Yep. Safety first. Best put a 3 prong plug on the pump anyway & it'll plug right in to either solution.
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Growroom Electricity and Wiring
- Thread starter Phillthy
- Start date
Yep. Safety first. Best put a 3 prong plug on the pump anyway & it'll plug right in to either solution.
T
TwinTurboGuy
3 Phase Power
3 Phase Power
Hello guys,
I plan on moving my op to a location with wye 120/208 3-phase power. Problem is, I'm used to wiring my 240v 8 1000w light timer on single phase. My ballasts are multi-tap and I can run em on 208v but I'm uncertain if it will be a problem to use with my timer. It is powered with a 50a dryer cord and receptacles for my 240v ballast plugs.
If I tap 208v from my ballasts, can I still use my timer? Any ideas on 208v timers? Seems like the plugs are a different style as well.
3 Phase Power
Hello guys,
I plan on moving my op to a location with wye 120/208 3-phase power. Problem is, I'm used to wiring my 240v 8 1000w light timer on single phase. My ballasts are multi-tap and I can run em on 208v but I'm uncertain if it will be a problem to use with my timer. It is powered with a 50a dryer cord and receptacles for my 240v ballast plugs.
If I tap 208v from my ballasts, can I still use my timer? Any ideas on 208v timers? Seems like the plugs are a different style as well.
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Do you have a model/manufacturer, etc for the timer?
First, I have virtually no experience with 208, so if anyone has a better answer, holler.
Unless the components in the timer (any relay coils, the timer motor, etc) specify dual usage, I wouldn't try it. 208 is roughly 15% lower voltage than 240, which is way into the danger territory. Resistive loads, like heater coils (not the heater motor) should be fine, but would put out less heat. If the controls are all 120v, then it should be workable other than the problem below.
Using a single-phase controller on three-phase isn't going to give you the benefit of having three-phase and will give you very unbalanced loading since it will put all of the load onto two of the three phases.
A quick search doesn't show any 208-specific single-phase plug configurations. There are different ones for 125, 250, 277, and 480, and three-phase ones for 120/208 specifically (4-and 5-wire devices), but a ballast wouldn't take a three-phase plug since it is a single-phase device.
Sorry I can't be of more help. If you can provide more information on the controller, I may be able to fill in some gaps.
First, I have virtually no experience with 208, so if anyone has a better answer, holler.
Unless the components in the timer (any relay coils, the timer motor, etc) specify dual usage, I wouldn't try it. 208 is roughly 15% lower voltage than 240, which is way into the danger territory. Resistive loads, like heater coils (not the heater motor) should be fine, but would put out less heat. If the controls are all 120v, then it should be workable other than the problem below.
Using a single-phase controller on three-phase isn't going to give you the benefit of having three-phase and will give you very unbalanced loading since it will put all of the load onto two of the three phases.
A quick search doesn't show any 208-specific single-phase plug configurations. There are different ones for 125, 250, 277, and 480, and three-phase ones for 120/208 specifically (4-and 5-wire devices), but a ballast wouldn't take a three-phase plug since it is a single-phase device.
Sorry I can't be of more help. If you can provide more information on the controller, I may be able to fill in some gaps.
T
TwinTurboGuy
I just checked if any suppliers still have that timer in stock, but it has been quite some time. It was one of those old custom 50 amp panel timers with a 50amp dryer cord. There isn't much to it really, it was powered by a 50 amp dryer cord to a panel that has a built in timer.
Two 20 amp breakers at 240v for lights and one 120v 10 amp receptacle to power the timer and any other fans. I was assuming I can run 208v given that only the gauge of the wires are different. But I'm not too sure about that. And I'm not too sure about running 240v plugs and receptacles to power my ballasts tapped at 208v.
If that is the case, how is it that many of these commercial grow warehouses power so many lights on 3-phase power? And how are they all timed? I'm thinking that the ballasts are hard wired to a panel at 208v with some timer? I'm a little bit confused.
Two 20 amp breakers at 240v for lights and one 120v 10 amp receptacle to power the timer and any other fans. I was assuming I can run 208v given that only the gauge of the wires are different. But I'm not too sure about that. And I'm not too sure about running 240v plugs and receptacles to power my ballasts tapped at 208v.
If that is the case, how is it that many of these commercial grow warehouses power so many lights on 3-phase power? And how are they all timed? I'm thinking that the ballasts are hard wired to a panel at 208v with some timer? I'm a little bit confused.
