NEW Dsl splitter technical question

I have heard reports of surge compressors causing problems for DSL.

If you are going to do it that way, it is reasonable.

I would put the surge supressor on the phone line (on the phone side of the splitter), but leave the modem unprotected. That way you avoid degrading the DSL signal. If the surge protector is any good, it should absorb enough surge energy to give partial protection to the modem. If you are unlucky, you lose a modem, but not your other equipment.

Note that there is already lightning protection in the NID (or there should be). Check that the ground wire to the NID is intact.

First, if you think a plug-in protector is doing something useful, then you read only what the manufacturer hopes you read - which is not how surge protectors work. If you think the protector will stop, block, or absorb surges, then it will also block or absorb you DSL signal. Fortunately, that is not what surge protectors do. Furthermore your phone line already has an effective type protector, provided free by Verizon.

Second, protectors for telephone must be low capacitance type. That made even more critical by DSL that operates in higher radio wave frequencies. Again, the free and installed Verizon protectors is low capacitance. The plug-in protector may only further degrade the DSL signal as well as provide no useful protection.

Third, the most common source of modem destructive transients is AC electric - not the phone line.

How protectors for ph> While awaiting Verizon to turn on the service, and looking at filters,

On Fri, 25 Mar 2005 15:58:52 -0500, royroy wrote: Many thanks for the inputs. My son (the computer engineer)had also said don't do it. I had the power to the house and panel upgraded a couple of years ago and as part of that a new electrical ground was set up according to whatever code governs it. Both the installers, and the inspector said, now have Verizon and Cox both come out and attach to the same ground point (to avoid "ground loops"?). They did. I have had no problems re blown anything since.

Sounds like the earth ground was updated to post 1990 requirements. That causes one of the three incoming AC electric wires to be sufficiently earthed. But the other two incoming wires still are not earthed. Electricians know code that is about human safety. Most have no appreciation of transistor safety. Those other two AC electric wires also must be earthed. But wires cannot be connected directly to earth - and still provide utility power. So we install a 'whole house' protector in the breaker box. It is not required for human safety but absolutely necessary for transistor safety. Sufficiently sized and competitively priced units are sold in both Home Depot and Lowes (and not in other lesser quality stores such as Sears). The AC electric 'whole house' protector does same as the telco installed protector in the NID.

That connection from each utility wire to a common earth ground is secondary protection. Also inspect your primary protection:

Most computer engineers really don't have electrical training and are typically woefully ill informed about effective computer protection. Best to let your son in on these techniques necessary for minimally sufficient transistor safety.

Does the system work? Well destructive surges occur typically about once every eight years. Frequency varies with geology and other local variations. Furthermore, if the earthing and 'whole house' protectors are properly sized, then you will never know that the system works.

royroy wrote: