Two SUVTP15KH4B4S in Parrallel with Dual Utility Supplies - How?

[Anonymous user]

Hi,

Sorry in advance if this question has been covered but I couldn't find something similar on the forums at the moment. We have two of these http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=SUVTP15KH4B4Scurrently one is connected and in operation and has been for a couple of years. it is a 3 phase UPS on a single utility supply powering our small server room.

The Questions:

1. We'd like to add UPS redundancy by connecting up another identical UPS in parallel or in some other way to allow a single UPS to fail but the load to continue. How might we do this, what are the options?

(Note: we only have a 10Kva load (or thereabouts) so we just need the second UPS as redundancy i.e. N+1, however we have heard it can do 2N so both are active at the same time, and in the event of failure one or the other takes the full load.)

2. We'd like to add utility power redundancy by adding another utility supply to supply both UPSes, so if a utility supply was to fail, both (or one) UPS continues to run (without shutting the servers down with PowerChute) how might this be done, what are the options?

3. How are all the servers connected to both the UPSes? I.e. how do I connect them up so that a single utility supply or single UPS failure doesn't take down all the connected equipment?

4. Otherwise, who at APC or Schneider do I need to speak to get some consultancy time to design a solution?

Thank you for any help you might have.

Thanks

Tristan

[BillP]

Hi Tristan,

I asked our EMEA support for some assistance since I am based in NAM and unfamiliar with this unit. Here is what they provided to me.

1. We'd like to add UPS redundancy by connecting up another identical UPS in parallel or in some other way to allow a single UPS to fail but the load to continue. How might we do this, what are the options?

(Note: we only have a 10Kva load (or thereabouts) so we just need the second UPS as redundancy i.e. N+1, however we have heard it can do 2N so both are active at the same time, and in the event of failure one or the other takes the full load.)

From the installation manual (http://www.apcmedia.com/salestools/AHIE-7WCHJU/AHIE-7WCHJU_R1_EN.pdf ) (page 11) a diagram shows 2 X UPS's configured in parallel:

The customer will require an additional component, the maintenance service bypass panel: SBPAR10K20H-WP. There will also be additional work involved by an APC Field Service Engineer such as removing the bypass switch from each of the UPS's in question. It should be noted that this SBP is an off the shelf solution and does not incorporate the switches (as seen above) Q1 or Q5. If the customer would prefer to have a SBP with these switches installed within the SBP, then a custom SBP can be created and the part number required is QPBL78374.....this would make wiring the installation simpler. Otherwise the Q1 & Q5 breakers will have to be provided external to the SBP and UPS.

2. We'd like to add utility power redundancy by adding another utility supply to supply both UPSes, so if a utility supply was to fail, both (or one) UPS continues to run (without shutting the servers down with PowerChute) how might this be done, what are the options?

The SUVT UPS can accommodate 2 utility supplies. Again referring to the installation manual, you can clearly see the points at which the electrical connections should be made for Mains 1 & Mains 2. In the diagram above the mains 2 is connected to the Q5B breakers. In the event of a power failure on mains 1, the UPS would go to battery operation until low DC shutdown.....that is if it is not configured to go to bypass operation when it gets to low battery. If it is configured to go to bypass when it gets to low battery then the load will be powered by mains 2 when the UPS transfers to bypass operation.

3. How are all the servers connected to both the UPSes? I.e. how do I connect them up so that a single utility supply or single UPS failure doesn't take down all the connected equipment?

The fact that the UPS's are working in parallel means that if one UPS is completely removed from the system the load will continue to be powered from the other UPS (provided the load does not exceed the capacity of the UPS in which case it would go to bypass to support it). In the diagram above, Q2A & Q2B are the output breakers on the bypass panel from each of the UPS's. If one of these is opened the load will not suffer any ill effects. Likewise if either of the UPS's fail the load will still continue to be powered by the other UPS.

4. Otherwise, who at APC or Schneider do I need to speak to get some consultancy time to design a solution?

If you feel the need to speak to somebody regarding designing a solution it is best to call our local support number (0800 2799254) who can best direct your call to either technical sales or technical support.

[Anonymous user]

Okay that's great thank you, it all seems to make more sense now.

Just a couple of points to clarify.

1. Can the whole system work with a single input to each UPS? but those single inputs come from an external switch panel which is using two inputs. I.e. there is some site switch gear in front of the UPS that switches between input 1 and input 2 (i.e whichever is live) and then always delivers a working single input to both UPSes through the maintenance bypass panel (unless a grid power failure takes both inputs out)?

The reason I ask this is we are looking to have a generator socket as another input, but this would only be temporary power supply in the event of a very long power outage, so in reality we'd want 3 inputs, where input 3 is a generator socket. Which is why I ask about having some site switching gear that is external to the maintenance bypass panel and the UPSes. We'd also be running air conditioning (not off the UPS) that we'd want to have dual input too, so it kind of points to external input switching to be required external to UPS to give us this. Then just a single input to the two UPS.

2. Yes, i'd stumbled across the maintenance service bypass panel: SBPAR10K20H-WP, didn't know these could be customised though, I couldn't find that part code: QPBL78374 for the customisation? I assume this is something we need to ask for when we order, rather than find on the website?

Also how does the maintenance service bypass panel avoid back feeding the other UPS, i.e. one UPS is active and supplying the load, the other UPS is off, how does it stop this power going back, is this done by the maintenance service bypass panel itself?

Many thanks

Tristan

[BillP · Accepted solution]

1. Can the whole system work with a single input to each UPS? but those single inputs come from an external switch panel which is using two inputs. I.e. there is some site switch gear in front of the UPS that switches between input 1 and input 2 (i.e whichever is live) and then always delivers a working single input to both UPSes through the maintenance bypass panel (unless a grid power failure takes both inputs out)?

The reason I ask this is we are looking to have a generator socket as another input, but this would only be temporary power supply in the event of a very long power outage, so in reality we'd want 3 inputs, where input 3 is a generator socket. Which is why I ask about having some site switching gear that is external to the maintenance bypass panel and the UPSes. We'd also be running air conditioning (not off the UPS) that we'd want to have dual input too, so it kind of points to external input switching to be required external to UPS to give us this. Then just a single input to the two UPS.

Yes. The UPS's come with jumpers between the bypass input and the mains input, so if you were to use only 1 source with no external bypass feed then you would leave the jumpers installed.

2. Yes, i'd stumbled across the maintenance service bypass panel: SBPAR10K20H-WP, didn't know these could be customised though, I couldn't find that part code: QPBL78374 for the customisation? I assume this is something we need to ask for when we order, rather than find on the website?

The part I actually quoted to you is a part that is put together by our configuration team in Denmark. In order to be able to purchase one of these, your sales rep will need to have a quotation created by that Danish team. No need for this step if you are purchasing an off the shelf product.

Also how does the maintenance service bypass panel avoid back feeding the other UPS, i.e. one UPS is active and supplying the load, the other UPS is off, how does it stop this power going back, is this done by the maintenance service bypass panel itself?

No. The UPS is designed in such a way that the path back through the UPS is opened in the event of a fault developing. 

Further technical information can be found here: http://www.apcmedia.com/salestools/ALEX-73YKER/ALEX-73YKER_R2_EN.pdf