Growroom Electricity and Wiring

[iTarzan]

I have another question for the electrical gurus. Rives I like to think this thread is a source of entertainment for you. Hopefully the endless question amuse you and pass some time.

I have a 6" 400 cfm centrifugal duct fan drawing in outside air from a 6" vent tubing. The fan has a 3 prong plug. I need to install a fan speed control. I was just going to buy one but then I remembered I had this unused but a few yeas old Vari-Speed control.

I scavenged a plug cord from it but don't remember how it goes together. It has 2 red wires and one green one. Which red is power and which is neutral. I assume the green is ground.

I want to be able to plug the timer into the outlet and the fan into this speed control.

What do I need to get and do? I guess I need a male 3 prong plug connected to some 3 wire and a 3 prong female outlet and 3 wire.

Here are the pics of what I have.

 

[rives]

I have another question for the electrical gurus. Rives I like to think this thread is a source of entertainment for you. Hopefully the endless question amuse you and pass some time.

I have a 6" 400 cfm centrifugal duct fan drawing in outside air from a 6" vent tubing. The fan has a 3 prong plug. I need to install a fan speed control. I was just going to buy one but then I remembered I had this unused but a few yeas old Vari-Speed control.

I scavenged a plug cord from it but don't remember how it goes together. It has 2 red wires and one green one. Which red is power and which is neutral. I assume the green is ground.

I want to be able to plug the timer into the outlet and the fan into this speed control.

What do I need to get and do? I guess I need a male 3 prong plug connected to some 3 wire and a 3 prong female outlet and 3 wire.

From the directions that I found, you can apparently interchange the red wires BUT neither of them goes to the neutral. One goes to the incoming hot wire, and the other will become the hot wire going to your fan motor. Yes, you can get a handy-box to mount the control in, a couple of strain reliefs, male and female cord caps, and some 16/3 cord. You will hook up one of your red leads to the black wire coming from the male cap, the other red lead to the black wire going to the female (the black wires will connect to the copper screw in each cap, the white wires to the silver ones), and join the white wires together. The grounds should connect together also, but with a 3rd one grounding the handy box also tied in with them.

https://www.kbelectronics.com/manuals/kbwc_manual.pdf

 

[iTarzan]

Thanks rives. I am heading to the garage right now.

 

[iTarzan]

I have it all connected and functioning properly. Thanks for the help you have given me numerous times rives. You are a very valuable member on IC.

Phillthy started a great thread and you have been instrumental in keeping the flow of information going.

My grow room has evolved and is safer and will be more productive. It is way better to have too much cooling power and need a fan speed control then not enough cooling like I usually have to struggle with.

 

[2chains]

First time grower in Southern Alberta.

Looking at a small scale 4x4 room grow tent in my unfinished basement with 1000A LED/oscillating fan 30A/6" inline fan 110A with carbon filter (but not sure if I will be needing ac/heater/humidifier down the road anyone feel free to chime in if you have grown in this neck of the woods ).

My understanding is code allows 1440W max on 15A service for a complete single circuit running from a single pole 15A breaker. As I will only have room for one receptacle in this circuit as it will be near maxed with the one plug....am I better off to run split circuit from 2pole 15A breaker so I have use of 120 at each plug in at this receptacle? I am thinking of running two of these split circuits at two receptacle locations.

Is this a safe and/or common practise in this circumstance? Are there better options to achieve this?

 

[Jhhnn]

First time grower in Southern Alberta.

Looking at a small scale 4x4 room grow tent in my unfinished basement with 1000A LED/oscillating fan 30A/6" inline fan 110A with carbon filter (but not sure if I will be needing ac/heater/humidifier down the road anyone feel free to chime in if you have grown in this neck of the woods ).

My understanding is code allows 1440W max on 15A service for a complete single circuit running from a single pole 15A breaker. As I will only have room for one receptacle in this circuit as it will be near maxed with the one plug....am I better off to run split circuit from 2pole 15A breaker so I have use of 120 at each plug in at this receptacle? I am thinking of running two of these split circuits at two receptacle locations.

Is this a safe and/or common practise in this circumstance? Are there better options to achieve this?

I suggest using #12 wire & a 20A breaker for 1920w continuous. It costs little more & would have excellent safety margin for what you're talking about. If you use 12/3 w ground cable you could readily upgrade to a split phase circuit & ganged breakers down the road if the breaker panel has the avail space.

I'd advise a 4plex receptacle for single phase & two of them for split phase.

Dunno what the humidity is like in Alberta but it's probably not a concern in a large-ish lung room space. The need for a heater depends on what kind of temps the space normally experiences.

 

[2chains]

@Jhhnn
Thanks for the quick reply. 20A circuit is a great option I hadn't thought of. I have newish house so lots of room at the box for expansion down the road.

