Detailed Conduit Routing?

[shamsdebout]

I wanted some advice as I am fairly new in the industry as an electrical designer, I am finding that I am being asked by the architects how conduits will be routed in the building and I don't really know as much detail about that. Could someone with more experience help me out. If someone can: cover the basic methodology of conduit routing, (typically how do you route conduit for floor boxes, etc). A quick or extensive run-down would be appreciated.

 

[bsh]

Generally, routing conduit on drawings is a waste of time. They usually get installed differently than drawn. Since most conduit is fairly small (compared to 6"+ mechanical pipe) they can be installed fairly easily. There are some areas that need to be looked at carfully though.
1. When you have many conduits running together make sure there is sufficient space for the conduit.
2. Pay attention to bending radius.
3. When conduit goes through a wall or floor it can affect the structure so pay attention to those areas also.
4. Pay attention to conduit in a floor slab. Conduit crossing in a floor slab can cause a structural problem and the route may need to be noted on the drawings.
These are just a few things to consider. If possible, find an electrician and ask some questions about installation practices

 

[peter]

There are about as many ways to run conduit as there are electricians.
For instance, a common way to supply receptacles is to run your conduit on top of the wall with a drop down box at each location. A varient is to do that except the last two in the run: One goes down as usual and the last one also comes out of the box and goes over and then down to the last receptacle. Or you could just drop down to the first outlet and then tie the rest of the outlets together which will save boxes and maybe so conduit.
So, you see, there are numerous ways of running even something simple.
Estimators make the mistake of just counting the distance between receptacles with the result of not ordering enough conduit, fittings and boxes. This holds up the entire job and the labor budget gets biloxied.
~Peter

 

[Buck Parrish]

I wanted some advice as I am fairly new in the industry as an electrical designer, I am finding that I am being asked by the architects how conduits will be routed in the building and I don't really know as much detail about that. Could someone with more experience help me out. If someone can: cover the basic methodology of conduit routing, (typically how do you route conduit for floor boxes, etc). A quick or extensive run-down would be appreciated.

You should draw out the location of the big conduits. Feeders and telephones are some times two 4".
Avoid the duct work!!
Floor boxes will obviously be in the slab. Maybe fire , too.
Other then that on the drawingw. You place a little arrow pointing to the home run. The electrician will take it from there.

 

[e57]

Two rules:

• Big holes - small holes
• Big pipe - small pipe

Then on your line diagram create different line styles for where they will be.... Since these are often only representational - you should add a not about positioning to be exact or withing scaled or dimensioned tolerances.

And by all means - do this before some poor sucker bids the job....

Not sure - but as an "electrical designer" should you already know this?

 

[e57]

I should also add that in doing so you'll be taking on both a design role for any exposed conduit, and an engineering role in any sizes, lengths or circuitry you provide....

 

[jeremysterling]

There are about as many ways to run conduit as there are electricians.

True that

This holds up the entire job and the labor budget gets biloxied.

biloxied!?

 

[MNWildcat]

What is the context of the request? Specific to an area of the project, expose conduit, all the conduit???

IMO, the architect is requesting this for one of two reasons.
1. They are trying/wanting you to note something that is out of your control. As said above, routing is by the ECs. You show it one way, it will be installed another*.
2. They are not very experienced and see the ME plans with duct/pipe routing and expect the same level for conduit. Again as said above, there is a big difference between ME plans and EE plans.

* Though if you have a lot of large conduits and in either a certain architectural looking area or in an existing or future area that will be packed, some design coordination go a long way in working out those issues ahead of time. I have indicated certain sets of large conduit on the plans for specific areas.

Small stuff you should not show. If you show it one way, it may cost you more as one EC can do it easier/cheaper a different way.

 

[jeremysterling]

The HVAC duct work has been mentioned already. Find someone familiar with MEP (Mechanical, Electrical, Plumbing) coordination. Check your specs: don't spec out MC and not have a drop ceiling (sorry folks, I've exploited that one before).

Floor boxes: Before the deck pour, I run 3/4 smurf or PVC from the 68P (T&B) to a RMC or PVC 90? that stubs up where the nearest stud wall is indicated on the plans. After the pour, the framers notch their track over my stub-up.

Ceiling Boxes: Before the deck pour, I run 3/4 smurf or PVC from the concrete 4/O box (nailed to the deck) to a "red dot 90?" over the switch location in the stud wall.

 

[ohmhead]

Well we take the electrical prints and spend months locating every feeder conduit an system conduit per the risers .We locate every elect room and every data com room then we find the best route .

Heres how we look at mechanical -plumbing - structual -architectural-civil-to locate a path that is able to handle our electrical duct banks or branch raceways needed per electrical drawnings.

Other trades have it done for them we move for others on every job .

What makes me laugh is the plumbing is shown in place per drawnings .

The mechcanical is shown in place per drawnings.

The building is per arch- struc drawnings .

The civil site sewer santiary piping is per elevation and cor-location .


