Symmetra design question

[Anonymous user]

Greetings

I'm fairly new to the large Symmetra UPS units so bear with me. I have a few APC Netshelter cabinets and each have a Symmetra LX 8kVA. I am attempting to clean up the cabinet layouts and redistribute power evenly in these cabinets as some bad setups have come into play.

Currently in a cabinet I have a Symmetra, an AP7584 distribution PDU, that plugs into one of the phases, and from there we go to an AP7541 208V metered PDU. The other phase has a 110V metered PDU installed. Due to the way the distribution PDU was installed in the cabinet with the Symmetra, the L14-30 receptacle on the upper power module for another distribution PDU is blocked and only one of the L5-20 receptacles is available. Thus we have some secondary power plugged into a 120V PDU.

What I would like to move to is the following and could use the opinion of some other people.

I would like to take our current Symmetra’s and replace the stock power distribution panels with SYPD11 panels that have two L6-30R outputs. This would allow me to plug a 208V PDU directly into each phase of the Symmetra without having to use the distribution PDU. My understanding is that I should at least be able to plug one 208V PDU into each phase.

According to the other engineers in the department the Symmetra’s are supplied by a 208/240V – 50A circuit

My questions are:

1) Is this an acceptable approach to this since each cabinet will have its own Symmetra?
2) And since each power module will be hooked to a distribution plate with two 208V outputs instead of two 120V and one 208/240V, can the Symmetra handle two 208V PDU’s on each phase without overloading the unit?

I apologize for the long winded post and any insight will be greatly appreciated

Thanks

Brad Townsend
IT Physician Services
St Bernards Hospital

[Anonymous user]

Yes, we have three power modules installed in this chassis.

This is the current setup

SYAF8KRMT - Chassis
3 X SYPM4KP - Power Modules -------------> 204/240V - 50A Circuit ------------> Currently each power module output on the Symmetra is 2 X L5-20 (100/120V 20A) and 1 X L14-30 (120/208/2240V 30A) receptacles
2 X SYIM5 - Intel Modules
2 X SYBT4 - Battery Modules


If I understood you correctly if I replace the plate with the 2 X L5-20 and 1 X L14-3 with a plate that has just 2 X L6-30 I would still want to power just 1 X 208V PDU (AP7541) on each power module even though it has two receptacles?

Message was edited by: btownsend

[TheNotoriousKMP_apc]

Hello,

The problem lies with the following. The UPS overall is a maximum capacity 8kVA. You have N+1 redundancy with the three power modules, and with the two batteries, may have minimal runtime at full capacity.

I was assuming you had two backplates that you were looking to replace, and put PDU's on all of them. As each PDU is almost 5kVA, after 2 PDU's placed, you would be 2kVA above capacity. Therefore, if it is just one backplate that you are adding, and using only that backplate and nothing else, you can achieve the full 8kVA from both receptacles combined, and you can put 1 PDU per receptacle, but again, cannot fully load them as it would still put you at 10kVA fully loaded on the PDU's.

[Anonymous user]

With the server capacity that I have per cabinet, which is currently about 12 - 15 servers (a mix of 1U, 2U, and 5U), I shouldn't need more than two 208V PDU's (which have 18 plugs + some other specialty plugs).

Would this setup still cause a 2kVA capacity overload

1) Symmetra as configured above.
2) Replace both backplates with 2 X L6-30 plates
3) Plug 1 X 208V PDU in backplate 1, leaving the second receptacle unused.
4) Plug 1 X 208V PDU in backplate 2. leaving the second receptacle unused.

5) Balance server power similar to the following: (PS = power supply)

PDU on backplate 1...................................PDU on backplate 2

PS1--------------------------------Server1-------------------------------------PS2
PS1--------------------------------Server2-------------------------------------PS2
PS1--------------------------------Server3-------------------------------------PS2
PS1--------------------------------Server4-------------------------------------PS2

etc.?

