Fire Alarm System Installation - Conduits

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Cluz

Member
I'm in a bit of a predicament right now with a project I'm developing. I'm planning to install a new fire alarm system in an industrial facility (Let's say ~1 million square feet for the sake of argument). The quotes that I've been receiving for the electrical installation have been very high and I'm trying to find a way to complete the project without breaking the bank.

Our spec calls for galvanized rigid conduit everywhere in the facility as we do wash-downs and conduit is often exposed to leaks and other less-than-ideal environments. My question is this - In your experience, what would be the cheapest and most effective way to complete the installation using a different type of conduit? We've been looking at flexible metal conduit, or some type of armored cable. Any help is appreciated.
 
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nhfire77

Senior Member
Location
NH
I agree with buck Parrish, properly installed EMT with properly tightened compression connector is more than enough unless it will be exposed to serious physical damage. I say properly, because if in ain't tight, it ain't right.

Rigid at the ceiling would be wicked overkill in most situations, unless you have a specific envriomental need, like a trash or recycling facility with stuff flying around.

Oh and weep holes at the low points, if applicable.
 
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jwjrw

jwjrw

Senior Member
nhfire77 said:
I agree with buck Parrish, properly installed EMT with properly tightened compression connector is more than enough unless it will be exposed to serious physical damage. I say properly, because if in ain't tight, it ain't right.

Rigid at the ceiling would be wicked overkill in most situations, unless you have a specific envriomental need, like a trash or recycling facility with stuff flying around.

Oh and weep holes at the low points, if applicable.
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I agree also. Ive seen a few projects here designed to be done in rigid then refigured so they could be done in emt.
 
growler

growler

Senior Member
Location
Atlanta,GA
Cluz said:
In your experience, what would be the cheapest and most effective way to complete the installation using a different type of conduit? We've been looking at flexible metal conduit, or some type of armored cable. Any help is appreciated.
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Your profile says that you are and Engineer in the food industry. The only reason I mention this is that there may be more than just electrical concerns in some areas.

The regulations on what can be used in food processing areas will be more strict than say out in a warehouse area. On the jobs that I have worked in the past there are normally different types of conduit used depending on what would be required for each area where it is installed. You may end up useing everything from stainless steel in some areas to flex being fished in existing walls in other areas all on the same job.

Most end up useing whatever is cheapest and will meet aproval for all codes and regulations concerned in the area of use.
 
gadfly56

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
You might try some LFMC-VF "Liquid-Tuff" from Kaf-Tech with suitable liquid-tight enclosures and fittings.

When you say "wash down" do you mean that fire alarm devices might be accidently hit with overspray or that they'll get a full-on dousing? You can get 3R-rated enclosure for pull stations from STI, but smoke detectors and heat detectors would be tough. You could also use outdoor-rated notification appliances, but I don't know how well they'd do under a direct stream.
 
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satcom

Senior Member
growler said:
Your profile says that you are and Engineer in the food industry. The only reason I mention this is that there may be more than just electrical concerns in some areas.

The regulations on what can be used in food processing areas will be more strict than say out in a warehouse area. On the jobs that I have worked in the past there are normally different types of conduit used depending on what would be required for each area where it is installed. You may end up useing everything from stainless steel in some areas to flex being fished in existing walls in other areas all on the same job.

Most end up useing whatever is cheapest and will meet aproval for all codes and regulations concerned in the area of use.
Click to expand...

We were just talking with a contractor working on a new food processing plant, he said they had plastic coated rigid conduit in the processing areas, and rigid conduit in all the other areas, they were doing both electrical and fire systems.
 
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Cluz

Member
Thanks for the replies! I should have mentioned this earlier, but we don't want to use EMT. It was tried many times previously in our facility and has failed us many times. It truly is a rough environment that I'm working with here.

Gadfly, although it's not the same in every area, we wet wash the floors and walls with water. Naturally people can be careless and blast the ceilings and surrounding conduit as well.

The standard throughout our facility is at least a NEMA 12 enclosure. As fire alarm systems aren't created with a NEMA rating, we're planning to use all weather-proof pull stations etc.
 
cadpoint

cadpoint

Senior Member
Location
Durham, NC
horsegoer said:
Is it true that some compression fittings are not water tight rated and some are?
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Yes,
The last exposed emt ones I used had a green throat bushen liner and a rubber washer on the coupling and a slight green body on the compression connector.

I don't want to say what they are described or used for, ... it's in the good book!

I don't want to say the wrong thing with the code and word smith here. :)
 
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