Electrical help - multiple power strips

So here's the deal. I don't like to just ask questions and get a "yes" or "no." I like to fully understand whatever it is I am seeking. Right now I am in the process of building my second grow box. This one is going to be a dual chamber box (similar to MicroGrower's) with a dedicated veg side and flower side. I am going for complete stealth as well. Ideally, I want to have one power strip or surge protector on the back outside of the box. In doing so, I will have another power strip in each of the chambers. So my fans and lights in the veg chamber will be plugged into a power strip in the veg chamber, and the same in the flower chamber. This way, I will have one cord coming out from the veg chamber's power strip, and one cord coming out from the flower chamber's power strip. These two cords will then plug into the "main" power strip on the outside back of the box. I just like to keep things nice and neat. I'm pretty OCD. I tell you all of this to say this: I will essentially have two separate power strips plugged into another power strip. My question is: how do I determine if all is safe, i.e., it won't overload the circuit? I am running CFLs and case fans. I'm assuming I need to do something with adding up the amps of everything I have plugged in and go from there? Just curious as to how I double check my electronics and make sure I don't have a safety hazard. Thanks to anyone who can offer any advice. Cheers.

Been down this road myself bro. Took me a whole day of plug in here as wait to see of the breaker tripped then I'd move to the next plug. My nitemare was leaving for work the breaker tripping and them getting no light whatsoever. Thatd suck big time. I don't think it's a safety issue just that the breaker will trip. Sorry in not much help

from what I have read as long as the amount of electricity doesn't exceed the amount for the room you can have a bunch of things hooked up to one plug. Not the electrical answer you were looking for I'm sorry.

For what its worth I have 2 Power strips with 4 cfl on each plugged into a main power strip that is also running 2 PC fans. The main power strip is plugged into a surge protector that I also have my 50" plasma plugged into. All these things are all on one wall outlet, been like this for a while now.

If it goes over the limit,it should trip the strip...but you can add up how many ihms everything uses to see if you are under.The power strip should say how many ohms its rated for...same with bulbs...

computer fans and cfls won't be enough draw to pose a risk. To trip the typical household breaker would be 15 amps, stuff like running a air conditioner and watching tv and starting to vacume the living room is what trips breakers

Edited by Meatplow, 22 May 2012 - 03:20 AM.

OneDay-
To quote that greasy, faded old sign I saw on a garage wall many years ago, "Answers are $1.00; correct answers are $5.00; dumb looks are still free."
Now that I've satisfied my evil twin who made me type that, here's some better info.
The correct way to check this is with an amp meter, and measure the draw on each chamber's circuits as it is starting up - lights, fans, everything simultaneously. But most peeps don't have an amp meter lying around, so you can back into it fairly safely.
Just add the watts for every device in a chamber, and divide by 120 (volts), this will give you amps needed. Deduct 10 - 20% to this for safe overhead - if you are using heavy fans (like a vortex or CanFan with 400+CFM rating) they will draw more on startup than once running, therefore the extra overhead. Lower wattage CFL's (up to 42W actual) are self-ballasted and have very little surge on startup; HID ballasts have more than CFL's; not sure about the 125+ CFL's (don't use them) but wouldnt expect it to be significant.
If you are running bathroom "fart" fans, they are not as bad as heavy fans but still draw more current to start; recycled PC chassis fans even less.
Once you have this calculated for each chamber, check the rating on each chamber's power strip (should be marked on the reset breaker button) and be sure it's rated at about 20% more than your calculation (overhead mentioned above).
Not making any warranties here, but unless you go hog wild with multi-layer cascaded y-splitters it will be really hard to overload a 10amp breaker in each chamber.
Now for the OCD part - the third breaker on the exterior of your cabinet - bypass this in favor of a good quality three way three-prong grounded splitter from Homey Depot / Lowes, etc. The third breaker in this case is not necessary, and is just one more thing to fail and kill both chambers until you discover the malfunction. Get the solid molded plastic kind of splitter that hurts when you drop it on your toe. Plug each breaker strip into this and you're good to go (and still neat).