208/120 works the same way as 480/277. Reference the 3 phases as X, Y & Z. The issue is balancing the 208 load (or nearly so) between the 3. You're not really using the power as 3 phase, as in a motor, but rather as 3 parallel single phase circuits. X-Y, X-Z, and Y-Z, each at 208V. Any phase can be used to supply 120V against the neutral. 240V receptacles can be used at 208V but should be labeled as 208V.
A 120V timer, 3 phase breaker and 3 phase contactor w/ 120V coil will serve your purposes. Use any phase through the breaker to the timer to neutral as the 120 control voltage, also to power any 120V receptacles. Where the power exits the contactor, you wire it the same way as 240V, just as 3 different circuits. X-Y is one, X-Z & Y-Z are the others. Put three 208 receptacles on 2 of the legs, 2 on the other, use the least loaded phase to run any 120V timed accessories against the neutral using 120V receptacles. Or use another single phase breaker to create 120V against the neutral for the timer & accessories. You can also use a single phase timer controlled relay for 120V accessories.
Sketch it out on paper to get a better understanding. If you use a 20A 3 phase breaker, you can use #12 wire & 20A receptacles, although you'll be pushing it a little hard at 80-85% of rated load. Or use two 3 phase breakers & contactors in parallel with receptacles on each.
I hope that's helpful.
A 120V timer, 3 phase breaker and 3 phase contactor w/ 120V coil will serve your purposes. Use any phase through the breaker to the timer to neutral as the 120 control voltage, also to power any 120V receptacles. Where the power exits the contactor, you wire it the same way as 240V, just as 3 different circuits. X-Y is one, X-Z & Y-Z are the others. Put three 208 receptacles on 2 of the legs, 2 on the other, use the least loaded phase to run any 120V timed accessories against the neutral using 120V receptacles. Or use another single phase breaker to create 120V against the neutral for the timer & accessories. You can also use a single phase timer controlled relay for 120V accessories.
Sketch it out on paper to get a better understanding. If you use a 20A 3 phase breaker, you can use #12 wire & 20A receptacles, although you'll be pushing it a little hard at 80-85% of rated load. Or use two 3 phase breakers & contactors in parallel with receptacles on each.
I hope that's helpful.
Thanks Jhhnn, that all makes sense. It's interesting that NEMA has never come up with a specific plug configuration for 208. You didn't address the issue of whether or not any 240v control components (if present) could be used on 208 - the best answer I can find from a search is "sometimes". Apparently it is pretty common for the actual voltage on 208 to be up near 215 or so, and 240v controls "should" work "ok" on that voltage. If the voltage is lower than nominal, then it "might" be a problem.
I did find a funny quote when I was looking - "90% of the electricians say "it should work fine". 100% of the lawyers said "was the device listed for the voltage, and was the listed voltage used?"".
TTG - your timer panel would need a significant rework to take advantage of 3-phase power. If the timer is 120v, it could be re-used. If it is 240v, I would change it out. The feed wiring should be changed out to a 3-phase arrangement and fed into 3-phase breakers and contactors and the load balanced closely as Jhhnn described.
Regarding your question about 3-phase warehouses, there are several different 3-phase voltages/configurations. Most of my experience is with 480v delta, which is a 3-wire system, no neutral and thus no lower voltages associated with it. There is 480v wye, which is 4-wire, has a neutral and yields 277v between the hot legs and the neutral. Then there is the 208 system that you have. All of them are going to take a significantly different control scheme than the single-phase systems that you have used in the past.
I did find a funny quote when I was looking - "90% of the electricians say "it should work fine". 100% of the lawyers said "was the device listed for the voltage, and was the listed voltage used?"".
TTG - your timer panel would need a significant rework to take advantage of 3-phase power. If the timer is 120v, it could be re-used. If it is 240v, I would change it out. The feed wiring should be changed out to a 3-phase arrangement and fed into 3-phase breakers and contactors and the load balanced closely as Jhhnn described.
Regarding your question about 3-phase warehouses, there are several different 3-phase voltages/configurations. Most of my experience is with 480v delta, which is a 3-wire system, no neutral and thus no lower voltages associated with it. There is 480v wye, which is 4-wire, has a neutral and yields 277v between the hot legs and the neutral. Then there is the 208 system that you have. All of them are going to take a significantly different control scheme than the single-phase systems that you have used in the past.
