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Russell H.
Russell H., Computer Repairer
Category: Computer Hardware
Satisfied Customers: 11079
Experience:  Working to keep PC-type computers working since 1988.
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I am researching UPS Backups for a mail server how can I

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I am researching UPS Backups for a mail server how can I calculate the approximate power life for my server on outage?
Customer: replied 1 month ago.
Disregard wrong section
I am Josie, a moderator for the category your question was first posted in.
Your question has been moved to the appropriate category and is open to all Experts.
There is no need to re-post or re-list your question.

Hi, thank you for contacting My name is***** will do my best to provide the right answer to your question.
The way to calculate the approximate power life (or length of time the UPS power supply will keep things running) on power outage, is to take the Watt-hour capacity figure for the UPS backup, then divide the amount of Watts demand (or load) that will be placed on it, and get the number of hours that way.

For example: you are examining a UPS backup with 400 Watt-hours capacity.

And your server, which will be the only load on it upon power failure, requires 400 Watts of power, average, continuous, or expectable load.

400 W-h / 400 W = 1 (that is, one hour, before the UPS signals shutdown to the server, if it has that signaling capability before the battery goes dead.)

(Actually, since this sort of thing is in practice less than perfect, the expectable UPS power-supplied-after-power-failure time would be more like 45 or 50 minutes, rather than a full hour.)

Let me know if you need more information, or for me to advise you as to specific details on any given example.

Before you go, please rate my answer - a five-star rating best expresses appreciation of the work I have done. (Or let me know how highly you rate my work on your question, in Reply To Expert. Thanks.)

Customer: replied 1 month ago.
Thanks Russell you have been one of the best on here. More important question. I spoke with comcast and don't always trust answers. I have a business class modem in a resident apartment. It was indicated power failure likely drops the internet also so a UPS may be useless. Was comcast accurate or do you have opinion?

As for my opinion as to power failure and Comcast service: Is the service Comcast cable, or Comcast Fiber-Optic (if there is such a thing) ?

Customer: replied 1 month ago.
Pretty sure cable i dont think it has fiber

OK. Cable service, in a power failure, is reported variously to work if their (Comcast's) equipment has a UPS, to stay on in a power failure, and to stay on only as long as their UPS lasts for their transceiver/equipment at the other end of the cable line.

So... "likely drops the internet also" is fairly accurate as a summary: it might stay on, it might stay on only a while (but not in an extended i.e. over 2 hours power failure)... and it might drop service for the duration. (Power failure vary not only in duration, but also in extent, and cable internet is a networked function ultimately, so a more widespread power failure would drop the service for the duration in all likelihood.)

I think that's a fair assessment.

Please rate my answer and my work highly - it's appreciated, as a return for my attention to your question's details. Thanks, ***** ***** a great day.

Russell H., Computer Repairer
Satisfied Customers: 11079
Experience: Working to keep PC-type computers working since 1988.
Russell H. and 7 other Computer Hardware Specialists are ready to help you
Customer: replied 1 month ago.
Great answer! Your the best.

Thank you for your praise, in hard times :) it is appreciated. And you've been a good customer to deal with. Have a great day.