radio tower affecting FIRE ALARM SYSTEM

[jflynn]

Hello-we are working on a rather large project in mass, the building has had multiple phases of turnover as the project has progressed.4-towers and a garage.
we are currently on the last 2-turns for the project,we have been struggiling getting the last 2-parts of the project on line with our fire alarm system.
after days/weeks of troubleshooting it was noted that the radio tower that is closest to the end of the building we are trying to finsih is affect our SLC loop ,to the point of where the system will not map any devices on that end of the building-we could actually here the radio station thru a simple toner when we placed it next to the wiring for the SLC Loop.
we have tried some filters along with the manufacturer,did not solve the issue,we did not use shielded cable because it was not called out to be used with the system-the FACP is located in the garage on the proiject which i am being told is acting as an insulator from the first and second tower currently on line and that is why we were able to get the first to turn on the system with limited issues-now that we are on the closest end to the towers we can not get the system to map.
i can tell you this is a large apartment complex with 2x4 wood construction and we used FPLP cable for the system.
does anyone have any ideas/soluitonds to try?-we are at a loss and have never dealt with this conditon before now.
thank you...

 

[ramsy]

..we did not use shielded cable because it was not called out..

See what happens with shielded cable ran along the floor to some device(s), from FACP to the worst end of the building.

 

[gadfly56]

Assuming that ramsy's suggestion yields a glimmer of hope, the only solution I see is to re-run the SLC in shielded cable. Or, you might put in a data gathering panel (DGP) at that end of the building and only re-run those portions where the radio tower effect exists. Whatever, it's not likely to be cheap. I hope your contract has a clause excluding "unforeseen/unforeseeable conditions".

 

[steve66]

If all else fails, you might consider if you can put non-addressable devices on that end of the building.

 

[K8MHZ]

I would try a few turns of cable through a snap on ferrite choke first. Like one of these:

 

[gadfly56]

I would try a few turns of cable through a snap on ferrite choke first. Like one of these:

Not likely to help. The RF from the towers is swamping the digital signal on the SLC; the S/N ratio is just too low. The SLC conductors are acting like a free air antenna.

 

[junkhound]

Conduit and compression fittings.

 

[topgone]

Conduit and compression fittings.

I once had a problem once with TF wires and solved it by conduiting (RMC).

 

[RLyons]

I cannot begin to tell you the man hours wasted trying to figure out why the fire alarm on a job sight I was on was always going into trouble. I't was just by coincidence I was tracing a missing 120v feed wire that I noticed country music play through my toner.

I was using all notifier panels and all my issues were related to the nac,not the slc. I tried ferrite chokes and they seemed to decreased the amount of troubles but for all I know troubles were dependent on the weather.

The fix? Changed all the nac booster panels from notifier to potter and haven't had an issue since.

Good luck

 

[gadfly56]

I once had a problem once with TF wires and solved it by conduiting (RMC).

Effective, but with the cable already installed and possibly behind drywall, not the solution your bottom line wants to hear.

 

[steve66]

I had some second thoughts about this, and are you 100% its the radio that is the problem? Have you checked everything else?

Is everything is wired correctly? Could there be a bad device or connection on the last loop that is killing the network communication? Are all the cables terminated properly, and is the EOL connected?

I'm not surprised you hear a radio station on the tone locator, but it has an amplifier in it, so it will amplify any small signal it receives. It might even be picking up the radio station on the short 3 or 4" leads attached to the toner.

 

[ActionDave]

Conduit and compression fittings.

Conduit yes. Compression fittings got nothing to add.

I got to run a bunch of 3/4 emt and pull a new cat 5 at hospital because the naked cat 5 was triggering a code pink. Code pink means there is newborn baby being abducted and the whole hospital goes into lockdown.

We used set screw fittings and everything worked out fine.

 

[gadfly56]

Conduit yes. Compression fittings got nothing to add.

I got to run a bunch of 3/4 emt and pull a new cat 5 at hospital because the naked cat 5 was triggering a code pink. Code pink means there is newborn baby being abducted and the whole hospital goes into lockdown.

We used set screw fittings and everything worked out fine.

I don't like compression fittings. They always seem to find a way to loosen up, and if there's enough slack in the run the EMT separates. I've always used screw fittings and tighten down until I put a dimple in the tube.