Thanks for the compliment, rives. 208 wye configurations are very common in med sized A/C applications like strip malls & small office buildings. Current requirements vs 240V single phase systems are much lower.
I suspect that really large warehouse grows fire the lights in banks, like big office buildings. The timer signals the system to start, and some lights come on immediately. the same timer operates on-delay relays that control more contactors for more banks. The delays can be quite small, no more than a few seconds which limits in-rush current to only a few inductive loads of any kind. Too much inrush current all at once is hard on the equipment, even the power company's equipment and can cause momentary brown-outs & equipment failure in the local grid.
Your answer about "some" 240V equipment working well at 208V is spot on. With 208 wye systems, the presence of a neutral means there's no point in taking chances when 120V equipment is cheap & readily available.
I suspect that really large warehouse grows fire the lights in banks, like big office buildings. The timer signals the system to start, and some lights come on immediately. the same timer operates on-delay relays that control more contactors for more banks. The delays can be quite small, no more than a few seconds which limits in-rush current to only a few inductive loads of any kind. Too much inrush current all at once is hard on the equipment, even the power company's equipment and can cause momentary brown-outs & equipment failure in the local grid.
Your answer about "some" 240V equipment working well at 208V is spot on. With 208 wye systems, the presence of a neutral means there's no point in taking chances when 120V equipment is cheap & readily available.
Okay so I got a little issue hear... Couple days ago I junped a 12/2 from my bathroom GFI which was 1 wire line only and loaded off into my room. Just to a regular 20A duplex receptacle. When i put the plug tester in its reading "open ground" . All connections are tight... Is there a chance that the homerun in the panel is not grounded properly? If so that SUCKS cause my landlord lives in my home "2 family" and I don't have access to the panel... Any input guys? I really need this circuit... Not for lighting but for some inline fans and whatnot..
No good either spot rives. Ive djsconnected the load and tested same thing.installed a new GFCI and also getting the same reading
If you have a voltage tester, you can read from the hot wire to the ground in the bathroom and you should get 120v (the same as reading from the hot to the neutral), and if you have an ohmmeter, you can read between the neutral and the ground and you should get a very low resistance reading.
A continuity tester won't read voltage. What are you reading between?
I might be using the wrong term.. Handheld device.. 2 seperate probes... Starts vibrating and showing 120V/240V, or 600V depending one what your testing it on.
Well, the good news is that a GFCI will still function without a ground connection. You won't have the benefit of the ground, whose primary function is to insure that the current skyrockets in case of a ground fault, thus tripping the breaker, but the GFCI will trip on low-level faults where you are doing the 60-cycle shuffle on the other end.
The problem may not be at that the panel - if there was a splice made anywhere between the two points, it could be a bad connection there. It would be worth pointing out to the landlord, though.
The problem may not be at that the panel - if there was a splice made anywhere between the two points, it could be a bad connection there. It would be worth pointing out to the landlord, though.
Rives I got a wall sconce directly above the GFCI... Snake a wore down and then over to the grow room? Go to the switch and just splice the feed threw? I know this will result in the bathroom lights being on constantly.. But i can deal with that. Just trying to figure out my best options here.
Would you say it would be safe to still use the receptacle for lower wattage equipment like a 6in Inline and maybe a few osillatings? Or nah?
Would you say it would be safe to still use the receptacle for lower wattage equipment like a 6in Inline and maybe a few osillatings? Or nah?
I'd check the grounding at the sconce before I put much effort into that one!
As I said above, the GFCI gives you all the personnel protection that you need. Grounding is just to make sure that fuses blow/breakers trip as quickly as possible. The GFCI pretty well duplicates this by shutting down the circuit if there is power going out that isn't coming back to it. Grounding is a relatively recent development in electrical history.
If the sconce grounding is intact and it is directly above the GFCI, can you snake a ground down to the GFCI from there?
As I said above, the GFCI gives you all the personnel protection that you need. Grounding is just to make sure that fuses blow/breakers trip as quickly as possible. The GFCI pretty well duplicates this by shutting down the circuit if there is power going out that isn't coming back to it. Grounding is a relatively recent development in electrical history.
If the sconce grounding is intact and it is directly above the GFCI, can you snake a ground down to the GFCI from there?