Message was edited by: btownsend

[TheNotoriousKMP_apc]

Hello,

This setup seems ok. The only thing I would check is what the capacity of each PDU goes to if PDU1 fails over and PDU2 takes full control of the load. If the load doesn't exceed 5kVA, then you should not have a problem.

[Anonymous user]

We have been moving forward with this approach and I have another question or in this case more of a second opinion. I am horrible at describing things so I am posting a few picture links to help.

We are going to replace our stock panels on the Symmetra with 2 SYPD11 panels, these are the ones with 2 L6-30 connections.

Here is what the stock panels and wiring harness looks like:

!http://i98.photobucket.com/albums/l263/tehbrad/APC/IMG_0135.jpg!


Here is what the wiriing harness on the new panels looks like:

!http://i98.photobucket.com/albums/l263/tehbrad/APC/IMG_0132.jpg!


As you might be able to see from these pics (assuming they size right), the wiring harnesses don't match.

The chassis harness as a 5 wire connector with 3 white wires, a 4 wire connector with 4 black wires, and a 3 wire connector with 3 red wires.

The new panel wiring has a 4 wire connector with 4 black wires and a 3 wire connector with 3 white wires.

The word passed on from my power specialist at CDW was that the wiring harness wire colors don't always match up and that I should use the two connectors that match on the new panel with their matching counterparts on the chassis harness and leave the third chassis plug unused. So, just to make sure I don't mess something up, is that the way these new panels should wire in?

[TheNotoriousKMP_apc]

I think if I read correctly you're going 4 black to 4 black and 3 white to 3 white right, overlooking the red?

That sounds like the way it should be. How many receptacles did the old PDU have, that would account for the extra set of Red Wires.

[Anonymous user]

Thats the weird part. It would actually be 3 white to 3 red. The white connector on the chassis harness is actually a 5 pin connector, the new panel is still just 3 wires but only has a 3 pin connector.

Here is the stock panel:

!http://i98.photobucket.com/albums/l263/tehbrad/APC/IMG_0134.jpg!

Here is the new panel, we are essentially going from 3 receptacles to two so I can understand the reduction in cables, but logic says that the wiring should match:

!http://i98.photobucket.com/albums/l263/tehbrad/APC/IMG_0133.jpg!

[TheNotoriousKMP_apc]

Brad,

Now I understand. They changed the color coding on the harnesses, so yes, your CDW man was correct. You will have a leftover harness due to no longer having an L14-30 which was comprised of the 2 hot, neutral, and ground wires.

[Anonymous user · Accepted solution]

Greetings

I'm fairly new to the large Symmetra UPS units so bear with me. I have a few APC Netshelter cabinets and each have a Symmetra LX 8kVA. I am attempting to clean up the cabinet layouts and redistribute power evenly in these cabinets as some bad setups have come into play.

Currently in a cabinet I have a Symmetra, an AP7584 distribution PDU, that plugs into one of the phases, and from there we go to an AP7541 208V metered PDU. The other phase has a 110V metered PDU installed. Due to the way the distribution PDU was installed in the cabinet with the Symmetra, the L14-30 receptacle on the upper power module for another distribution PDU is blocked and only one of the L5-20 receptacles is available. Thus we have some secondary power plugged into a 120V PDU.

What I would like to move to is the following and could use the opinion of some other people.

I would like to take our current Symmetra’s and replace the stock power distribution panels with SYPD11 panels that have two L6-30R outputs. This would allow me to plug a 208V PDU directly into each phase of the Symmetra without having to use the distribution PDU. My understanding is that I should at least be able to plug one 208V PDU into each phase.

According to the other engineers in the department the Symmetra’s are supplied by a 208/240V – 50A circuit

My questions are:

1) Is this an acceptable approach to this since each cabinet will have its own Symmetra?
2) And since each power module will be hooked to a distribution plate with two 208V outputs instead of two 120V and one 208/240V, can the Symmetra handle two 208V PDU’s on each phase without overloading the unit?

I apologize for the long winded post and any insight will be greatly appreciated

Thanks

Brad Townsend
IT Physician Services
St Bernards Hospital