If you are using an extension cord between your chamber and the house circuit, keep it as short as possible and buy the heaviest gauge three wire grounded cord you can get (14gauge minimum recommended). Or preferred, plug the three way splitter into your house circuit and plug each power strip directly into the splitter.

You also have to be concerned with the amperage of the house circuit, and equally important what else is on the house circuit. For example, a 20 amp circuit can handle 2400 watts minus your 20% safety overhead, or an effective load of "about" 2000 watts. You can check the rating in your breaker panel for that circuit, but it's trial and error for how many lights' outlets, appliances, etc., are on the circuit. Turn everything in the house on, kill the breaker, and check to see what went off. Use a desk lamp to check un-used wall outlets. Add them up and deduct from your circuit's capacity.

Avoid electric heaters on the same circuit. Watch carefully when starting a vacuum cleaner on the same house circuit; and don't plug one into your power strip. And don't use your hair dryer while you're in your grow chamber (OK, I know, that last one was unnecessary, but WTF, it's free advice!!!)

Hope this is helpful & good luck.

Edited by Olde School, 22 May 2012 - 06:45 AM.

Just plug the main strip into a GFCI ( ground fault circuit interrupt ) and you will be fine. If a surge or higher amperage passes thru it it will trip like a breaker but just trip that outlet' not whole circuit. If you don't have a GFCI you can buy them for like ten bucks at home depot and put it in place of a regular outlet. That should solve your issue as long as your not putting some big hid light on there too. Then it'll prob keep trip in. Good luck

Fantastic info, Olde. That's exactly what I was looking for. Shouldn't be a problem.

Olde School know what he is talking about.

It is all about Amps.

All of the outlets in your room are likely wired to one breaker. That breaker will be capable of handling either 15 or 20 amps. The outlet plate on your wall has tow outlets (duplex). Each outlet, no matter what breaker they are on is rated for 15 amps.

Your power strips will have an amp rating, likely no more than 15 amp. So, given the way you want to build this, this will be your limiting factor. You will not be able to pull any more than 15 amps.

And, as Olde Shool said, you should be fine. Small fans don't draw a lot of current. I have a 4" duct fan that is rated at, ready - .25 amps. Running four of them would draw 1 amp.

CFL pull very low amps also. a 60W replacement CFL is only 13W, so at 120V that would pull just under .11 amps.

So you should have plenty of power and still be safe. So my calculations are:

15A - 20% safety margin = 12A

Four 4" .25W duct fans = 1A

100 13W CFLs = 11 A (just being silly)

Total draw = 11A

You should be MORE than fine

Olde School know what he is talking about.

It is all about Amps.

All of the outlets in your room are likely wired to one breaker. That breaker will be capable of handling either 15 or 20 amps. The outlet plate on your wall has tow outlets (duplex). Each outlet, no matter what breaker they are on is rated for 15 amps.

Your power strips will have an amp rating, likely no more than 15 amp. So, given the way you want to build this, this will be your limiting factor. You will not be able to pull any more than 15 amps.

And, as Olde Shool said, you should be fine. Small fans don't draw a lot of current. I have a 4" duct fan that is rated at, ready - .25 amps. Running four of them would draw 1 amp.

CFL pull very low amps also. a 60W replacement CFL is only 13W, so at 120V that would pull just under .11 amps.

So you should have plenty of power and still be safe. So my calculations are:

15A - 20% safety margin = 12A

Four 4" .25W duct fans = 1A

100 13W CFLs = 11 A (just being silly)

Total draw = 11A

You should be MORE than fine

Absolutely. I figured I should be fine, but wanted to double check. Safety first. Each chamber will have no more than 2 case fans and CFLs. The veg chamber will probably have six or so 23w CFLs and the flower chamber will have four 55w CFLs. So I shouldn't have a problem. Thinking about building a bubble bucket for clones next. But got to do my research...Thanks for the great info, blades.

Nothing wrong with being safe, especially with electricity.

