Seperate Conduit Systems

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vidividi12

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It is mentioned in our project specifications that it shall be provided that each electrical system, including, but not limited to, power feeders, motor branch circuits, lighting, appliance and receptacle power, emergency lighting, telecommunication and data and fire alarm system in seperate conduits.

However, as far as I know there should be no restriction items in NEC to install power, receptacle power and lighting feeders in same conduit systems. What might have been explained in this specification with this item?
 
Generally emergency and "normal" system are required to be kept separate. Lighting, power, feeders, etc can all occupy the same raceway system. Mixing feeders and branch circuits is generally not a great design because the increase in the number of CCC's in a raceway will require derating and will usually make the larger feeder conductors need to be increased in size which can increase costs.
 
vidividi12 said:
as far as I know there should be no restriction items in NEC to install power, receptacle power and lighting feeders in same conduit systems.
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NEC Code defines a national guideline to follow but a job specification can go over and beyond a code requirement requesting more than what is legally required. stating for example all conductors need to be gold plated.
 
I think architects/engineers have access to secret reserves of boilerplate that they throw around to appear more knowledgable.
Such as "stranded wire only," "solid wire only," "compression connectors only," "no 1/2 inch. EMT" etc.
I have never seen the one you mention. In my experience, if they came up with something impractical or illogical, the
good ones could be convinced to cross it out if you gave them a reason.
 
vidividi12 said:
It is mentioned in our project specifications that it shall be provided that each electrical system, including, but not limited to, power feeders, motor branch circuits, lighting, appliance and receptacle power, emergency lighting, telecommunication and data and fire alarm system in seperate conduits.

However, as far as I know there should be no restriction items in NEC to install power, receptacle power and lighting feeders in same conduit systems. What might have been explained in this specification with this item?
Click to expand...

There could be any number of valid reasons to separate systems that have nothing to do with the NEC or with safety per se. Some more or less random possibilities I can think of:
  • ensuring that a problem or required work on one system does not effect others
  • making the installation more flexible for modification or expansion
  • generally keeping a site organized and documented to allow for good maintenance
  • reducing or controlling for electromagnetic interference between systems (might be important in a scientific facility with sensitive instruments)
It's a job spec, whether it is reasonable depends on the purpose of the facility and the systems.
 
What is the project?
Government?
Federal, State,?
Industrial?
I've done many jobs with specs. on every facet of ID, labels, painting color codes, size, etc..
 
In as few words as possible, the specification writer is trying to contractually establish an equal footing for all bidders to do probably what most reasonable bidders would do anyway. Sometimes it gets a little carried away. For example, most would never mix power feeders, non-emergency branch circuits of any type, emergency lighting, telecommunications, data and fire alarm system circuits in the same conduit. So they state that and it freaks people out, but you wouldn't do it anyway due to cable voltage differences, Article 700 limitations, signal crosstalk, or simple ccc derating avoidance.
 
ron said:
In as few words as possible, the specification writer is trying to contractually establish an equal footing for all bidders to do probably what most reasonable bidders would do anyway. Sometimes it gets a little carried away. For example, most would never mix power feeders, non-emergency branch circuits of any type, emergency lighting, telecommunications, data and fire alarm system circuits in the same conduit. So they state that and it freaks people out, but you wouldn't do it anyway due to cable voltage differences, Article 700 limitations, signal crosstalk, or simple ccc derating avoidance.
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to a certain extent yes. Your service conductors or feeder to a separate building still carries all the load types being supplied, maybe even a feeder to a remote area or an addition to an existing building.
 
Does emergency branch circuits require fire protection?
 
vidividi12 said:
It is mentioned in our project specifications that it shall be provided that each electrical system, including, but not limited to, power feeders, motor branch circuits, lighting, appliance and receptacle power, emergency lighting, telecommunication and data and fire alarm system in seperate conduits.

However, as far as I know there should be no restriction items in NEC to install power, receptacle power and lighting feeders in same conduit systems. What might have been explained in this specification with this item?
Click to expand...
People write specs all the time that require things that are not in the code. They want it done that way so they put it in the contract so you do it that way. Sometimes they want the conduits painted a particular color. Not code but it's required if it's in the contract.

Some people don't like PVC conduit so despite it being allowed in many cases, they will put a requirement in the spec that says you can't use it.
 
infinity said:
What do you mean by fire protection? Typically we run EM circuits in MC cable or EMT.
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I am referring to 700.10(D)(1) & 700.10(D)(2), it doesn't show exact requirements of fire protection for branch circuits,

Do MC cable or EMT listed for fire protection?
 
petersonra said:
People write specs all the time that require things that are not in the code. They want it done that way so they put it in the contract so you do it that way. Sometimes they want the conduits painted a particular color. Not code but it's required if it's in the contract.

Some people don't like PVC conduit so despite it being allowed in many cases, they will put a requirement in the spec that says you can't use it.
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Peter,
This thread since April.
 
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