Electrical Question

maylee

Member
Remember a 100 amp panel is overloaded at 100 amps, this is the point of failure. Also the grow is running high current 12 hours straight. Any weak connection, that will equal heat buildup, will be a possible fire hazard down the road. This is the risk, any stupid reason the Fire Dept is called can mean years in the pokey if you are not in a state where it is legal.

Duty cycle, this just my opinion, 50 to 60 percent duty cycle max for grows, for a 100 amp service, that means a maximum of a 50 to 60 amp pull at maximum load.

Two 1K grow lamps - 2200 watt - an additional 10% loss in the ballast
A basic AC - 1400 watt
Another 1000 watt for fans, pumps, ect this is a rough guess.

2200+1400+1000=4600

4600 watts / 120 volts = 38.3 amps
6800 watts / 120 volts = 56.6 amps that's the 4 1kw HPS grow

I am thinking circuit breakers are maybe +- 10% so if you had a 40 amp circuit that means it could pop anywhere between 36 and 44 amps draw.

Electronic ballast, they are basically a switching power supply. what happens if you get low voltage?
Some quick math.

90 volts vs 120 volts and four 1K HPS lamps with solid state ballast.

At 90 volt we will still use 4400 watts, it's a switching power supply it will make up for the low volts :) , magnetic ballast will not do this.

4400 watts / 90 volts = 48.9 Amps
We will try this at 120 volts
4400 watts / 120 volts = 36.7 Amps
A 25% increase in current because of low voltage using solid state ballast.

Solid state ballast are more efficient than magnetic ballast however they can accelerate an overload situation if you get low voltage, undersized wire will cause low voltage.

Another factor is something called power factor. It's simply means how much the current and voltage are in phase. Extra hot days and you are hearing about brown outs - inductive loads can do odd things - can cause your current that is amps to go up yet the voltage is unchanged. Fans, AC's, motors, air pumps may have difficulty working. you could have 140 volts yet a fan will barley run like low voltage and overheat. This is rare but point is if you have a grow that is at the maximum as far as power goes, this kind of thing could cause a problem. Power factor can be a bit complicated this can tell more http://www.allaboutcircuits.com/vol_2/chpt_11/3.html

If I was your electrician for a 200 foot run a minimum of a 2 inch conduit.
Your going to dig the hole again so 3 inch for power and 2 inch for data, teco etc. If your a nice guy put a pull rope in the conduit to make it easy. You can do this as you are assembling the pipe or use a vacuum cleaner to suck a puffy thing on a small string to pull your larger rope in. And when you pull the wire pull in another pull rope so if you want to make any additions down the road it is easy.
 

fishwhistle

Active Member
Remember a 100 amp panel is overloaded at 100 amps, this is the point of failure. Also the grow is running high current 12 hours straight. Any weak connection, that will equal heat buildup, will be a possible fire hazard down the road. This is the risk, any stupid reason the Fire Dept is called can mean years in the pokey if you are not in a state where it is legal.

Duty cycle, this just my opinion, 50 to 60 percent duty cycle max for grows, for a 100 amp service, that means a maximum of a 50 to 60 amp pull at maximum load.

Two 1K grow lamps - 2200 watt - an additional 10% loss in the ballast
A basic AC - 1400 watt
Another 1000 watt for fans, pumps, ect this is a rough guess.

2200+1400+1000=4600

4600 watts / 120 volts = 38.3 amps
6800 watts / 120 volts = 56.6 amps that's the 4 1kw HPS grow

I am thinking circuit breakers are maybe +- 10% so if you had a 40 amp circuit that means it could pop anywhere between 36 and 44 amps draw.

Electronic ballast, they are basically a switching power supply. what happens if you get low voltage?
Some quick math.

90 volts vs 120 volts and four 1K HPS lamps with solid state ballast.

At 90 volt we will still use 4400 watts, it's a switching power supply it will make up for the low volts :) , magnetic ballast will not do this.

4400 watts / 90 volts = 48.9 Amps
We will try this at 120 volts
4400 watts / 120 volts = 36.7 Amps
A 25% increase in current because of low voltage using solid state ballast.

Solid state ballast are more efficient than magnetic ballast however they can accelerate an overload situation if you get low voltage, undersized wire will cause low voltage.

Another factor is something called power factor. It's simply means how much the current and voltage are in phase. Extra hot days and you are hearing about brown outs - inductive loads can do odd things - can cause your current that is amps to go up yet the voltage is unchanged. Fans, AC's, motors, air pumps may have difficulty working. you could have 140 volts yet a fan will barley run like low voltage and overheat. This is rare but point is if you have a grow that is at the maximum as far as power goes, this kind of thing could cause a problem. Power factor can be a bit complicated this can tell more http://www.allaboutcircuits.com/vol_2/chpt_11/3.html

If I was your electrician for a 200 foot run a minimum of a 2 inch conduit.
Your going to dig the hole again so 3 inch for power and 2 inch for data, teco etc. If your a nice guy put a pull rope in the conduit to make it easy. You can do this as you are assembling the pipe or use a vacuum cleaner to suck a puffy thing on a small string to pull your larger rope in. And when you pull the wire pull in another pull rope so if you want to make any additions down the road it is easy.
Excellent,this is the kind of input i need.Im definitely going at least 2'' on the conduit(w/pull rope!)and im stepping up wire size from 1 to 1/0 so i have a safety factor.I will check with electrician on the panel size thing,i have kind of calculated 70-80 amps max usage,I hope more like 50-60.All the large power users,ballasts(quantums) and A/C will be 240v.Electrical is my downfall but im learning and while i will do as much as i can a pro will be doing the critical stuff,safety and not maxing things out are critical to me.I am striving for energy efficiency for a few reasons,one because im a cheap bastard and two because its the right thing to do.I just picked up a solar attic ventilator to help keep temps down and all Framing is 2x6 with R30 insulation in the walls and R60 blown in the attic,anything to control temps as it dips into the high twenty's in the winter and well over a hundred in the summer here.
Many thanks to everyone for their input it is much appreciated!Foundation is done and framing will begin soon after that comes electrical and then the inside buildout.By the way this will be a 100% legal medical grow!
 