Good luck on your grow.

Absolutely. I figured I should be fine, but wanted to double check. Safety first. Each chamber will have no more than 2 case fans and CFLs. The veg chamber will probably have six or so 23w CFLs and the flower chamber will have four 55w CFLs. So I shouldn't have a problem. Thinking about building a bubble bucket for clones next. But got to do my research...Thanks for the great info, blades.

OneDay, the bubble bucket is a sweet project & very simple to build. Swing by your friendly neighborhood grow store & pick up about (20) 2" net pots (you'll always need some spares). Then go to WallyWorld and pick up a Sterilite 12 quart plastic container. I like this model because the top is relatively flat, has a good amount of real estate for holes, and is the proper depth. Then, on your way home stop at HomeyDepot and pick up a 2" hole saw. It's a good idea to take one of the net pots with you to check the diameter of the hole saw before purchasing.
Now if you're true to the OCD thing (I am) you can lay out three rows of five holes each on graph paper, evenly spaced in an area that will fit along the long axis of the container lid. Keep your hole edges all inside the little recessed area across the top of the container lid, so the net pots fit properly. Sure, the even spacing makes it look more professional, but it also insures a more even distribution of bubbles once up and running. Tape the graph paper to the lid and punch a nail hole through the lid in the center of each circle. Use this as the guide hole for your hole saw when drilling through the lid. Keep a scrap piece of 2X4 under your drill area.
Be ready to cuss just when the hole saw cuts through the lid & hits the 2X4, because the lid will spin around and knock the shit out of your shin. But WTF, we're men, we like power tools, and scars build character. Besides, this only happens once before you figure out how to hold it down. Clean the burrs off each hole with a utility knife & you're ready for a dual outlet pump, a couple of 10" air stones, and aquarium tubing to get you up & running. Fill the container to within about 1/4" of the bottom of the net post & you're ready for clones.
Do NOT try to cut these holes with a utility knife. That plastic is as tough as, well... plastic. Utility knife blades will break, make uneven holes, and you will have to apply so much force that you are at risk of a slip causing a serious injury. You NEED most of your fingers to become an effective cloner.
Two of these side-by-side will hold (30) clones, and is the perfect size for one humidity dome placed crosswise across both containers. If you can keep the spider mites away, this setup will work like a champ. That's the only problem I've EVER had with clones - once the suckers get in your grow area, the first symptom is your clones stop rooting and start dying.
BTW, I much prefer and highly recommend rapid rooter plugs to hold your cuttings, they are the perfect medium for holding moisture, rooting effectively, and transplanting into any medium. Plus they change color to a lighter brown if they are not retaining enough water to keep the clones from wilting.
Now, go forth and prosper!!!

OneDay, the bubble bucket is a sweet project & very simple to build. Swing by your friendly neighborhood grow store & pick up about (20) 2" net pots (you'll always need some spares). Then go to WallyWorld and pick up a Sterilite 12 quart plastic container. I like this model because the top is relatively flat, has a good amount of real estate for holes, and is the proper depth. Then, on your way home stop at HomeyDepot and pick up a 2" hole saw. It's a good idea to take one of the net pots with you to check the diameter of the hole saw before purchasing.
Now if you're true to the OCD thing (I am) you can lay out three rows of five holes each on graph paper, evenly spaced in an area that will fit along the long axis of the container lid. Keep your hole edges all inside the little recessed area across the top of the container lid, so the net pots fit properly. Sure, the even spacing makes it look more professional, but it also insures a more even distribution of bubbles once up and running. Tape the graph paper to the lid and punch a nail hole through the lid in the center of each circle. Use this as the guide hole for your hole saw when drilling through the lid. Keep a scrap piece of 2X4 under your drill area.
Be ready to cuss just when the hole saw cuts through the lid & hits the 2X4, because the lid will spin around and knock the shit out of your shin. But WTF, we're men, we like power tools, and scars build character. Besides, this only happens once before you figure out how to hold it down. Clean the burrs off each hole with a utility knife & you're ready for a dual outlet pump, a couple of 10" air stones, and aquarium tubing to get you up & running. Fill the container to within about 1/4" of the bottom of the net post & you're ready for clones.
Do NOT try to cut these holes with a utility knife. That plastic is as tough as, well... plastic. Utility knife blades will break, make uneven holes, and you will have to apply so much force that you are at risk of a slip causing a serious injury. You NEED most of your fingers to become an effective cloner.
Two of these side-by-side will hold (30) clones, and is the perfect size for one humidity dome placed crosswise across both containers. If you can keep the spider mites away, this setup will work like a champ. That's the only problem I've EVER had with clones - once the suckers get in your grow area, the first symptom is your clones stop rooting and start dying.
BTW, I much prefer and highly recommend rapid rooter plugs to hold your cuttings, they are the perfect medium for holding moisture, rooting effectively, and transplanting into any medium. Plus they change color to a lighter brown if they are not retaining enough water to keep the clones from wilting.
Now, go forth and prosper!!!

