A Bored Electrician to Answer Your Questions

chrisg420 said:

Quick question. my friends a electrician and he was saying something about if i wire my ballasts for 240 and he runs me a outlet for 240, and i rewired my ballasts that i could run 2 400 watt lights for the price of one? is this true?

Click to expand...

kinda, but not really, lol...

the reason being is that you get billed for wattage from the power company. wattage remains the same regardless of voltage. increasing the voltage reduces the amount of amps used, but the watts always remain the same... ill demonstrate:
so you have 2 400w fixtures... with the ballasts they will draw aprox. 440w (the 40 watts being the heat generated by the ballast) that is a total of 880w
880w= 7.33amps @ 120v
880w= 3.66 amps @ 240v
880w= 73.33amps @ 12v
but what does this mean?
it means that the higher the voltage, the less amperage, which means 2 things-
1- you can add more fixtures to the circuit safely, as your wiring, breakers, and outlets are rated for amperage.
2- because of the higher voltage, the components inside your ballast will operate at a slightly higher effinciency, roughly 10%, therefore generating slightly less heat, which in turn will slightly reduce your electric bill, but not by very much, with your setup you would save roughly .08 kwh, which is only a marginal savings.
however because this gain is expressed as less heat being generated, there is also less heat to be dissapated, therefore you would also notice a slight reduction in cooling costs as well, but nothing to write home about...
basically increasing your voltage is a great idea if your trying to get max lighting out of your electrical system, but as far as savings on the bill, with what your running, i wouldnt expect to see more than a 10$ reduction in the bill per month, if that.
so in a nutshell, its not a bad idea at all, but as far as runing two lights for the cost of one, well if that was the case everyone and there brother would be doing it, dont you think?

ps-
i also would like to add that your startup and restrike time would also be reduced with 240 vs 120.....

IAm5toned said:

kinda, but not really, lol...

the reason being is that you get billed for wattage from the power company. wattage remains the same regardless of voltage. increasing the voltage reduces the amount of amps used, but the watts always remain the same... ill demonstrate:
so you have 2 400w fixtures... with the ballasts they will draw aprox. 440w (the 40 watts being the heat generated by the ballast) that is a total of 880w
880w= 7.33amps @ 120v
880w= 3.66 amps @ 240v
880w= 73.33amps @ 12v
but what does this mean?
it means that the higher the voltage, the less amperage, which means 2 things-
1- you can add more fixtures to the circuit safely, as your wiring, breakers, and outlets are rated for amperage.
2- because of the higher voltage, the components inside your ballast will operate at a slightly higher effinciency, roughly 10%, therefore generating slightly less heat, which in turn will slightly reduce your electric bill, but not by very much, with your setup you would save roughly .08 kwh, which is only a marginal savings.
however because this gain is expressed as less heat being generated, there is also less heat to be dissapated, therefore you would also notice a slight reduction in cooling costs as well, but nothing to write home about...
basically increasing your voltage is a great idea if your trying to get max lighting out of your electrical system, but as far as savings on the bill, with what your running, i wouldnt expect to see more than a 10$ reduction in the bill per month, if that.
so in a nutshell, its not a bad idea at all, but as far as runing two lights for the cost of one, well if that was the case everyone and there brother would be doing it, dont you think?

ps-
i also would like to add that your startup and restrike time would also be reduced with 240 vs 120.....

Click to expand...

thanks for the load of info, +rep for this one

howsit i live in a country where we only use 220-240vac my question consists of many parts. As i have never grown indoors i don know wat to expect. first i will give u details. My grow room is 1.2m long by 2m high by .6 m deep in feet i think that converts to 4 by 6.5 by 1.9 almost 2. The area i will be using of that is the full length by half the depth so about 4 by 1 so here is my question can a 250w light be spread effectively over the grow area? And how hot will it get in that space? I can fit 2 fans both 4 inch one for intake and one 4 exhaust to try rectify the problem but the advantage is that from my grow cabinet to the outside is less than 1 inch (to the outside of the building from the fan inside the cabinet) so there is no distance to cover and the air can flow freely. The 250w hps is in the square type box reflector. Can i cover the front with perspex and drill holes in and cut a hole in the back and attach it to the exhaust ducting so that the hot air is essentially sucked out.. I have never used hid lights so i don know the temperatures they are capable of or their effective area i have not ordered the 250w yet so i could go 4 bigger but i can not increase the size of the 2 vents so im slightly limited it that way. Please help

ganja zulu said:

howsit i live in a country where we only use 220-240vac my question consists of many parts. As i have never grown indoors i don know wat to expect. first i will give u details. My grow room is 1.2m long by 2m high by .6 m deep in feet i think that converts to 4 by 6.5 by 1.9 almost 2. The area i will be using of that is the full length by half the depth so about 4 by 1 so here is my question can a 250w light be spread effectively over the grow area? And how hot will it get in that space? I can fit 2 fans both 4 inch one for intake and one 4 exhaust to try rectify the problem but the advantage is that from my grow cabinet to the outside is less than 1 inch (to the outside of the building from the fan inside the cabinet) so there is no distance to cover and the air can flow freely. The 250w hps is in the square type box reflector. Can i cover the front with perspex and drill holes in and cut a hole in the back and attach it to the exhaust ducting so that the hot air is essentially sucked out.. I have never used hid lights so i don know the temperatures they are capable of or their effective area i have not ordered the 250w yet so i could go 4 bigger but i can not increase the size of the 2 vents so im slightly limited it that way. Please help

Click to expand...

so here is my question can a 250w light be spread effectively over the grow area?
yes. the key will be maintaining the proper height of the lamp in relation to the plants... you will be raising the light as they grow...
the height is pretty simple to set- get the light as close to the plants as you can while you can still hold your hand under the light with no discomfort. then raise it up 2-3 inches.
i say raise it because you have to allow for the plant to grow, some days the plant will grow more than 3 inches if your taking care of it properly

And how hot will it get in that space?
thats hard to answer, your local conditions greatly affect this... humidity, wall coverings, ventilation, ambient temps, temp swings, altitude to name a few

I can fit 2 fans both 4 inch one for intake and one 4 exhaust to try rectify the problem...

the solution would be to put the inake fan (fresh air in) at the bottom, and the exhuast (hot air out) at the top, and take advantage of the natural convection currents in the air (heat rises, suck heat out from the top, push cold air in from the bottom)

I have never used hid lights...

one thing to keep in mind about HID is the ballasts also generate a good amount of heat, if you have a remote ballast(seperate from the lamp/reflector) it would be best to place it outside the grow cab... a 250w doesnt get that hot though, relatively speaking. it does get hot as hell, but no where near a 400, 600 or 1000w lamp.
a good idea before you get your plants in there would be to do a 'dry run', and let your setup run for a day or two by itself all shut up like you were in flowering, and see what the temps do...
also blowing air (can just be an additional fan inside the grow room) on the reflector is a great way to dissapate the heat if it still gets too hot with your intake/exhaust fans running.
another thing to remember is that weed is a tropical plant, and can withstand higher temps relatively well, however the higher your average temps are the mpore water they will drink, so you really have to keep an eye on the wiliting when using HID... they can wilt pretty quicky under HID lights if you forget a watering for a few days, so keep an eye on your medium

Sup all ,just burnin' one and peeping forums. Iam5toned, just wanted to give you props on taking the time out to help everyone and kick down some real world knowledge. I started to laugh when you said that you'd answer anyonez question concerning lighting, electricity etc.. But Man you really did, I read through 10 or 15 pages and your answers were indepth and obviously took some thought and time to compose.

Hellz yeah man!

jolly8541 said:

Sup all ,just burnin' one and peeping forums. Iam5toned, just wanted to give you props on taking the time out to help everyone and kick down some real world knowledge. I started to laugh when you said that you'd answer anyonez question concerning lighting, electricity etc.. But Man you really did, I read through 10 or 15 pages and your answers were indepth and obviously took some thought and time to compose.

Hellz yeah man!

Click to expand...

for sure probly the best thread ive found so far on electricity by far

thanx 4 the help. Just to provide the info that i left out. I live near the ocean, the hottest it gets in summer is 70 with the lowest in winter at about 64. we rarely get a heat wave and the hottest recorded temp was 86 for 1 day, then it dropped back down to about 70. the humidity hangs around 60% going up to about 65% down no lower than 59%. we lucky to have an incredibly stable climate. The fans i will be useing will be 90cubic meter/h 2 of them. I can run a vent from the hood of the light to the exhaust. I hope that helps to answer the q about what the temps might get to. All i need to know is am i gonna be able to use the 250w or is it an expensive gamble. I have a budget and the light alone takes an ugly chunk but iv already got most of my grow stuff like i say its just the lights now..

I am looking to wire up four computer fans to my new grow box and have run into a problem of wiring. So far I have shorted out one of the fans when I was testing out the wiring so thought I would consult someone who knows more about the subject. I used 16g outdoor wire to connect the fan to a plug plugged it into a dimmer and even though the dimmer was on low still shorted out the fan. The fans I have are 120mm silent cool master's, web site info is http://www.coolermaster-usa.com/product.php?product_id=2887 .what would you suggest for the wiring?

ganja zulu said:

thanx 4 the help. Just to provide the info that i left out. I live near the ocean, the hottest it gets in summer is 70 with the lowest in winter at about 64. we rarely get a heat wave and the hottest recorded temp was 86 for 1 day, then it dropped back down to about 70. the humidity hangs around 60% going up to about 65% down no lower than 59%. we lucky to have an incredibly stable climate. The fans i will be useing will be 90cubic meter/h 2 of them. I can run a vent from the hood of the light to the exhaust. I hope that helps to answer the q about what the temps might get to. All i need to know is am i gonna be able to use the 250w or is it an expensive gamble. I have a budget and the light alone takes an ugly chunk but iv already got most of my grow stuff like i say its just the lights now..

