Clarification on definitions of terms

[Anonymous user]

Hi,
I realise that this is the ultimate noobie question (or series of questions) but I have some APC terminology and I was wondering if someone could elaborate on what they actually mean in the real world when it comes to choosing a UPS.
We have 2 Smart-APC UPSs at the moment and we plan to upgrade at least one of them. I have checked the values for the fields in Powerchute so that we might make an informed decision but the obscure definitions which I have found on the web make it difficult to decide which values we should be watching out for when choosing which UPS should be replaced. So here goes, I have included the definitions which I have located thus far.

Capacity - The UPS has a nominal maximum capacity, usually indicated by the number in its model name. In this example, it is 650 VA. The UPS will probably handle a load slightly above this figure--much the way your car doesn't stop dead when the fuel gauge hits "E"

Load - power consumed by a circuit
PC power supplies use a technique called switching to generate their DC voltages. Due to the manner in which these sorts of power supplies function, they need to have a load, meaning something that draws power from the supply, in order to function properly. A power supply that is turned on with no load attached will either fail to function or will function improperly. Better-quality supplies will detect a no-load situation and shut down, but cheap ones can be damaged. This is why you should not "test" a power supply by just plugging it in with nothing attached to it.

Load Power - Apparent Power (I'm assuming that this is also known as Load Power) is measured in volt-amperes (VA) and is the voltage on an AC system multiplied by all the current that flows in it. It is the vector sum of the active and the reactive power.
Apparent power is measured in Volt-Amps (usually kVA) Apparent Power = Voltage x Current

Load current - the current drawn by the application that is connected to the power source
If, given the technical nature of these terms, the definitions can't be broken down any further, that's no problem. Alternatively, could you let me know which terms to pay attention when choosing which unit should be replaced?
Many Thanks,
I'd really appreciate any advice on this and again, I apologize for basically asking for a class in Electricity 101 :).
Justin.

Message was edited by: justin.forde@bankers.ie

[Anonymous user]

Hi Clarkson, Winna,
Thank you very much, your advice has become My Go-to Guide when it comes to UPS systems :).
I'm doing the maths at the moment - could you tell me 2 things -

Voltage - I'm assuming that that's Input/Output Voltage and it doesn't matter which I choose since the UPS says that they're both at the same level.
Power Factor - Is there a way that I can determine this? According to Powerchute, the batteries on our UPS systems were last replaced in 2008 and 2006 so I'm assuming that the UPS itself predates these both but I don't think that I can place the UPS system in an 'older' or 'newer' category in order to determine the Power Factor from this.

Many, many thanks, once again,
Justin.

Message was edited by: justin.forde@bankers.ie

Message was edited by: justin.forde@bankers.ie

[Anonymous user · Accepted solution]

Hi,
I realise that this is the ultimate noobie question (or series of questions) but I have some APC terminology and I was wondering if someone could elaborate on what they actually mean in the real world when it comes to choosing a UPS.
We have 2 Smart-APC UPSs at the moment and we plan to upgrade at least one of them. I have checked the values for the fields in Powerchute so that we might make an informed decision but the obscure definitions which I have found on the web make it difficult to decide which values we should be watching out for when choosing which UPS should be replaced. So here goes, I have included the definitions which I have located thus far.

Capacity - The UPS has a nominal maximum capacity, usually indicated by the number in its model name. In this example, it is 650 VA. The UPS will probably handle a load slightly above this figure--much the way your car doesn't stop dead when the fuel gauge hits "E"

Load - power consumed by a circuit
PC power supplies use a technique called switching to generate their DC voltages. Due to the manner in which these sorts of power supplies function, they need to have a load, meaning something that draws power from the supply, in order to function properly. A power supply that is turned on with no load attached will either fail to function or will function improperly. Better-quality supplies will detect a no-load situation and shut down, but cheap ones can be damaged. This is why you should not "test" a power supply by just plugging it in with nothing attached to it.

Load Power - Apparent Power (I'm assuming that this is also known as Load Power) is measured in volt-amperes (VA) and is the voltage on an AC system multiplied by all the current that flows in it. It is the vector sum of the active and the reactive power.
Apparent power is measured in Volt-Amps (usually kVA) Apparent Power = Voltage x Current

Load current - the current drawn by the application that is connected to the power source
If, given the technical nature of these terms, the definitions can't be broken down any further, that's no problem. Alternatively, could you let me know which terms to pay attention when choosing which unit should be replaced?
Many Thanks,
I'd really appreciate any advice on this and again, I apologize for basically asking for a class in Electricity 101 :).
Justin.

Message was edited by: justin.forde@bankers.ie