Fantastic advice! Thanks, brother. Thankfully, I already have most of the tools I will need and a whole set of hole saw bits so I'm sure I've got one that fits. But I am thinking about doing the DIY design in a bucket with seven (7) clone sites. Mainly because the bucket is taller and I'll get them closer to the light. Plus, and most importantly, I won't ever be taking more than 7 clones at a time due to my limited space. I'm still probably a month or so away from building the cloner. Priority right now is finishing the new box, or at least the flower chamber so I can get what I've currently got vegging under some flowering lights. Thanks again.

Fantastic advice! Thanks, brother. Thankfully, I already have most of the tools I will need and a whole set of hole saw bits so I'm sure I've got one that fits. But I am thinking about doing the DIY design in a bucket with seven (7) clone sites. Mainly because the bucket is taller and I'll get them closer to the light. Plus, and most importantly, I won't ever be taking more than 7 clones at a time due to my limited space. I'm still probably a month or so away from building the cloner. Priority right now is finishing the new box, or at least the flower chamber so I can get what I've currently got vegging under some flowering lights. Thanks again.

Good point, you can modify the design / # of holes with no problem. But personally, I find the bigger buckets to be overkill for a bubbler. I never could get a bubble pattern I was satisfied with, that's why I ended up with the shorter rectangle design.
Now if you're going with an aero clone design using a fogger, or even PVC pipe & spinners with a pressure pump, that's a perfect fit for a 4-5 gal. bucket design.
Best of luck with your grow box.

OK, guys, now I have a question. Not to thread jack but I don't understand these micro-grows. Why do you grow so many plants in a small space? Wouldn't it be better to grow less plants to a bigger size?

OK, guys, now I have a question. Not to thread jack but I don't understand these micro-grows. Why do you grow so many plants in a small space? Wouldn't it be better to grow less plants to a bigger size?

Marsdude, it's all about yield & your preferred growing style. The premise behind more plants per square foot is what makes up sea of green (SOG) or Screen of green (SCROG). The basis is more top colas (the heaviest yielding part of the plant) per square foot. Each plant will yield less than any single plant grown to larger proportions, but the aggregate of all those top colas in a SOG/SCROG environment will outweigh single plants.
This is not limited to micro grows, it's just as effective under HID lights of all sizes; only difference being the footprint of your grow area. In fact, the stronger the light, the more effective this technique will be.
SCROG can easily be adapted to dirt grows, but SOG is generally a hydro-only technique due to the large number of plants crammed into a small area. A 5" pot in hydro will easily support a plant to it's full potential, whereas in dirt you need a 5 gal. or larger container.
Another advantage to more plants per square foot is to look for the best mother. You can grow out a batch of seed and select the best (strength, taste, yield, etc.) of the bunch to grow out as a mother, retaining the strain for as long as you like. The only problem with this is the number of mothers collected. You start out with one, then get another, and another, and another... it really hurts to cull one of those as your mother base expands. But, what a nice problem to have!!!!!