How to Calculate voltage drop ??

[Service Engineer]

So design and calculation is surely an important part, of the installation of security systems?

Design YES, Calculation ... ? Sadly NO.

To be honest most companies seem to allow extra PSU`s in with the costing, rather than bother estimating possible voltage drops. For really long data runs we always use belden even if its not specified, and thats another kettle of fish alltogether.

I can usually just have a look round site and determine how many psu`s and where i want to position them in a few minutes. Sadly the interconnection of them all isnt always soo simple..

[Guest]

Design YES, Calculation ... ? Sadly NO.

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Here it usually goes like:

Design NO

Calculation NO

Sadly? NO

I have got many good customers after solving these Design and Calculation problems.

One national once sold a system that I knew couldn't work without bigger battery and an extra PSU. It was easier to take over the site than take a candy from a kid.

[jb-eye]

Design YES, Calculation ... ? Sadly NO.

I can usually just have a look round site and determine how many psu`s and where i want to position them in a few minutes.

41736[/snapback]

Sadly i have to agree. This is the same as lets say the experienced plumber who doesn’t need the mears calculator to choose what size radiator to install in any given room. He just knows what will or wont work. The new methodology is we want the calcs to prove it will work. So give that man asking the question a pat on the back we may all learn something from his post. Although i doubt we will ever be likely to use it.

Jef

[Guest]

if you're quoting a big job and you guess the amount of PSU's needed you might lose it because you added few too much to be sure it works.

OR there isn't enough cores for power needed.. Then you add extra PSU's or pull the cable again..

Ofcourse small and medium size installations are quite clear what comes to PSU's and cable sizes.