------------Basic telco wiring color code----------------
stinger
I am very new to this group so this may have been mentioned before.
If this is the case, please excuse me......
pair / twisted (new style) / Quad-JKT (old style)
1 W/blue Blue/w Green / Red
2 W/org Org/w Black / Yellow
3 W/green Green/w White / Blue
4 W/brown Brown/w Gray / Orange*
5 W/slate Slate /w -------/------------
*note :
The fourth pair may vary between cable vendors.
Also, the polarity between the primary** color and the secondary**
color does not matter in the case of ISDN, T1 or other "digital"
equipment. Basically, it is a stream of 1's and 0's. " Analog" devices
use a type of voltage so in older equipment it was necessary to have
proper polarity. Some old telephones cant break dial tone if it is
reversed. Most new analog equipment does't care anymore.
**note :
Primary = 1st color in a pair [example-- WHITE with a blue stripe]
Secondary = 2nd color in a pair [example-- BLUE with a white stripe]
There are only ten colors in the telco cables. Even the 25 pair
cables. You have 5 primary colors : WHITE , RED , BLACK , YELLOW ,
VIOLET. Then there are 5 secondary colors : BLUE , ORANGE , GREEN ,
BROWN , SLATE . If you follow the previous chart using the other
primary colors in the order mentioned, you know about 80% of what a
typical residential telephone man /woman knows.
Also note the different grades of cable.You may here of CAT2, CAT3,
CAT5 and others. All this means is that the cable is rated as
"category 2, 3 ,4 or 5". If you look at the individual pairs closely
you can see the difference in how many twist per foot there is. CAT 3
will not be wound as tight as CAT5. The more twist to the cable, the
less interference it will pick up from your electrical wiring and
such. The better the grade the farther you can transmit a clean
signal. You might transmit clean 200' on CAT2 but you could go 350'
using CAT5.
If you haven't guessed I am a telephone tech with 14 years installing
customer equipment such as Video Conf, PABX (mostly MITEL ) VRU's ,
IVR's and a boat load of other devices. Most of this uses fiber nets ,
T1's and ISDN. Don't get me wrong. I'm not trying to brag about any of
this. It is an ever changing world and I learn something new every
day. I just wanted to give a little info on understanding basic telco
wiring.
Stinger---------->>>
Lyn Grunze
I think there are probably a lot of us who appreciate the basics and
beyond from time to time. While I have dabbled more than I should at
telephone, electric, and X-10 stuff around the house and I have my old
air force electronics training for basics, it's always good to have a
short primer for reference.
I have waited since October for my ISDN line and have gained a wealth of
information from this group in the interim. I am always amazed at how
unselfish you "experts" are in sharing your knowledge and you should
know that I for one feel much more comfortable when venturing into the
realm of the unknown.
Many thanks!