In article ,
"Eigenvector" wrote:

I can't find a good solid ruling for this one.

That's about to change. Read on...

Are phone lines grounded locally at the house?

Yes.

More accurately, the "protector unit" for the service is connected to an earth
ground. 14-gauge used to be the norm. 12 was used for years. It's now
10-gauge.

The configuration at my house has the main phone line coming off the pole,
down to a junction box, where 2 phone lines leave and a single ground wire
connects to the cold water plumbing.

That sounds right. If done to BSP (old Bell System Practice) specification,
there should be a tag attached to the ground connection at the electrode
(water pipe, ground rod, etc). It says something to the effect: On pain of
death, thou shalt not remove the ground. It is enforced by the same thugs
that enforce the mattress tag removal ban. g

I can't find any definite answers

Until now...

as to whether or not that ground wire is required

It is.

desired

Yes.

or useless.

Only until a direct, or near-direct, lightning strike.

The intent is on replacing the whole setup with CAT 5E

It doesn't make sense to connect Cat 5e wire to a "Cat 2-1/2" network. Cat 5e
works fine for POTS (Plain Old Telephone Service) but is certainly overkill.
It's NETWORKING wire (ethernet, yammer, yammer).

(seeing how it's just as cheap as CAT 3 or phone cable

Uh, Cat 3 *IS* phone cable.

I don't know if I need to keep the ground wire.

You need to KEEP IT.

It looks like pretty standard 14 gauge wire, in a grey sheath.

If re-doing the system, I'd go 10-gauge, or at least 12.

I have encountered MANY services where the ground wire had NEVER been
connected, some as old as 20-25 years. I declined to ask the customer if they
had had to replace much/any of their equipment over the years.

I have found services bearing the above-mentioned tag with the ground clamp
(and tag) "flapping in the breeze" (disconnected). Telephony gets no respect
at all.

The "protector" at the phone entrance is NOT designed to clamp most surges -
just the *HUGE* ones, like those delivered with a direct/near-direct lightning
strike or a power line coming down across a phone cable or drop.

I once encountered an old (restored, fine) farmhouse that took a direct strike
of lightning. The charge blew the protector housing off the outside of the
home. Half of the housing was 50-feet away. I never found the other half.
On the inside of the home, the bolt blew a 2-ft gaping hole in the lathe and
plaster as it passed between a phone jack and electrical outlet across the
living room.

The charge travelled along the underground "drop" (buried service wire) about
250-ft out to the road. There it blew apart a 25-pair splice module,
interrupting service to about 20 subscribers beyond.

This protector WAS grounded, for all the good it did. With a direct strike of
lightning, ALL bets are off.

You want your protector well grounded. Trust me.
--

JR

Climb poles and dig holes
Have staplegun, will travel