User's Manual

Table Of Contents
15 E1/T1 Installation Guide
292
15.7 Testing the E1/T1 Installation
If you have opted to fit a Lightning Protection Unit, it should be tested as described in Section
10.3 “Installation”.
Test the tele
coms links by performing loopback connections as described in Section 8.3.1.6
Telecoms Configuration Page”.
15.7.1
Pre-Power Testing
Before conn
ecting your E1/T1 source, check the following resistances:
Check the cable resistance between pins 3 & 6 (Green/White & Green) and 7 & 8
(Brown/White & Brown). Check against Table 47 column 2.
Che
ck the cable resistance between pins 1 & 2 (Orange/White & Orange) and 4 & 5 (Blue &
Blue/White). Check against Table 47 column 3.
Table 47 -
Resistance Table Referenced To the E1/T1 Source
CAT-5 Length (Meters) Resistance between pins
3 & 6 and pins 7 & 8
(ohms)
Resistance between pins
1 & 2 and pins 4 & 5
(ohms)
0 0.8 1.3
10 2.5 3.0
20 4.2 4.7
30 5.9 6.4
40 7.6 8.2
50 9.3 9.8
60 11.0 11.5
70 12.7 13.2
80 14.4 14.9
90 16.1 18.2
100 17.8 18.3