ups battery backup question...

[wereef]

I want to pick up a battery backup system before the spring storm season gets here. I have been looking at different brand ups systems but don't understand how to figure out what VA/watt rating to go with.
We usually lose power durring storms and it is normal to be without power for an average of 2 hours during bad storms.
I want to power 2 maxi jet 1200 powerheads which if I am correct equals 40w total. can someone explain what rating ups would be needed to be able to get close to the 2 hour time for running these pumps? and Can you please explain how to figure this out?

Hope someone can help..thanks
Wereef

 

[cjsrch]

no clue how to do anyofthe math but i can run a test on my apc baterybackup and somthing that drawns similar power. ... now i just need to find a pump at 40 watts or a 40 watt light bulb.. anyways i got to go get ready for scuba so hopfully oyur question is awnsered properly befor i get back.. but if not

 

[FragMaster]

Dont look at it as total wattage. Thats the wrong way to set it up.
You want to find the continuous volt amp's being drawn by the total amount of equipment that will be ran off of your UPS system.
A UPS system will read total amp out put not watts. ( what I was told by an electrician.)

APMP's = watts DIVIDED by voltage
Example: 2300w divided by 120v = 19.1 AMP's. That is MAXIMUM Volt amps drawn.

Multiply your total amperage found by 50% to find continuous volt AMP's drawn.
Example: 30 amps x .50 = 15 amps continuous volt AMP's drawn.

Hope this helps.

 

[wereef]

Ok Frag,

So running the numbers here, I got...

1 Maxijet 1200 = 20watts so multiply by 2 = 40watts

40watts Divided by 120volts = .33amps
round the total to .30amps
next, take .30 amps multiplied by .50 = .15a continuous load.

So now I can look at the VA rating on a given UPS system, divide the total VA by .15amps and the total should give me a rough estimate of time in minutes that the ups will run my 2 pumps. Sound Right?

Wereef

 

[FragMaster]

.34 amps round up not down. it will give you a closer target number
of .17 amps.
I "think" most UPS systems available in small scale ( IE computer back ups. the most commonly available) will only give you mili-aphere hours
(maH) so you will need to convert that figure to mili-amperes.
.17 amperes would be 170 maH. ( times your total volt amperage ( after you have multiplied that number by 50%) by 1000 and you will have
mah. )


A battery rated at 1 amp will push 1 amp for one hour, or two amps for 1/2 an hour.
A battery rated at 4300 mili-amps will run 4300 mili-amps for 1 hour
Since you now know how to find maH you can now select te correct USP system that suits your needs.

If I have left ny steps out guys pease let me know.
I dont want to give the wrong info mistakenly.
Idid check it out on the net 1st but I want to make sure I am not forgeting a step some where in the middle.
Its been a LOOOONGggg time LOL!

 

[wereef]

ok..I'm lost again,

I now know that .17amps is 170 maH (milliampHours) for the 2 Maxijets

I choose a ups, example... 260w/420VA and do the math...

I take 420va and multiply it by .50 = 210 then divide this total by 1000 = .21

is that right? what is the .21? amp or Milliamp?

Cornfused...
wereef

 

[FragMaster]

Nope
260w divided by 120v = 2.17 ( rounded up) max. volts amperes drawn.
Now multiply 2.17 VA by 50% = 1.090 ( 1.085 rounded up) Amperes
Now multiply the amperes by 1000 toget maH = 10900 maH

The selected battery back up will run 10900 Mili-amps per hour (1.090 ampers per hour).

Now to see how long 1090 maH will run 170 maH you divide 170 into 1090
= 6.41 hours of continuous run time.


Divide the wattage by the type of voltage running from your outlet you will be using ( 120v comon house hold current.) then multiply by 50% then by 1000. divide that number into what ever number of maH battery back up your looking to buy and you know roughly how long it will run them.

 

[LA-Lawman]

remember to look at the ups output and make note that it must be a line conditoner also. if teh output is not in a stable sign wave then your powerheads will click and not function properly.

there was a blurb here about a year or so... let me see if i can find it...

 

[FragMaster]

I am glad some one else chimed in here. Its been so long I knew I had to be forgetting somtning! :lol:

 

[wereef]

Thanks again frag!

I think I got it now

I just used the 420 as a ref, didn't think it would be able to run anywhere near this long! I'm off to buy a ups!

La-law, I'll look into the conditioning also. by the way, did you ever pick up that lighthouse controler from Premium Aquatics you talked about?

I broke down and bought one after we talked about my tank. I love it!
expensive little gadget but it is working fabulously!
I run my lights,heat,and additive dosing with it!


