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#160651 - 03/04/07 09:42 AM Old phone block- wiring?
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
My home has phone wiring (on the phone company side) that is state-of-the-art 1950's technology.
To be specific, I an receiving three conductors into a 305A box.

Now, Ive had the line from the box, into the house, cut / trashed any number of times. Accident, malice, animal action ... you name it. This spring I'm looking to re-route the line in a more sheltered path.

Now ... perhaps someone could save me a lot of 'hit and miss' and tell me which wire goes where?
The wire I'll use, and the jacks in the house, will be Panduit "Cat 5", since I carry those on the truck. (Think of the cable as '3 wires and 5 spares )

Which three of the four center wires goes to which screw on the 305A block?

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#160652 - 03/04/07 12:54 PM Re: Old phone block- wiring?
hbiss Offline
Member

Registered: 12/16/03
Posts: 893
Loc: Hawthorne, NY USA
Which three of the four center wires goes to which screw on the 305A block?

You are totally confused. You only use one pair. How could you possibly wire a jack with three wires?

I have never seen 3 conductor service wire- that coming in from the pole. Perhaps what you are talking about is what your house is wired with? Is this at the protector (didn't have NIDs or demarcs back then and I don't remember what a 305A looks like). If not that is where you want to start.

Do you own a butt set? The two conductors from the street are what you are interested in.

Oh, and throw those damn CAT5 jacks away. They are not for telephones only friggin' computers! Plug your computer into one by mistake and you'll wipe out your NIC on the first ring!

-Hal



[This message has been edited by hbiss (edited 03-04-2007).]
_________________________
www.myphonetechs.com

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#160653 - 03/04/07 02:31 PM Re: Old phone block- wiring?
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
What I am callo\ing "305A" boxes are the final piece of equipment from the phone company. The only identification is the "305A" stamping in the cover. This design is, as I said, quite dated. The wires look to be #18- quite large by today's standards.

Oddly enough, the phone company assures me that they can provide me DSL over this Sputnik-era hardware. Hence the desire to be able to integrate this with the phone company.

The wire terminations are the type where you wrap the stripped wire around a screw, then tighten.

Looking at the connectors (at my end), they are identified with both "A" (AT&T) and "B" (TIA) color codes. The phone would use the middle four places.

Prior to my moving into this place, the existing phone jacks were the mid-60's style, consisting of a large plug having four large round pins, and a jack that accepted it. The previous tenant had trashed the place, cutting the wire in several places, etc.

I was able to 'jury rig' service using some Cat 5 connector and a jack ... but I figure it's past time I did things in a more professional manner. I suppose I can -once again- perform 'hit or miss' at the 305 block until something works .... but I'd much prefer something along the lines of 'the blue wire goes to the screw on the left' sort of thing.

I was just hoping someone here had the 'history' to recognize this equipment.

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#160654 - 03/04/07 03:27 PM Re: Old phone block- wiring?
dougwells Offline

Member

Registered: 05/03/03
Posts: 1228
Loc: kamloops BC Canada
I would change the rj45 jack to a rj 11 style and use the blue pair for the drop from the phone to the demarc

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#160655 - 03/04/07 03:38 PM Re: Old phone block- wiring?
hbiss Offline
Member

Registered: 12/16/03
Posts: 893
Loc: Hawthorne, NY USA
I'm quite familiar with screw or binding post terminals, they are still used today. I believe a 305A is simply a couple of busses with a bunch of screws on them to allow the connection of four or five runs to one feed. It is one pair. Three wires are not used today. If your wiring is color coded, green and red is tip and ring respectively. That's your pair. The yellow was a ground and is no longer so you can forget about it.

But this really doesn't matter, you want to get rid of all that. You want to begin your new wiring at the protector located where the service enters the house. It's either outside or in the basement. That 305A is merely a junction box. Trace the feed back to where it comes from and/or follow the service wire to see where that goes.

I've seen protectors removed, buried behind the siding by the siding guys and since they were mounted to the floor joists in the basement buried when someone decides to finish the basement ceiling.

If you don't have or can't find your protector you need to have your TELCO replace the drop and install a protector which will now include a NID (network interface device). They will connect this to a proper ground (which should be your service ground) to protect your home and equipment. The NID will have either color coded screws or a lever type connection for you to run your wiring from.

Looking at the connectors (at my end), they are identified with both "A" (AT&T) and "B" (TIA) color codes. The phone would use the middle four places.