Click to expand...

it'll work out great for you!

Casemaker said:

I am looking to wire up four computer fans to my new grow box and have run into a problem of wiring. So far I have shorted out one of the fans when I was testing out the wiring so thought I would consult someone who knows more about the subject. I used 16g outdoor wire to connect the fan to a plug plugged it into a dimmer and even though the dimmer was on low still shorted out the fan. The fans I have are 120mm silent cool master's, web site info is http://www.coolermaster-usa.com/product.php?product_id=2887 .what would you suggest for the wiring?

Click to expand...

i would suggest not using a dimmer switch to control a motor, its not what there for.
i would also suggest to make sure your polarity is correct with the motor leads...
theres a couple of other things... like, what voltage are the fans? most pc fans ive run across take 12 or 24vdc. if you have them 'plugged into a dimmer' without sometype of a transformer, they will burn up as soon as you connect them
ps- you need a motor spped controller.... for whatever voltage your fans are running on

how can I wire multiple computer fans to a dc adapter?

ireaddd said:

how can I wire multiple computer fans to a dc adapter?

Click to expand...

you wire them in parallel.
all the postives splice together under one wire nut, and all the negatives splice together under another wirenut

If i have a four-light-socket bank of cfls and I only have 3 bulbs screwed in and one left out will the light bank use less energy than if four are in?

chronchron said:

If i have a four-light-socket bank of cfls and I only have 3 bulbs screwed in and one left out will the light bank use less energy than if four are in?

Click to expand...

seriously....

Im just making sure, cause you know those phone chargers use electricity even when they arent charging a phone.

Hey IAMSTONED, I hope you've been well. I have learned a lot from you, and I have successfully re-wired a lot of stuff. I've been very careful, and success!! Thank you good sire!!

I have a sealed room, and a dual hose portable ac unit with two hoses that exchange the air in my attic. The Exhaust hose from the ac unit in the grow room is really needing some boost. So, I bought this FPS 10 Negative/Positive Pressure Switch from FanTek which is supposed to switch ON a 115V device of your choice when positive or negative pressure is "sensed" in the ducting; As my device of choice, I chose a 6" HO Can Fan rated at 440CFM.

I have an extension cord in my attic for the power source.

How would I wire/connect the can fan to the pressure switch?

hwy420 said:

Hey IAMSTONED, I hope you've been well. I have learned a lot from you, and I have successfully re-wired a lot of stuff. I've been very careful, and success!! Thank you good sire!!

I have a sealed room, and a dual hose portable ac unit with two hoses that exchange the air in my attic. The Exhaust hose from the ac unit in the grow room is really needing some boost. So, I bought this FPS 10 Negative/Positive Pressure Switch from FanTek which is supposed to switch ON a 115V device of your choice when positive or negative pressure is "sensed" in the ducting; As my device of choice, I chose a 6" HO Can Fan rated at 440CFM.

I have an extension cord in my attic for the power source.

How would I wire/connect the can fan to the pressure switch?

Click to expand...

hopefully the a/c will have enough backpressure to activate the switch.
remember that swicth goes outside the duct... the two fittings need sampling tubes, one to atmosphere, one connected to the duct

Aww man, thank you so kindly - you are the bomb digity.

Cool, I was just making sure I could still use the extension cord, instead of romex & a junction box. That's awesome. Thanks for your time bro; This thread should be voted thread of the year.

thanks man, simple enough

Got a quick question:
Is it common for a rooms sockets, switches to just quit working?
Here is the situation:
one night, disposal went crazy...figured its been here since '98 it might have burnt the motor.
Next morning, my lights to the office no longer work. Huh? went the panel, no popped breaker...weird.
Figured better check the GFI's, sure as shit, they are fine....
I also know that when this circuit had been overloaded IN THE PAST it had tripped. There was nothing new added to the circuit to instantly pop overnight..
Thought okay, maybe the breaker went bad...Replaced the breaker with type QT 15 amp 2 switch breaker and wired it back up..With my fingers crossed and a quick prayer...
STILL NO FRICKIN LIGHTS. Now I am not an idiot, but have very little experience with electricity... I would have assumed by some random act that there was a neutral that came loose, cannot find one...What the heck is going on?