Thanks all!
Wereef

 

[Anonymous]

remember to look at the ups output and make note that it must be a line conditoner also. if teh output is not in a stable sign wave then your powerheads will click and not function properly.

there was a blurb here about a year or so... let me see if i can find it...

Inline is what you want, with a non modified sign wave. Liebert is a great brand to seek out Most the common home use ones aren't a true sign wave, or inline.

 

[FragMaster]

No problem. Just glad I still remember all of that crap! LOL!!
If I were you I would shoot for at least a 4500 mah system.
you want one that will run your heater too.

 

[ER Man]

wereef

can you advise on the UPS you bought as I bought a TRUST 800Va and it lasted all of 5 mins with a 100w load on it. Can you supply a link if you purchased it from the web and the model etc. And most important Does it last for an hour

 

[FragMaster]

Dont look at it as total wattage. Thats the wrong way to set it up.
You want to find the continuous volt amp's being drawn by the total amount of equipment that will be ran off of your UPS system.
A UPS system will read total amp out put not watts. ( what I was told by an electrician.)

APMP's = watts DIVIDED by voltage
Example: 2300w divided by 120v = 19.1 AMP's. That is MAXIMUM Volt amps drawn.

Multiply your total amperage found by 50% to find continuous volt AMP's drawn.
Example: 30 amps x .50 = 15 amps continuous volt AMP's drawn.

Hope this helps.

.34 amps round up not down. it will give you a closer target number
of .17 amps.
I "think" most UPS systems available in small scale ( IE computer back ups. the most commonly available) will only give you mili-aphere hours
(maH) so you will need to convert that figure to mili-amperes.
.17 amperes would be 170 maH. ( times your total volt amperage ( after you have multiplied that number by 50%) by 1000 and you will have
mah. )


A battery rated at 1 amp will push 1 amp for one hour, or two amps for 1/2 an hour.
A battery rated at 4300 mili-amps will run 4300 mili-amps for 1 hour
Since you now know how to find maH you can now select te correct USP system that suits your needs.

If I have left ny steps out guys pease let me know.
I dont want to give the wrong info mistakenly.
Idid check it out on the net 1st but I want to make sure I am not forgeting a step some where in the middle.
Its been a LOOOONGggg time LOL!

 

[wereef]

Well,
Picked up a 540w APC Ups and got it hooked up to the two powerheads.
Should be enough to weather out a storm (Pun Intended) Thanks for the help Guys!

Wereef

 

[Rick357]

Bump, I was hoping I could get an update on this as I am about to purchase a UPS and run two maxi jet 1200's. Does it actually run them as long as the theoretical numbers suggest?

 

[FragMaster]

NO. If you go by the raw numbers it will not.
You MUST planfor a +\-50 % margine of error. ( I know that seems huge but thats industry standard calculation)
Buy a little larger than your intitial numbers tell you to and you should be ok.

 

[Rick357]

Ok FragMaster

I want the same performance as previously stated (two 1200's) but I am buying the 900w /1500 VA Unit, will it last over 6 hours (realistically)

I need to know because I am changing some home wiring, and obviously it is important

 

[FragMaster]

APMP's = watts DIVIDED by voltage
Example: 2300w divided by 120v = 19.1 AMP's. That is MAXIMUM Volt amps drawn.

Multiply your total volt amperes found by 50% to find continuous volt amperes drawn. (industry standard for margin of error is +\- 50%)
Example: 30 amps x .50 = 15 amps continuous volt AMP's drawn.

Add the new found 15 amperes to the original 30 amperes = 45 volt amperes drawn. Adding 50% to it will ensure you have enough power to run your equipment.
I LEFT THAT OUT IN THE ORIGNIAL POST I told you guys to step up it had been a while!! LOL!!!

To find milli-amperes multiply the final result by 1000 and you will have mili-amperes.


EDIT: some ups back up systems will only give you total wattage.
In this case just find your total wattage used by your equipment.
Multilpy that number by .5 add it to the total wattage of your equipment used. That number is what you want to shoot for.

If your equipment only gives you amperes drawn you can find volts by
Multiplying total amperes given by 120v. Example: 120 volts x 2.5 amperes = 300 watts.
The 50% rule still applies

Hope this helps!


And yes realisticly you should be fine with that a 900va system will run them for 8 plus hours.

If you dont want to do the work go to this site and chose every option
Listed for a 10 hour usage back up system.
You will crap yourself when you see how much thay want though!
Cost is usualy brand specific (ofcrouse reliabilty too)
http://www.apc.com/tools/ups_selector/index.cfm

 

[ritchie1]

My exprience with running power heads on ordinary square wave UPS is that the UPS can't run the the power heads well. My powerhead makes noises and doesn't pump water. I run my powerheads on an old smart-UPS.