NO! Like I said, those are 8 pin network jacks. "A" and "B" designate 568A and 568B wiring methods neither of which are applicable here. You want to use 6 pin jacks that correspond to the plugs on your telephone line cords. Use the w/bl pair, w/bl is tip, bl/w is ring.

-Hal
_________________________
www.myphonetechs.com

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#160656 - 03/04/07 04:21 PM Re: Old phone block- wiring?
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
Three wire is for selective ringing back when party lines were common. Most times you just connected the green and yellow together for single party service and went out of the Dmark red/green.
_________________________
Greg Fretwell

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#160657 - 03/04/07 04:47 PM Re: Old phone block- wiring?
WESTUPLACE Offline
Member

Registered: 03/29/04
Posts: 252
Loc: Kingwood, TX USA
I think a 305A block is an old style protector. Is a metal box about 4" wide, 6" tall and 2" thick. Several style protectors were used, most common was a round knob style or some had the screw in type. There were 3 terminals on the bottom, Tip(green) Ring (red) and ground (yellow) The gn/rd/yl cable is known as station wire. It is no longer used and in not good to used modern phone systems. Newer cable is made up of twisted pairs. The twisting prevents crosstalk between pairs and also lowers the noise and interferance. (twisting the wire makes a poor antenna) Some station wire was made with 4 conductors, a black wire was added. this was for princess phones with a lighted dial. The power for the light was supplied from a transformer (wall wart style). The yellow wire was used on phone systems that used ground start. A momentary grounding of the tip wire caused the phone to go off hook. (I am not sure on how they all worked) Ground start systems I believe are no longer used in the USA. Ground is not used. If either Tip or Ring wire is grounded you will get 60 cycle hum on the phone. Some people will try to use the 4 conductor ststion wire for 2 lines, but you will most likely have crosstalk between phone lines, and it will cause DSL or data lines to run slow. Most newer phones do not care about polarity. You can hook the 2 wires either way. Older phones would not dial and some would not ring if you got the Tip and Ring wires reversed. Newer paired cable has 1st pair Wh/Bl (tip) Bl/WH (ring) 2nd pair Wh/Or (tip)Or/Wh (ring) 3rd Pr Wh/Gn (tip) Gn/Wh (ring) 4th pr Wh/Bn (tip) Bn/Wh (ring). If you use cat 5 cable (up to 4 lines per cable) you can follow the above color code. Robert

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#160658 - 03/05/07 07:44 AM Re: Old phone block- wiring?
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
Ground start was usually used for a pay phone. When folks learned all they had to do was ground the line to get dial tone ma bell armored the handset cable, changed the design of the microphone so it was "pin proof" and glued on the caps.
_________________________
Greg Fretwell

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#160659 - 03/05/07 08:54 AM Re: Old phone block- wiring?
EV607797 Offline
Member

Registered: 10/25/06
Posts: 756
Loc: Fredericksburg, VA, USA
OK, here is a brief historical bit:

305A is just a Bell System general purpose enclosure that was made out of stamped aluminium until the 1970's. It was drilled and tapped for mounting of a variety of protectors. The 305A only had room for one protector, either a 123A (one pair) or 128A (two pair).

The older drop wire that was mentined is standard 18.5 gauge standard parallel drop wire, which is perfectly suitable to support DSL. It consists ot two copper-coated steel wires laid in a parallel plastic or neoprene rubber jacket. It is similar in appearance to heavy-duty lamp cord.

The three conductor wiring was very common for station cable runs in the 1950's. The yellow conductor was used for a ground. If you were on a party line, the "A" party had their ringers connected between the ring conductor (red) and the yellow. The "B" party was connected between the tip conductor (green) and the yellow.

You won't see this, or the need for it anymore since party lines are long gone.

Oh, by the way, ground start trunks are still very heaviliy used in the US for PBX's. They won't be fading off into the sunset too soon.

[This message has been edited by EV607797 (edited 03-05-2007).]
_________________________
---Ed---

"But the guy at Home Depot said it would work."

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#160660 - 03/05/07 06:30 PM Re: Old phone block- wiring?
hbiss Offline
Member

Registered: 12/16/03
Posts: 893
Loc: Hawthorne, NY USA
Ahh, I knew Ed would remember what a 305A is. Suttle actually makes a 305A which is as I described and is not what you have.

-Hal
_________________________
www.myphonetechs.com

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