UPS Nightmare!

What do want to acomplish? Keep the system up just long enough to shut down safely? Keep working through a certain period of time then shut down? (Say you have frequent five to fifteen minute outages, then twenty five minutes of autonomy will make shut down unnessary for most cases) Allow mission critical services to continue uninterupted?

Your answer to this question is basis for deciding what setup is best.

Next how many devices in how big an area do you have to protect?

I will give you an example: in one factory where I worked we had 3 to 10 outages of 5 minutes or less every week. As well as outages of up to one hour 2 to 3 times per month. The tremendous load placed on the supply network by the monster electric motors in the production area also tend to bring the voltage level down to brown out levels several times a day.

There were 50 clients and 6 servers with a future provission of 75 clients and 10 servers. All assets were relatively close and in two buildings.The solution I sold was to protect all clients and servers for a minimum of 1 hour under normal loads and the servers alone for 6 to 8 hours. Additionally, the system had to keep the phone system powered for 48 hours.
We installed dedicated wiringto isolate the computers and fax machines from other electrical devices (a good idea since vacuums, drills, and other electrical devices can cause unwanted problems for electronics.)

Next we installed a 45KVA UPS and additional batteries to provided 120KW-hours of power. The batteries cost more than the UPS! But the result was that we went from up to 50(!!) forced shut downs per month to 4 in the first six months.

Another solution would have been to add a diesel powered generator. But theadditional maintenace costs ruled it out. The UPS and batteries are virtually maintenance free.

This is a great site to help you.

Go to www.apc.com and select PRODUCTS.

Under PRODUCT LIST BY CATEGORY, there is a HELP ME CHOOSE button.

Once you click on it, you can select the NETWORKING link and it will walk you through what type of equipment you need to power support for. If you want you can even specify what brand switches, etc and the type of outlets.

This will help you select the proper uptime for your equipment and any other specs you are looking for.

I would like to thank u all for your advice but what i would like to have it at least a 20 minutes up time for my equipments ( that would be the maximun time I could tolerate before the maintenance guys could make the generator running).& to help u better guide me I have the list of my equipments down.

2 cisco routers
1 multiplexer
1 24 port switch
5 24 port hub
2 8 port hub
1 16 port hub
1 big (old) modular lattis hub
5 modems
& to make my life more easier the hubs are of differentbrands.Don't ask me why the old IS guy had just left when i came around.By the way i have already UPS on my Server's

Thanks again & be waiting for your advices
WMW

The first step is to calculate the VA of your equipment. On the equipment it should tell you the voltage and amperage. Multiply them and you'll get the VA. If only watts are listed, multiply watts X 1.4 to get the VA. Lets assume it totals 408VA. First, be aware that this is the maximum VA that these products will run at, and they usually never approach that.

APC tells you in its product description of the Backup Pro 420 that the typical run time is 17 minutes at half load. So we assume that at full load it is 8 min. and 30 sec. By that calculation you would need a UPS of 1000 VA in order to last 20 minutes.

However, you cannot make those assumptions. There are too many variables involved such as the age of the batteries, theactual power being consumed, and the manufacturers own claims. For example, maybe an APC BackUPS 1000 VA won't really run at 420 VA for 20 minutes, but only 17 minutes.

Your best bet is to contact APC directly, tell them that you have X equipment whose maximum VA is Y and you want that equipment to be able to run for Z minutes, and see what they recommend.

WMW,

Be very careful with APC. It may not be obvious but you need full line interactive UPS's such as Liebert GXT's. APC's, at least all of the smaller ones, work on the premise that when they detect a defficiency in voltage, they will make up the difference.
Conversely, in the event of too much voltage, they try as fast as they can to clamp down on the voltage. The problem is they aren't fast enough.

A full line interactive UPS supplies all power from battery (cleaned) and uses the line current to replenish the batteries. There is NO direct connection between the line current and the equipment.

I picked up in your question that there is a generator is your infrastructure. Have you run your servers on the generator's power? If the power from the utilities grid is "dirty", that's nothing compared to a generator output. If the UPS's on your servers aren't full line interactive, then you may want to considwer recyling them for some of the hubs? etc. that hopefully won't be as sensitive to dirty power, and use the new GXT's or Matrix's or Symmetra for the servers.

Yes, you will have to calculate the wattage requirements as outlined in answer above, but keep in mind the following additional gotchas:

Don't forget your KVM and at least one monitor. Also make sure that no one plugs a laser printer somehow into the UPS system. I've seen that happen especially where there is a separate distribution panel (a centralized solution). The heating element in a laser printerwill suck the amps right out of any UPS.

Good Luck,

Bruce Freilich
MCSE, A+

As a person that maintains several UPS systems (1 is rated at 2400 Amp Hours) compiling the above answers togather comes very close. You need:

1. Total MAXIMUM current draw.

2. Normal total power outages.

3. An idea of the normal voltage supplied to the systems (at least hourly) on at least a one week period. This will determine how stable the power is.

4. If system is monitored, your (or tech) normal response time.

5. If system is not monitored give at least 24 hours backup time.

Results determine:

1. Unstable power - use battery filtered UPS.

2. Power problems (extended outages, no generator) - Large central UPS.

3. Total minimum required UPS supplied power (@120% of max).

4. How long could the server be down before it impacts the company?

5. What you want or need to accomplish drives what type of UPS system you want/need.

BTW - Equipment type does not drive the system power requirements, MAX current rating (on the UL label) does!

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