Cables sharing a conduit

[Zeh]

Can a run of coax and a rotator control cable be buried in the same conduit? Wouldn't the cable powering the rotator introduce noise? I'm reading around and thinking about how I would install my W6LVP loop in the backyard away from buildings!

 

[a417]

Can a run of coax and a rotator control cable be buried in the same conduit? Wouldn't the cable powering the rotator introduce noise? I'm reading around and thinking about how I would install my W6LVP loop in the backyard away from buildings!

Would the cable powering the rotator be energized all the time, or only when the device was moving the antenna? If it's good shielded coax, terminated and grounded appropriately, I wouldn't worry.

 

[ArloG]

Well of course the rotator cable should have a braided or wrapped shield.
If the rotator motor is brushed you could probably expect a little noise.

 

[Zeh]

Would the cable powering the rotator be energized all the time, or only when the device was moving the antenna? If it's good shielded coax, terminated and grounded appropriately, I wouldn't worry.

Thanks for the response! I would only have it powered on to rotate the antenna and then turn off the control box. The coax will probably be RG-6.

 

[Zeh]

Well of course the rotator cable should have a braided or wrapped shield.
If the rotator motor is brushed you could probably expect a little noise.

Thanks for the response, I was thinking about getting the cable in the amazon bundle for the RCA VH226E rotator:

100' FT Antenna Rotor Cable

Unless there is a better recommended cable. Also, does the control cable need its own grounding/lightning arrestor?

 

[prcguy]

I've been a project manager on many commercial underground conduit/cable installs and have also done my share of the work. Typically you never run AC power and signal cables in the same conduit and there are different burial depth rules for signal and low voltage cables vs cables with over 30 volts.

You can run low voltage and signal (RF) cables in the same conduit unless the power cables will somehow cause interference to the signal cables. In this case there is a chance when the rotor is turning there could be interference to the signal cables from voltage spikes. Its up to the owner in this case to decide if he can live with the occasional interference or if a separate conduit is warranted.

 

[ArloG]

Thanks for the response, I was thinking about getting the cable in the amazon bundle for the RCA VH226E rotator:

100' FT Antenna Rotor Cable

Unless there is a better recommended cable. Also, does the control cable need its own grounding/lightning arrestor?

https://www.amazon.com/Belden-Brilliance-Instrument-Beldfoil-Shield/dp/B00CWENGV2/ref=sr_1_2?crid=3ESZLDWVQYLQW&keywords=3+conductor+shielded&qid=1660246526&s=electronics&sprefix=3+conductor+shielded%2Celectronics%2C80&sr=1-2

 

[fourgres]

In the event of a lighting strike by either the rotor cable or RG6 cable one might damage the other, best kept seperate, As a retired utility worker we NEVER put different voltage cables in the same conduit. ie 120v cable with phone cables, relay cables with AC voltage. But again what is the chances of a lighting strike. lol

 

[Zeh]

I've been a project manager on many commercial underground conduit/cable installs and have also done my share of the work. Typically you never run AC power and signal cables in the same conduit and there are different burial depth rules for signal and low voltage cables vs cables with over 30 volts.

You can run low voltage and signal (RF) cables in the same conduit unless the power cables will somehow cause interference to the signal cables. In this case there is a chance when the rotor is turning there could be interference to the signal cables from voltage spikes. Its up to the owner in this case to decide if he can live with the occasional interference or if a separate conduit is warranted.

Yeah, that would be a problem if I'm trying to hear changes in signal quality while making adjustments. After reading these responses, it's looking like they should be separate.

 

[Zeh]

In the event of a lighting strike by either the rotor cable or RG6 cable one might damage the other, best kept seperate, As a retired utility worker we NEVER put different voltage cables in the same conduit. ie 120v cable with phone cables, relay cables with AC voltage. But again what is the chances of a lighting strike. lol

Ok then, it looks like I'll be using two conduits. Does the control cable need to be grounded to the utility ground like the coax run?

 

[prcguy]

Per NEC I would say yes. Do a search on "NEC article 810" and you will get lots of info on antenna system specific grounding.

Ok then, it looks like I'll be using two conduits. Does the control cable need to be grounded to the utility ground like the coax run?

 

[ArloG]

I guess then CCTV installs and satellite dishes with an actuator to move them are screwed.
Because they use Siamese cable with coax and power integrated in the jacket. In the case of satellite installs there are even sense wires for positional encoders. I do agree separate cables are the best idea. All 4 cables here. 2 coax, shielded motor power, and shielded encoder cable, run in one conduit. Installed and operational since the mid 80's.
Considering video signals are actually RF in the, oh let's throw 7...14 MHz in there for giggles.
And composite video is always sent over coax. With better quality cable for commercial installs being embossed with the UL and CSA logos.
But yeah. We're not looking at usually anything over 36 VDC for even the most robust dish actuators.
If lightning is going to hit. It's going to hit. Pure and simple.

 

[Zeh]

Per NEC I would say yes. Do a search on "NEC article 810" and you will get lots of info on antenna system specific grounding.

Yeah, I suspected as much... Looks like this project is going to be bigger than anticipated. Thank you for the reference!

 

[Zeh]

I guess then CCTV installs and satellite dishes with an actuator to move them are screwed.
Because they use Siamese cable with coax and power integrated in the jacket. In the case of satellite installs there are even sense wires for positional encoders. I do agree separate cables are the best idea. All 4 cables here. 2 coax, shielded motor power, and shielded encoder cable, run in one conduit. Installed and operational since the mid 80's.
Considering video signals are actually RF in the, oh let's throw 7...14 MHz in there for giggles.
And composite video is always sent over coax. With better quality cable for commercial installs being embossed with the UL and CSA logos.
But yeah. We're not looking at usually anything over 36 VDC for even the most robust dish actuators.
If lightning is going to hit. It's going to hit. Pure and simple.

Here in SE Texas, we get wicked lighting storms on occasion so lightning protection is a must. Well, 'best we can do' lightning protection because you're right, there's nothing that can done about a strike. Guess I should gloss over the insurance policy too...