But the electrician has to locate his conduits around all other trades and then cad the routing of these conduits and overlay these and work out the problems before we start work this takes months of coordination at meetings with other trades and i have never seen a electrical engineer or a mechanical engineer sit down and say what about the electrical can we look at how to route it ?

Its lots of fun laying out a electrical project what id like to see is one job that gives the electrician a good sized electrical rooms a path for our conduits just for us only and that means risers and duct banks .

Tell them to talk to me .

 

[Karl H]

I can see doing a duct or E-pipe detail for an industrial plant ie. refinery,
power plant. But a detail pipe run for a standard building is a serious waste of
your time, well unless it's all slab work. The electricians are the ones that will
decide the TRUE route based on the real-life obstacles the building and other
trades present. I have tried this a few times only to find the electricians
had a very valid reason for not following my predetermined route.
On almost every occasion it was another trade taking up the space I routed
because "They" didn't follow their predetermined route.

 

[JFletcher]

Good points, all.

"If someone can: cover the basic methodology of conduit routing.."

Basically, I'm going to route the conduit for the shortest possible runs, with a minimum number of sweeps and sized appropriately for the cable, all the while hoping I'm not going to run into too much lvl, steel beams, inaccesible ceilings or mechanical systems (plumbing, sprinklers, hvac, etc.). I've worked a few buildings where this was architecturally impossible, mainly due to undrillable beams and finished ceiling height clearances.

 

[Rockyd]

Click here for some ideas to help you along. Besides "The Forum" Mike Holt carrys some great books and DVD's covering various portions of the industry.

 

[hillbilly]

True that



biloxied!?

Me too.

First time I've heard that

I'll have to try it out.

steve

ps, I've been to Biloxi (Mississippi) many times, and been "biloxied" a few times in their casinos.

 

[rr]

I wanted some advice as I am fairly new in the industry as an electrical designer, I am finding that I am being asked by the architects how conduits will be routed in the building and I don't really know as much detail about that. Could someone with more experience help me out. If someone can: cover the basic methodology of conduit routing, (typically how do you route conduit for floor boxes, etc). A quick or extensive run-down would be appreciated.

Unless the conduit is exposed or is be installed in a tight space, it really doesn't matter how the conduit is routed. The EC will determine the most efficient way possible. Explain to the architect that conduit routing indicated on Construction Documents is diagrammatic only.

A typical floor box could be routed in several ways. Trenched with conduit routed to the nearest wall, poke-thru's with conduit routed on floors below, or channel-type duct systems.

Good Luck!

 

[PCN]

I wanted some advice as I am fairly new in the industry as an electrical designer, I am finding that I am being asked by the architects how conduits will be routed in the building and I don't really know as much detail about that. Could someone with more experience help me out. If someone can: cover the basic methodology of conduit routing, (typically how do you route conduit for floor boxes, etc). A quick or extensive run-down would be appreciated.

We typically show underslab conduit routing and stub up location so we have good idea what's where for future slab cuts. And in the more congested areas with large conduits we will suggest general routing areas to avoid conflicts with other trades.

Depending on the architecture of the building, routing might be critical to conceal as much as possible. As noted there are many methods to get from point A to point B.
I don't think there is an easy answer to your question, it's usually best to let the EC run it as they see fit.

The most frustating thing is we always want our panel feeders run over head due to easier remodeling in the future. We note this on the plans and 80% of the time it ends up underslab anyway. My point is don't kill youself trying to lay this out how you think is best, it most likley wont end up per plan anyway.

 

[PCN]

Two rules:

• 
  
  
  Not sure - but as an "electrical designer" should you already know this?

• 
  
  My boss is an electrical engineer, mechanical engineer and a registered architect and a PE. Generally speaking he knows more about everything and anything than I will ever know.
  But ask him to layout a conduit run logically, economically like an EC would and he would struggle. Not everybody has laid pipe. If you know what I mean.

 

[jdsmith]

I can see doing a duct or E-pipe detail for an industrial plant ie. refinery,
power plant. But a detail pipe run for a standard building is a serious waste of
your time, well unless it's all slab work. The electricians are the ones that will
decide the TRUE route based on the real-life obstacles the building and other
trades present....

Even in a refinery we try not to get too excited about exact routing. Stub ups are detailed because they do matter and section views of duct banks are provided due to heat loss calculations. All other cable tray and conduits are shown diagramatically because the electricians will figure out the most efficient way to do their work. Anything else will cost more in engineering time than it is worth and it will be ignored anyway because electricians know how to run conduit better than engineers. If a particular offset, elevation, bend, etc. is important we try to put a note on the prints indicating the issue we're designing around so that particular detail doesn't get changed in the field.

 

[shamsdebout]

I want to thank all for your response, I am now more aware of how everything works and I will notify the architect that the EC will handle the detailed conduit routing.

 

[petersonra]

I used to work for a place that did design/build/install projects. The only time we ever showed where conduits were actually routed was when it was required so the PE doing the seismic calcs could do his thing.