maxed

Member
3k is about right. I just had my buddy do this same thing for me. the materials alone were $55 for 25' of 10/2. I believe the 12/2 was about $80 for 100'. but add in all the breakers, $30 for each 30AMP switch, connectors, boxes yadda yadda... it came out to close to $1200 just for materials. We have a 100amp 3 phase delta. We built the frame from the floor up. Built in 4 rooms. Drywall, Insulation, the whole 9. The electrician ran all the wiring to code through the studs and placed outlets throughout the rooms. We have 2 -20 Amp breakers in each room along with 2 - 30-amp 4 prong outside of and between rooms so we can flip flop rooms and run half the ballasts. Each 30amp will hold 6 1000W 240v, which then can be connected to a flipbox and run to the second room. you dont need to run new subpanels for each room though. Subpanels are costly and if you can just run from your main panel and have enough spaces for breakers i'd go that way. Just make sure everything is to code, that's one of the top priorities.
 

zvuv

Active Member
I ran #10 wires from the power lines in my crawl space up to a breaker box in my closet. I have one 600W hps. The breakers are rated 15A although 12' of #10 can carry much heavier currents. I also wired 100A 220v into my shop to run a welder n'stuff.

Electrical wiring is not hard if you understand the basics but it has to be done to high standards or you are taking a risk.

Risks include : Shock hazard & fire hazard.

Fire usually comes from a hot spot somewhere in the wiring, either from an undersized cable or a poor connection. The voltage drop from too much resistance is a secondary concern. Aluminum is a great conductor but making low resistance connections is a trick. Al forms a very hard high resistance oxide coating coating (grinding wheels are made from Al oxides). In the 60's a lot of houses were wired with aluminum which was then just clamped into the outlet and switch terminals. Such houses are very prone to electrical fires. Nowadays they make special pigtail connectors to connect aluminum wiring.

I recommend:

a. Go by a real electrical supply store, explain your project and discuss the right way to do it. Most of those guys know the code and will be happy to give you advice. Don't cheap out on materials. Overbuild where you can.

b. If you are wiring 220v in the US make sure you understand how this involves two 120v hot wires and their relation to ground and neutral etc.

c. If you own the house, check with your insurance co and verify that they will cover an electrical fire even if you did the wiring and it somehow failed to meet code.


d. Work very carefuly and only when your head is clear (know I'm sayin' ? :) ). Shut off power even if you think it's not necessary and even then double check with a meter that the circuit isnt hot. I have twice discovered after the fact that I had been working on a hot circuit.

e. When it's all setup and running, periodicaly check wires, outlets and other connection to see if they are warm.

Those plugin outlets testers that light up and tell you whether the outlet is wired correctly are very handy, though I don't know if they are available for 220v

80A @220v = 17.6 kw. Will the extra consumption be noticed by your utility co?
 

maylee

Member
This is what you have to work with as far as power budget goes.
A typical household service panel is 100 amps at 240 volts.

240 Volts * 100 Amps = 24000 Watts
or
120 Volts * 100 Amps = 12000 Watts
120 Volts * 100 Amps = 12000 Watts
Split_phase2.png

You have a center tap transformer connected to a grounded neutral this is what feeds your house.

So your point of overload is 24000 Watts +- 10%

This may be a bit unclear,
"Duty cycle, this just my opinion, 50 to 60 percent duty cycle max for grows, for a 100 amp service, that means a maximum of a 50 to 60 amp pull at maximum load."
That's 6000 to 7200 watts per leg for a total of 12000 to 14400 watts at a 50 to 60 percent load.

3wire_resistive_loads.PNG
You would want to balance your load so two 1000 watt HPS on one side and two 1000 watt HPS on the other.

Remember sold state ballast, for a 1000 watt HPS plus 100 more watts for the ballast.

This is the specks from Nextgen http://www.randmsupply.com/images/link/Brochure.pdf
90 to 260 volt range
..9.5 amps at 120 volts that's 1140 watts - 1000 watts for the lamp 140 watts for the ballast
12.7 amps at ..90 volts that's 1140 watts - 1000 watts for the lamp 140 watts for the ballast

A 14 Gauge wire is good for 15 amps max
A 12 Gauge wire is good for 20 amps max

I would not feel bad about using 12 gauge wires for each 15 amp circuit

So a 6800 watts for a four 1000 Watt HPS grow with accessories is ok, it's about a 1/4 of your service, just remember you are also running your home stuff too, lights, washer/dryer, AC's etc.
 

maylee

Member
For a 1000 watt HPS digital lamp ballast which uses 1140 watts. Showing different wire runs lengths and using different wire sizes. Showing how much power is lost in your feed line and current used buy the ballast and its voltage with different sized feed wire. For a 50 foot extension use 100 feet of wire as it takes 50 feet to get there and 50 feet to return.
For 200 feet of wire in a conduit use 400 feet - again you get there and return so it is a total of 400 feet of wire.

12 foot.png
25 foot.png
50 foot.png100 feet.png200 foot.png400 feet.png800 feet.png
 
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