80kVA UPS Load Curve

[Anonymous user]

I have an 80kVA UPS which will be loaded gradually whilst our upstream supply network is being upgraded.

To start, the UPS will be loaded to 25%. I would like to know what current on the input side the UPS will be drawing from my mains. This load will be gradually increased over time to 50%. I have been told there is a load curve that I can use to estimate my input currents but do not find it anywhere. Can anyone help me please?

The UPS is rated for 150A input whilst supplying the full 80kVA load.

[cmarler_apc]

Hi there Matso,

Please respond to this forum thread with some additional information. The specific information I need to form an intelligent response to your question is the part number or model of the UPS you are referring to. Is it a Silcon 80KVA UPS? Is it a Symettra PX UPS? Did you buy this as part of an InfraStruXure solution? What is the ISX solution number on your order? How old is this UPS? What is the incoming voltage of the UPS? What is the output voltage? What is the part number or model number of the PDU (Power Distribution Unit) supplying incoming electrical service to the UPS? ..and most importantly, what is the power factor of the load connected to the output of the UPS. Is it 1:1power factor corrected switched mode power supplies of computing/network equipment manufactured after 2003? I ask all these questions because different models of UPS have different input current draws for different output current draws, based on the efficiency curves of the UPS at different load levels and the power factor of the electrical load. Trust me, I'm not just asking technical questions you can't answer just to avoid giving you an answer. I love giving people answers they can use.

I'll check back later to see your response.

All the best!

-Chuck

[Anonymous user]

Hi Chuck,

Here's the info you had requested:

1. The part number or model of the UPS you are referring to.
Model SYCF80KH

2. Is it a Silcon 80KVA UPS? Is it a Symettra PX UPS?
Symmetra PX 10-80kW 3x400/230V

3. Did you buy this as part of an InfraStruXure solution?
I'm only involved in supplying power to the UPS and conecting the load. Another department ordered the unit.

4. What is the ISX solution number on your order?
PDU ISX Number ISX519605-002

5. How old is this UPS?
NEW

6. What is the incoming voltage of the UPS?
400V

7. What is the output voltage?
230V

8. What is the part number or model number of the PDU (Power Distribution Unit) supplying incoming electrical service to the UPS?
PSX-PDU239V#468110
Serial No: DF0804010008

9. What is the power factor of the load connected to the output of the UPS. Is it 1:1power factor corrected switched mode power supplies of computing/network equipment manufactured after 2003?
The load is a number of IT Servers, some old and others new.

Hope this helps.

[cmarler_apc]

Thanks Matso,
If you have it up and running, the PDU front panel power view display should show you what your phase current draw is on incoming line conditions, based on the incoming voltage.

Assuming a 97% efficiency of the PDU transformer, it has Nominal Current draw of 116A and a Maximum Current draw of 144A.
Assuming you have nominal 400V input, during normal operation for 3 phase current draw on the mains,
at 25% load you can expect to draw approximately on the mains input 35 amps
at 50% load you can expect to draw approximately on the mains input 70 amps

Main service disconnect must be sized at 200A

the manuals are at
UPS Site Prep Manual --> http://www.apcmedia.com/salestools/ASTE-6Z4KNN_R0_EN.pdf
PDU Manual --> http://www.apcmedia.com/salestools/ASTE-6YWKJ5_R0_EN.pdf

[Anonymous user]

Hi Chuck,

Thanks for your response last time.

My new question:

The UPS was commissioned in the early hours of this morning. We however have one problem, one of the Intelligent Modules (RIM) is faulty.

My problem is that we need the UPS to take load right away. Can the UPS be able to work with just one intelligent module? If the remaining IM also goes faulty, will the UPS be able to go to Static By-pass and not let the load to be dropped?

As always, your speedy, considered respeonse will be highly appreciated.

Thank you

Matsobane

[cmarler_apc · Accepted solution]

Congratulations, Matso! You picked a fine unit. I'm sorry if this reply is late. I didn't log on to check the forums until the weekend.

The Redundant intelligent module (RIM) is there for redundancy, and the main intelligence module (MIM) will work without it. The UPS can take load right away, so no worries there.

Your load will not drop, even if the remaining intelligence module goes faulty. Don't worry, your UPS will work fine. The static bypass will switch over if there is a problem with the UPS and it can't carry the load, without any switching transients that will affect the load.

good luck!

-Chuck