Rack PDU AP7902 - Statistics Question

[Anonymous user]

I am doing some budgeting and I would like to come up with some sort of cost of electricity associated with the equipment supported by our AP7902s. I can see from the UI they provide Amps, but in order to calculate something like kW hours I would need like a watt or volt measurement. Does anyone have any suggestions where/how I can get this kind of number? Has anyone had to do this before?

Thanks in advance!

[Anonymous user]

I am doing some budgeting and I would like to come up with some sort of cost of electricity associated with the equipment supported by our AP7902s. I can see from the UI they provide Amps, but in order to calculate something like kW hours I would need like a watt or volt measurement. Does anyone have any suggestions where/how I can get this kind of number? Has anyone had to do this before?

Thanks in advance!

[Anonymous user]

If I understand the way an ampere works, it is measured in coulombs per second. So using your example 8(120)=960w/s? Is that correct? It would then have to be converted to kWh right?

[BillP]

just to clarify, you would like to find out these measurements of the load attached to the PDU, correct? the AP7902 assumes a power factor of 1 and assumes the nominal input voltage that you are using. you can adjust some of these values via SNMP though so that you are able to calculate the kWh and kWh for your load. i honestly am not 100% how to do these calculations though. this may help? -> http://answers.yahoo.com/question/index?qid=20080102150302AAxmlnf

i would just like to indicate though, APC's New Next Gen PDUs do calculate all of this for you in real time and they measure current and input voltage to make these figures as accurate as possible.

you can check out this brochure on our metered rack pdus -> http://www.apcmedia.com/salestools/JKUR-87JM4Z_R1_EN.pdf

here is the brochure on the switched rack pdus, the replacement for the AP79xx series you have now -> http://www.apcmedia.com/salestools/JKUR-8ADRTQ_R1_EN.pdf

[upsguy_apc]

Do you have the network interface set up? You should be able to log into the Web Browser for the specific PDU you are trying to get the info for and get a current measurement. Or read the display on the front of the PDU. You could then multiply that number by the voltage of the PDU output.

So if the PDU displayed 8A and you measured the PDU as having 120VAC. This PDU would be powering 960w of load.

[upsguy_apc · Accepted solution]

For determining utility rates yes, you would want to know Kwh which at a steady state 960w instantaneous is .96kwh.


I picked a winna:... Didn't wanna bring pf into this discussion because for someone trying to get a ballpark on power usage of a small rack mount PDU they more than likely aren't breaking out a PQA to get that info. Otherwise there wouldn't be any question to how much power was being used because it would displayed on the PQA.


Note: This is just a ballpark figure and if your determining how much to charge a user then you will be safe as the actual KW load can't be any higer than Amps*Volts regardless of PF.