2250 Console cable length

[scottvtr]

Hi all,

We need to move our consoles on site to a different building due to demolition. The issue we have is that the new home for the switchboard is 500m+ away from the PABX and we've tested a 2250 using existing cabling via an IDF and it fails. It works at the halfway stage (at the IDF) but not in the onward building.
I'm suspecting a power issue, although we have power TNs setup etc....
We know we have the correct pairs jumpered through as we've tested using an Oscillator.
Do you know if there is a limit to the distance the consoles can function?

 

[informidicate]

Per the NTP's
The M2250 attendant console has a maximum permissable loop length of 3500 ft (915 m)assuming 24 AWG(0.5 mm)wire with no bridge taps. A 15.5 dB loss at 256 kHz defines the loop length limit.

 

[acewarlock]

Done normal Digital phones work thete????

 

[johnpoole]

power only improves lamp voltage and will not push the distance.. doubling the cable pair will give you a few extra 100 meters.. but if you can't work at hlf way?

john poole
bellsouth business
columbia,sc

 

[scottvtr]

Thanks guys, it does work halfway (approx 250m) but fails at the 460-500m mark. I'm assuming by a 915m loop it means that it'll work up to about 450m in one direction?

I might try doubling up on the pairs as suggested.

 

[scottvtr]

NB. Digital phones are working fine in the far location

 

[acewarlock]

If the Digital Phones are working, then the Console should work as it is only 2 digital TN's Plus power TN's. Check your pair's as they may be bad.