SPD bonding question

[prcguy]

Thinking about the hundreds of apartment units I'll add a final comment on what I might do realizing limited access to a communications closet. First I would install a ground block on the coax before the modem and connect the ground block to the third prong of an AC plug into the nearest outlet. Each individual apartment should have its own circuit breaker panel. I would get and install both a Delta LA302 MOV type lightning arrestor across a pair of existing 20 amp breakers (one on each 120V leg of a 240V feed) that has very little use and a matching Delta CA302 surge capacitor across another pair of lightly used 20A breakers. With most light bulbs being replaced by super low current LEDs a breaker specifically for lights is a good target, or if there are unused breaker slots install new breakers just for the Delta units. Then a Jensen VRD-1FF CATV F type isolator on the modem side of the ground block.

This will place the CATV line at the same ground potential as everything in the apartment and the Delta units will lessen the chance of damage to electronic equipment from a couple thousand volt jolt. Its a few hundred $$ in parts but cheap insurance and when you move you can take the parts with you. If there is a huge spike on the AC lines during a strike its a very short event and the Delta units will absorb the spike and usually blow the breaker, but the event will be over before the breaker trips. The Delta units should be good for many strikes, especially in a huge complex where they are just across one breaker panel out of hundreds.

Here are links to the recommended parts if interested. I've installed the Delta units in several places of mine and for friends.

Amazon.com: Delta Lightning AC Surge Arrestor - for 120/240 VAC Water Wells, 0-300 Volt AC, | LA302 : Electronics

Buy Delta Lightning AC Surge Arrestor - for 120/240 VAC Water Wells, 0-300 Volt AC, | LA302: Surge Protectors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Amazon.com: Delta CA302-R 2-Pole 125/250VAC Single Phase Surge Capacitor : Industrial & Scientific

Amazon.com: Delta CA302-R 2-Pole 125/250VAC Single Phase Surge Capacitor : Industrial & Scientific

www.amazon.com

Jensen Iso-Max VRD-1FF 75 Ohm Inline Digital CATV Isolator Hum Eliminator

Jensen Iso-Max VRD-1FF 75 Ohm Inline Digital CATV Isolator Hum EliminatorThe VRD-1FF was engineered for use with composite video systems, and is used to remove ground-loop hum and "hum bars" from signals in virtually any application. With high quality F cables, connect the VRD-1FF between your...

www.parts-express.com

 

[KevinC]

A little work and you can get the Green Gound Wire out of the outlet box and have some type of ground point.
Might not be the best but it is better than nothing.

I had found these yesterday...

Amazon.com: Grounding Plug,Shielded Ethernet Patch Panel Bond Ground Extension Cord, for NEMA 5-15P 3 Prong Plug 20A Socket, 14 AWG,Ground Cable : Tools & Home Improvement

Amazon.com: Grounding Plug,Shielded Ethernet Patch Panel Bond Ground Extension Cord, for NEMA 5-15P 3 Prong Plug 20A Socket, 14 AWG,Ground Cable : Tools & Home Improvement

www.amazon.com

First I would install a ground block on the coax before the modem and connect the ground block to the third prong of an AC plug into the nearest outlet.

That was my conclusion as a first line of defense. So the above mentioned cable and a grounding block is where we'll start.

 

[KevinC]

I'm in possession of the device now, it has several crispy critter components just past the barrel connector jack for power. Nothing around the F-connector, but I know that doesn't really mean much as it could have entered there and tried to exit out the power jack.

 

[bharvey2]

I'm in possession of the device now, it has several crispy critter components just past the barrel connector jack for power. Nothing around the F-connector, but I know that doesn't really mean much as it could have entered there and tried to exit out the power jack.

Did you/your daughter get the grounding block and cable installed? Also, did your daughter or any of her neighbors find any other casualties other than her cable modem? Hopefully not but if you started see a pattern in damaged equipment (like other modems), it might be enough to motivate the cable co. to address the apartment's deficiencies if any exist.

 

[KevinC]

Did you/your daughter get the grounding block and cable installed? Also, did your daughter or any of her neighbors find any other casualties other than her cable modem? Hopefully not but if you started see a pattern in damaged equipment (like other modems), it might be enough to motivate the cable co. to address the apartment's deficiencies if any exist.

She hasn't bought a new modem/router yet, so nothing to attach the grounding block to. Everything else in her place survived. She keeps to herself so I doubt we'll ever know if anyone else had any damage or not.

I don't think the cable company will care, They stop at the demarc, everything past that is up to the apartment complex.

 

[freddaniel]

Call the cable company as they usually repair the system for free.

 

[buddrousa]

Only if you pay for inside wiring that they charge extra for each month.

 

[freddaniel]

It depends, many apartment/condo complexes contract for basic cable service included in the rent/fees. The cable company has an obligation to verify service is actually provided to each unit, even if it stops at the cable closet, down the hall from the unit. Generally, they will troubleshoot to the satisfaction of the owner, but may not fix the problem without extra payment. If the Daughter has TV and not modem, someone should simply test the cable outlet at the modem with a TV to verify signal level. It could be the modem is bad.

 

[dickie757]

My year long adventure with a R56 cert says dont do anything with a grounding system inside her apartment.

What would happen if the complex does not have a properly grounded entrance into the building? Or, what if it does?

If it does not, her place is now the demarc for EMP to traverse.

If yes, what will the extra grounding apparatus do to the coax system?

 

[Echo4Thirty]

She hasn't bought a new modem/router yet, so nothing to attach the grounding block to. Everything else in her place survived. She keeps to herself so I doubt we'll ever know if anyone else had any damage or not.

I don't think the cable company will care, They stop at the demarc, everything past that is up to the apartment complex.

Have you considered hiring a Motorola ST to bring it up to R56 standards?

Seriously though, i have seen enough CableCO installs to tell you that they dont care about NEC or anything other than pop a hole and run cable to a plate. I think your 75 ohm one would work as it goes DC to 3GHz, but where to find an appropriate grounding point near the wall plate would be what i would wonder. I mean there is one in the AC outlet, but I dont think the apartment folks would be thrilled about a ground wire running from your arrester to the 117 VAC wallplate's bare copper ground.

In my own house, their line comes from the pole, down my exterior wall to a nice super cheap 4 position splitter and then 4 wires to each room where they just drilled a hole, half ass sealed it and plugged it into a double female F wall plate. The splitter has the tiniest of wires going down to their own ground rod, not bonded to anything else.

 

[speedway_navigator]

My splitter is attached to my electrical ground.