UPS sizing for HID lighting load

[Jasonarc]

Is there any information on how to size an online UPS to support HID lighting loads?

HID - passive type ballasts can have inrush currents of up to 30 time the nominal current for 5-10 msec. In my particular case I have a 347/600 3phase distribution panel feeding 39 HID lights (400 watt each). The total load at steady state is approx 15 kW.
This comes to 24 amps per phase. If I turn on 1 HID light per phase, inrush currents are 34 amps per phase. This comes to a total of 34+24= 58 amps/phase.

Does this mean that I need a 60 kW UPS to support 39 HID lamps? And that's with the condition of 1 light coming on at a time per phase. In my case, as a cost saving measure, the lights are all turned off during weekend and turned on Monday morning. Any suggestions?

 

[engineermc]

YOU ARE FACING A HARD TROUBLE THERE IS TWO/THREE SOLUTION TO THIS PROBLEM.
1. INCREASING CAPACITY OF UPS. WHICH IS NOT A GOOD
SOLUTION A COSTLY APPROCH.
2. GET UPS SYSTEM WITH STATIC BY PASS HAVING AUTO BY- DIRECTIONAL TRANSFER, IF OVER LOAD IS SENSE LET LOAD BE TRANSFER TO BY PASS D.G. SUPPLY/ AC MAINS.
3.USE NTC AT THE PLUG OF HID.[ NOR ENGINEERING SOLN. BUT STILL TEMP. SOLN.]
4. USE DIMMER AT THE OUTPUT SUPPLY OF UPS, SITCH ON ALL LIGHT, INCREASE DIMMER VOLAGE.[LOCAL TECH. METHOD]
5. BUY UPS WITH CREAST FACTOR MORE THAN 10.

FROM
EX- AIRCRFAT ENGINEER
MUKESH CHAUHAN

 

[dydt]

hi...
one approach to deal with this type of inrush is use a UPS with static bypass...how?..while on static bypass turn on the loads gradually ..when all the loads are ON switch from bypass to inverter...since your utility and inverter is in sync mode you should have no gap at all...if you experienced any fault on your load the load will just swicth back from inverter to the bypass (utility)..

...most 5kva UPS and up have static bypass..consult your UPS manufacturer for proper sizing..

dydt

 

[busbar]

Talk to/get quotes from some UPS vendors. It's likely they have addressed the matter before. A smaller 600Y/347-rated UPS is probably not an off-the-shelf item, requiring a semi-custom unit at any rate. IEEE std 446 §3.2 may bear review.