UPS Sizing

[mrbios]

Anyone any good at calculating the size of UPS you need for specific equipment?

 

I've tried messing with the APC calculator but i've no idea how accurate it'll be based on the equipment I'm using.

 

In total I've got:

6 x 1U servers (all 2 x PSUs)

2 x 2U servers (all 2 x PSUs)

4 x SANs (all 2 x PSUs)

1 x modular switch (8206zl, 2 psus)

8 x other 1u regular switches

1 x smoothwall appliance

1 x tape autoloader

1 x wireless controller

37 total power connections

 

UPS wise, most are quite old now and none of them have management cards in so they're just "dumb" currently, and i've got these models:

APC Smart UPS 5000 + 6 port extension PDU thing

2 x APC Smart UPS 3000XL

APC Smart UPS 3000 (a lot older than the other two)

 

The 3000s run off 16amp feeds and the 5000 off a 32amp feed, if i remember correctly.

 

Which is certainly enough in terms of capacity going by experience of them running after a power cut, but it's high time i actually plan it out and make it more intelligent (shut everything down when battery level is low!) as it's one area that i've never done anything about in all my time here.

 

I was thinking of replacing the 3 x 3000s with another 5000 and putting a management card in both. Which would actually save me a bit of space as well. I'd like some recommendations from someone more experienced in this area though?

[Blue_Cookeh]

I don't see UPSes as things that really need replacement. If they're still working and have enough capacity, good batteries are generally all you need. If you're looking at more space then by all means swap out your 3000s for the 5000, but definitely put the management cards in. We don't use UPSes of that size (we don't need them) but I found putting management cards in our older UPSes gave us all we needed at a fraction of the cost.

 

Run time is a difficult one since it depends on what your servers are doing, what PoE you're powering etc, but I'd look at managing it. We set ours to start powering off non-essential services earlier so we can keep things like phones and DCs running longer.

Edited March 10, 2016 by Blue_Cookeh

[PotNoodleTech]

I would recommend you replace the batteries every 3 years and the UPS's every 6 years. UPS's have plenty of items such as capacators that can degrade over time - I wouldn't run my real estate on 10 year old UPS(s).

 

I am running 2 x 3000 but my whole server cab only pulls 1500w average so that gives a nice 30 min runtime.

 

For the amount of servers you have I would be looking at the least 2 x 5000 maybe more. It depends if you want 5 minute runtime or 30.

 

Running you're UPS at 100% load not only gives you poor runtime, it puts excessive stress on the UPS and in particular the batteries during an outage - can often cause the batteries to swell / fail. IMHO aim to run at no more than 50% capacity so you get at least 15 minutes runtime.

[mrbios]

I don't see UPSes as things that really need replacement. If they're still working and have enough capacity, good batteries are generally all you need. If you're looking at more space then by all means swap out your 3000s for the 5000, but definitely put the management cards in. We don't use UPSes of that size (we don't need them) but I found putting management cards in our older UPSes gave us all we needed at a fraction of the cost.

 

Run time is a difficult one since it depends on what your servers are doing, what PoE you're powering etc, but I'd look at managing it. We set ours to start powering off non-essential services earlier so we can keep things like phones and DCs running longer.

 

Thanks they're not something i've ever looked to replace before or ever considered until now. We've just replaced batteries when they've died in the past, but 3 large UPS's taking up a quarter of a rack which is pretty much full is frustrating now as I'm also nearly at the point of being able to remove one of two racks and give us a shed load more space in the server room.

 

Obviously don't want to waste money just to reclaim a bit of space though, so it's a case of weighing up the cost vs benefit.

 

I would recommend you replace the batteries every 3 years and the UPS's every 6 years. UPS's have plenty of items such as capacators that can degrade over time - I wouldn't run my real estate on 10 year old UPS(s).

 

I am running 2 x 3000 but my whole server cab only pulls 1500w average so that gives a nice 30 min runtime.

 

For the amount of servers you have I would be looking at the least 2 x 5000 maybe more. It depends if you want 5 minute runtime or 30.

 

Running you're UPS at 100% load not only gives you poor runtime, it puts excessive stress on the UPS and in particular the batteries during an outage - can often cause the batteries to swell / fail. IMHO aim to run at no more than 50% capacity so you get at least 15 minutes runtime.

 

They last about 15 minutes currently when we have a power cut. The oldest of the 3 x 3000s is over 10 years old Replaced that batteries in it twice, but we only replace batteries currently when they actually fail. Be interesting to hear others opinions on this one as i've never heard of people proactively replacing batteries on a 3 yearly basis before.

Edited March 10, 2016 by mrbios

[twin--turbo]

Whatever you do , ensure yo I r incommer is sufficiently rated to handle the startup l pad of all the equipment.

 

I have been in the unfortunate situation where a big professional IT company failed on this more than once.

 

In one case they had a UPS with a requirement of 40A listed on the back, it was plugged into a 16A supply. This only came to light when we asked them to put in another ups and they said there was a spare 16A!!

 

On our other site the ups there was on a 32A circuit and even that tended to trip when the power came back on.