200 amp 3 phase 208 volt service

[Jcomeaux21]

AMJcomeaux21, if you want meaningful answers to your questions this basic info would be very helpful.

Galaxy® Commercial 1000 watt 208-240 volt ballast can operate a 1000 watt HPS, MH or DE lamp at 50%, 75%, 100% or 110% settings. The Galaxy® Commercial ballast comes pre-wired with a Sun System® lamp cord receptacle. It is compatible with all Sun System® branded reflectors. Includes a 6 ft 240 volt power cord. Efficient >98% PF operates 1000 watt HPS/MH and DE lamps, smart start feature, fully sealed extruded aluminum housing, lightweight and quiet operation. Compliant with FCC Article 18 Part A (governs commercial use) as tested by an independent US testing lab in a true as used configuration. Operates at 72 kHz. Does this help?

 

[kwired]

It would be helpful if the op gives us a total understanding of what he is trying to do so we are not just throwing things out there. Is he looking for a feeder size? Is he looking to calculate the load of the 200 amp panel? We will need much more info but perhaps he has already gotten what he needs.

He wants to double the number of luminaires. Has not given us significant data on other loads to determine if that is possible. Though if we just look at the base of needing to supply ~ 80kVA from a 200 amp 208 three phase system - the answer is 200 amps of balanced load is slightly over 72 kVA, looking like you are short on supply before even considering other details.

 

[Jcomeaux21]

Missed this post. So you have 22 lights now + AC loads/fans and want to go to 40? You probably have room for that.

I and I think most everyone else figured you had 40 lights already looking to double that to 80.

Your loads are very well balanced tho the amp readings are lower than I'd expect; were all 22 lights + all equipment running when you took those readings?

My calculations for 40 1000W lights running simultaneously are not incorrect; that alone would pull north of 111A on a 3ph 208V service, which is much higher than your calculation of 64A, nearly double; the only thing I can think of that accounts for the difference is half the lights being on while half were off.

40 light x 4.8 amps per ballast is 192 amps split between 3 legs right?

 

[Jcomeaux21]

40 light x 4.8 amps per ballast is 192 amps split between 3 legs right?

Yes all 22 and ac and fans running that was my amp reading and yes I am trying to go to 40

 

[dkidd]

40 light x 4.8 amps per ballast is 192 amps split between 3 legs right?

The amperage is at 208 volts line to line, so the calculation is more complex.

 

[dkidd]

Galaxy® Commercial 1000 watt 208-240 volt ballast can operate a 1000 watt HPS, MH or DE lamp at 50%, 75%, 100% or 110% settings. The Galaxy® Commercial ballast comes pre-wired with a Sun System® lamp cord receptacle. It is compatible with all Sun System® branded reflectors. Includes a 6 ft 240 volt power cord. Efficient >98% PF operates 1000 watt HPS/MH and DE lamps, smart start feature, fully sealed extruded aluminum housing, lightweight and quiet operation. Compliant with FCC Article 18 Part A (governs commercial use) as tested by an independent US testing lab in a true as used configuration. Operates at 72 kHz. Does this help?

Looks like this is it.
http://www.sunsystemlights.com/shop...xy-commercial-electronic-ballast-208-240-volt

 

[JFletcher]

40 light x 4.8 amps per ballast is 192 amps split between 3 legs right?

On 3 phase, you dont divide by 3 but by the square root of 3, 1.732. Your lamps are 208V, which are line to line loads. 192/root3 = 110.85A.

Another way to figure it here is your panel size of 200A x 208V x 1.732 gives you approx 72,000W available. If you have 40,000W lighting load, that's 55.5% of the available wattage (40,000/72,000), or 111A. If all 40 run at once.

I see dkidd has posted a pic of the ballast. If those ballasts are set on the 50% setting, they'd pull roughly half their max and give you numbers much lower than I was calculating at 100%.

 

[kwired]

40 light x 4.8 amps per ballast is 192 amps split between 3 legs right?

My misunderstanding on wanting to go to 80 lights then.

You would have 192 amps if on just one pair of lines with 208 volts between them.

evenly balancing that across three phases 120 degrees apart puts you at 1.732 (square root of three) factor on how it gets divided, so each line draws 192 / 1.732 = 111 amps. Since you don't have an number of units that divides by three you will be a little off balance though

39 units does balance across three lines at 108 amps and you would have 4.8 amps more on the two lines with the 40th unit on it.

 

[Jcomeaux21]

The amperage is at 208 volts line to line, so the calculation is more complex.

Mainly what im getting at is right now running 22 lights and 7.5 tons of ac plus fans and other components at the same time my draw is 34.4 amps per phase so I should be able to add 18 more and be ok. Also let me mention I have 4 control boxes running and they support up to 40 lights.

 

[Jcomeaux21]

On 3 phase, you dont divide by 3 but by the square root of 3, 1.732. Your lamps are 208V, which are line to line loads. 192/root3 = 110.85A.

Another way to figure it here is your panel size of 200A x 208V x 1.732 gives you approx 72,000W available. If you have 40,000W lighting load, that's 55.5% of the available wattage (40,000/72,000), or 111A. If all 40 run at once.

I see dkidd has posted a pic of the ballast. If those ballasts are set on the 50% setting, they'd pull roughly half their max and give you numbers much lower than I was calculating at 100%.

Thank you very much