Forum Discussion

Tutor

Aug 28, 2020

Nighthawk cm1100 has voltage coming out of cable line

I have had two CM1100 routers with the same issue. My cable line coming from my ISP keeps burning up and ISP says I have electrical issues (open neutral on my electrical) Electrician and electrical ut...

cgsfromkc

Tutor

Aug 29, 2020

I will try with the resistor if I can find one around my bench.

The jacket on both sides of the ground block is burned up. Although it looks like the side toward the utility pole is burned up more.

I have the ISP tech scheduled for Saturday. Hopefully they will figure it out this time. I will have them redo the entire line from the utility pole to my house, as well as, install a separate ground rod as the electric company suggested.

My_Username

Apprentice

Aug 29, 2020

Taking the cable system to the same ground as the utility should yield minimum voltage between cable and utility grounds. That said two ground rods should work fine as well. I don't believe at all that the modem could be causing this. It's good you have someone coming out.

I am a retired electrical engineer having worked in the switchmode power conversion field for 40 years. Voltages to 30kV, currents to 6 kA. Not on the same device. :) Anyway - I have seen a few ground problems.

cgsfromkc
Tutor
Aug 31, 2020
Just wanted to give an update. Spectrum tech came out and replaced the line from the utility pole to the house. He said that they never install a ground rod and that they tie into the electrical ground. He is hopeful that what the electric utility did at the pole will take care of the issue.

I will see in about 3 to 4 months if it happens again.

Thanks for all the help.
- FURRYe38
  Guru - Experienced User
  Aug 31, 2020
  Sounds good. Hopefully you won't. :smileywink: