Hi there. I'm after some advice please, if anyone can help. I'm in the UK by the way.
We have a small (but business important) data centre with 6 racks of servers in it.
I'm looking to price up relocating this, and as part of this exercise, have been presented two options to consider on emergency power;
a) Having a UPS that runs for about 30 minutes maximum, with a standby generator on-site, designed and fulled for several days running (i.e. UPS just runs long enough to get generator up) or
b) A UPS than can run for 24 hours, with a 24 hour call off contract on a plug-in generator. (removes the need for an on-site generator)
What are peoples views on the relative costs of each option please, and also whether there are any other key factors that significantly make one option beter than the other ?
Think of all the plausible reasons your generator delivery guy might not be able to make it to your site before your batteries run out and put a price on those scenarios. Don't forget to price out the purchase and replacement costs of batteries needed to run your power and cooling for 24 hours. With just-in-time generator delivery, you'll need the infrastructure (transfer switch, alternate electrical feeders, parking spot) for a generator, anyway, so your savings will only be generator purchase and maintenance costs. I think a small generator of your own will turn out to be cheap insurance.
Also, 30 minutes is too long for automatic transfer to a standby generator; 5-10 minutes should be plenty.
It’s always a good idea to present management with at least 3 options, that way they think they are making a decision. This is called the goldilocks approach, one is too big, one is too small and one is just right. You just have to ensure that the options you don’t want them to select are either too expensive or place the business at an unacceptable risk.
Definitely recommending 5-10 min UPS in combination with on-site generators. Even with the best UPS systems despite best battery monitoring systems you actually never know how long the batteries are going to last...plus all the concerns that Ken was mentioning.