 

[everydayJoe]

I have a similar setup as you. When I do electrical, I tend to be a bit conservative with the anticipated loads to always be on safe side. If I were running a 1000w light, I'd have that on a separate 20amp circuit run with 12/2 wire. If your light is compatible it's not a bad idea idea to run that breaker as 220v since the light will run smoother/cooler on 220v compared to 120v. I'd then have all the other stuff (fans, dehumidifier, etc) on a second 120v/20 amp breaker run with 12/2. Also consider possible need for heater or air conditioner, which depending on the size may require its own circuit. In this case, consider a third 20amp/220v breaker with a hard wired thermostat to run them.

Depending on how your house is designed and how far your main panel is from where you are growing, it might be easiest to set up a sub panel in your unfinished basement from which you can then run all these circuits. Maybe a 50amp subpanel run with 6/3 on a 50amp breaker, or a 40amp subpanel run with 8/3 protected by a 40amp breaker at the main panel. At this point though things get complicated enough that you'll really want to know what your doing or hire an electrician.

 

[2chains]

@everydayJoe

Thanks for the input. As a noob I had a confusing time with the LED ratings and ended up buying Mars II LED 1600 which is 730watts rating not 1600w. I'm not sure if this will change your recommendations...

By 220v breaker are you talking double pole with two wires operating as hot?

Thankful for an unfinished basement as I can adjust if needed.

I've already run a circuit w/20A single pole breaker with the 12/2 wire to an 4plex--I think code calls for one GFCI so added one. I can easily swap out to 20A double pole breaker and swap to single outlet if that's what brings more head room on the circuits.

I also ran a second identical circuit but w/15A 14/2 single pole breaker and was planning to use for everything other than lights i.e. scrubber fan/oscillating fan/timer/humidifier I can easily add 15A double pole breaker here as well but hoping not to have to change the wiring to 12/2 maybe just add another 20A single pole circuit is what I'm thinking.

Do these changes sound reasonable? I don't have anything running yet so swapping out is not an issue. I won't set anything up until I know all is safe.

One noob question::I do have separate basement heating zone(damper system) and have free standing A/C unit on the exterior of my house. Will that be sufficient or would I need additional A/C or heater?

thanks for the assistance!

 

[2chains]

Got my 15A GFCI w/14-2 installed w/single pole breaker plenty to power my miscellaneous gear thanks to this thread!

Next step ...
For the lights--My LED's for veg room 4x4 Solarstorm 440 runs @ 1.46A/240v -2.92A/120v for flower room 5x5 the Mars Hydro II runs @ 6.54A/110v--3.46A/220v.

Is it safe running extension cords to lighting outlets and is there a maximum length? Will 12g wire be adequate?

 

[Jhhnn]

Got my 15A GFCI w/14-2 installed w/single pole breaker plenty to power my miscellaneous gear thanks to this thread!

Next step ...
For the lights--My LED's for veg room 4x4 Solarstorm 440 runs @ 1.46A/240v -2.92A/120v for flower room 5x5 the Mars Hydro II runs @ 6.54A/110v--3.46A/220v.

Is it safe running extension cords to lighting outlets and is there a maximum length? Will 12g wire be adequate?

If you have to use extension cords then #14 would be adequate at your current draw. The 80% rule still applies.

https://www.stayonline.com/reference-circuit-ampacity.aspx

 

[FredyJohnSmith]

That's one nice discussion you guys are sharing here, proper wiring should be done for the grow room to avoid any sort of accidents.

 

[Jhhnn]

That's one nice discussion you guys are sharing here, proper wiring should be done for the grow room to avoid any sort of accidents.

Nice of you to say so. Rives is the guy- I just try to pitch in a little.

Safety matters, a lot. People get away with ignoring it or not understanding it until it jumps up & bites 'em in the ass, hard.

I mean, what's the worst case scenario? Burning down the house. If I can help people avoid that, I will.

 

[Easy7]

If 4 15 amp outlets are on a 20 amp breaker and the wires go to the terminals on the outlet and no wires by pass, am I limited by the breaker 80% rule or the outlet 80% rule?

Cause a 15 amp outlet can handle 12 and the breaker 16 and it has to go through an outelts terminals to get to other outlets.

Thanks

 

[RoyalFlush]

If 4 15 amp outlets are on a 20 amp breaker and the wires go to the terminals on the outlet and no wires by pass, am I limited by the breaker 80% rule or the outlet 80% rule?

Cause a 15 amp outlet can handle 12 and the breaker 16 and it has to go through an outelts terminals to get to other outlets.

Thanks

Both. Do not over load an individual outlet and Do not over load the complete circuit.

Good Examples:
12+4+0+0=16a
0+0+4+12=16a
4+4+4+4=16a
5+5+3+3=16a
2+11+3+0=16a

Bad Example:
12+12+12+12=48 amps ( 100% guaranteed FIRE )
Do not use all outlets at max limit at once.

 

[rives]

If 4 15 amp outlets are on a 20 amp breaker and the wires go to the terminals on the outlet and no wires by pass, am I limited by the breaker 80% rule or the outlet 80% rule?

