf]

Ok Guys, thanks for the responses so far, although none have directly addressed the posted question.

Not to be flip but...this isn't my first rodeo.

I'm simply exploring a different avenue, think of it as an experiment , or gambling if you will without spending a dime of your own cash.

I'm not asking which light is best, which ballast is best or what size bulb should I use or how to grow.

The question is how to correct for power factor inefficiency across may ballasts on the same circuit?

Keep in mind my vertical space is extremely limited <40"max with low points of 32", but the overall horizontal space is greater then 14' x20' ,

So, 1000w bulbs are not conducive to my application.

I require lots of light spread out over a large area.

HS, thanks for responses but you're a little off on a 150w using close to 400w watts of electricity. Yes you are correct the "draw" maybe close to that amount but as a residential customer you are not billed at that rate. Residential customers are billed on Kilowatts / hour not KVA-hour usage.

Example:

If a 150w is drawing 400w but only using 180w for the actual load (bulb & ballast) the unused power ( 400 - 180) = 220w is returned thru the neutral line back to the power source out of phase. Your are not charged for the returned 220w but your circuits must still be capable of carrying the load. This is why correcting the power factor is so important.

For residential use this isn't a big problem except that it makes an extremely inefficient way of power distribution. Electric co does consider low power factor or ( out of phase power) a problem for large commercial customers, and charges accordingly.

When the power factor is low you need more amps, larger breakers, and wire to compensate for the inefficiency.

Alternatively we can up the power factor but correcting the power factor with a correctly sized capacitor(s).

Thereby reducing, total power requirements and possibly reducing wire size, breaker size and adding more loads per circuit, in this case, 7 bulbs per circuit instead of 3.

Any commercial electricians / electrical engineers that can answer this?

Thanks to everyone who has taken time to try and help.

-AE