Cause a 15 amp outlet can handle 12 and the breaker 16 and it has to go through an outelts terminals to get to other outlets.

Thanks

RoyalFlush is correct in that you don't want to overload either individual outlets or the complete circuit, but my impression is that you are asking about the amperage that can flow through the daisy-chain connections on the back of the receptacle.

This is actually a really interesting question that delves into a bunch of things that could and should be better addressed by the Code.

1 - the UL listing for the receptacle ampacity applies only to the face of the receptacle, not the back connections.

2 - 15a receptacles are allowed on a 20a circuit, but only if there is more than one receptacle on the circuit.

3 - It is widely held that the there are no manufacturing differences between the 15a and 20a receptacles other than the ground configuration, and they are capable of supplying the same level of power.

4 - While not a code requirement, "best practice" calls for using the pigtail method to wire the receptacles rather than daisy-chaining through them. This means that the supply wires are spliced and wire-nutted, with short jumpers included in the splice to power the receptacle. The additional connections on the back of the receptacle are then only used when you want to split the receptacle. This keeps the current to downstream receptacles flowing through the conductors rather than through each upstream receptacle, and gives the benefit of keeping the remainder of the circuit powered if a receptacle is removed. The overwhelming majority of receptacle failures that I've seen over the years are related to the back wiring (see point 5).

5 - My personal prejudice is to NEVER use the style of receptacle that you can "stab" the back-wiring into, and only use the commercial grade (or better) style that uses screw-plate connections. The stab style depends on spring tension to maintain the connection. The quality of that connection is questionable under the best of conditions, and gets worse when heated by heavy current flowing. The stab-style is marginally faster to install, but they are very prone to early failure and should never be used where you anticipate using the receptacles continuously with relatively heavy loads.

Whew...

 

[Easy7]

So why have 15 amp outlets on a 20 amp breaker?

I was hoping that the outlets could pass thru that much but not through the receptacle. So I'm really limited to 12 amps on a 20 amp circuit?

https://www.bobvila.com/posts/82844-15-amp-outlets-in-a-20-amp-circuit?page=1

^^^According to those responses perhaps I'm good running 16 and staying below the 80% (16 amp) of the 20 amp breaker.

 

[Easy7]

RoyalFlush is correct in that you don't want to overload either individual outlets or the complete circuit, but my impression is that you are asking about the amperage that can flow through the daisy-chain connections on the back of the receptacle.

This is actually a really interesting question that delves into a bunch of things that could and should be better addressed by the Code.

1 - the UL listing for the receptacle ampacity applies only to the face of the receptacle, not the back connections.

2 - 15a receptacles are allowed on a 20a circuit, but only if here is more than one receptacle on the circuit.

3 - It is widely held that the there are no manufacturing differences between the 15a and 20a receptacles other than the ground configuration, and they are capable of supplying the same level of power.

4 - While not a code requirement, "best practice" calls for using the pigtail method to wire the receptacles rather than daisy-chaining through them. This means that the supply wires are spliced and wire-nutted, with short jumpers included in the splice to power the receptacle. The additional connections on the back of the receptacle are then only used when you want to split the receptacle.

5 - My personal prejudice is to NEVER use the style of receptacle that you can "stab" the back-wiring into, and only use the commercial grade (or better) style that uses screw connections. The stab style depends on spring tension to maintain the connection. The quality of that connection is questionable under the best of conditions, and gets worse when heated by heavy current flowing. The stab-style is marginally faster to install, but they are very prone to early failure and should never be used where you anticipate using the receptacles continuously with relatively heavy loads.

Correct, that's what' I'm asking. Currently renting a house from family and fixing it up. It's an old house and had a garage that's now a room. Rebuilding it hoping someday there is somewhat of a grow. Keeping that in mind. Could always rebuild it in the future. Was hoping to just have a little.

The owner is an electrician but a bit of a cheapo.

 

[Jhhnn]

If 4 15 amp outlets are on a 20 amp breaker and the wires go to the terminals on the outlet and no wires by pass, am I limited by the breaker 80% rule or the outlet 80% rule?

Cause a 15 amp outlet can handle 12 and the breaker 16 and it has to go through an outelts terminals to get to other outlets.

Thanks

The breaker should be sized to the wire & the 80% rule applies to that combination.

For example, a 20A breaker may be used with #12 wire & the combined continuous load for all the receptacles on that circuit should not exceed 16A. A 15A breaker may be used with #14 wire & a continuous load of 12A. Never use a breaker bigger than that recommended for the wire size in question.

 

[Jhhnn]

If you're running new wire the smart answer is to run 10/3 w/ ground from a ganged 30A 240v breaker in the main panel to a new subpanel in the garage. You can then break that down into smaller 120v or 240v circuits to run the equipment. It's a common way to wire a garage that's also used as a shop.