ckt qty in emt

[Alwayslearningelec]

if you had to run emt for receptacles and had some along a common wall that were feed from multiple 1p-20a circuits how many circuit would you combine in a 3/4” pipe with #12 thhn before dropping a another separate pipe? some things that come to mind to consider :

1. box fill
2. separate neutrals needed
3. separate grounding conductors needed
4. derating .

for some reason i think i remember someone telling me they wouldn’t pull more than 3 ckts between receptacles in a common pipe.

 

[LarryFine]

The magic number for maximum CCCs without derating/upsizing is 9.

With no shared neutrals, that's four circuits.

 

[augie47]

agree with Larry
even then you need to watch your box fill

 

[ActionDave]

if you had to run emt for receptacles and had some along a common wall that were feed from multiple 1p-20a circuits how many circuit would you combine in a 3/4” pipe with #12 thhn before dropping a another separate pipe?

With separate neutrals, derating, and pipe fill there is no reason to use 3/4 EMT unless you just like wasting money.

for some reason i think i remember someone telling me they wouldn’t pull more than 3 ckts between receptacles in a common pipe.

The only reason I can think of to pull three circuits is to leave room in case you need to come back and add a circuit.

 

[Alwayslearningelec]

With separate neutrals, derating, and pipe fill there is no reason to use 3/4 EMT unless you just like wasting money.

The only reason I can think of to pull three circuits is to leave room in case you need to come back and add a circuit.

spec doesn’t allow 1/2”

 

[Alwayslearningelec]

The magic number for maximum CCCs without derating/upsizing is 9.

With no shared neutrals, that's four circuits.

you’d pull 4 ckts on one pipe between receptacles dropping off ckts at receptacles as needed??

 

[augie47]

you’d pull 4 ckts on one pipe between receptacles dropping off ckts at receptacles as needed??

 

[infinity]

you’d pull 4 ckts on one pipe between receptacles dropping off ckts at receptacles as needed??

What you're proposing will work just fine providing the boxes are sized properly. Derating and conduit fill are not an issue.

 

[James L]

you’d pull 4 ckts on one pipe between receptacles dropping off ckts at receptacles as needed??

For me, part of it would depend on my wire rack(s). Do you have enough space on one rack for all of those extra spools of white and green? Is a big hassle to use 2 racks?

 

[Alwayslearningelec]

What you're proposing will work just fine providing the boxes are sized properly. Derating and conduit fill are not an issue.

Thanks. How about the practicality of actually pulling these wires/doing the installation? Not unrealistic to pull 4 ckts(8 CCC) through to several different receptacles along common wall?

Maybe just dropping TWO separate pipe from the ceiling down each with two circuits might be easier. Guess I'm just splitting hairs now.

 

[Alwayslearningelec]

For me, part of it would depend on my wire rack(s). Do you have enough space on one rack for all of those extra spools of white and green? Is a big hassle to use 2 racks?

Interesting point and part of what I was asking about the practicality of doing the install.

 

[rambojoe]

spec doesn’t allow 1/2”

And is a waste of money..slow to get the fish in anymore than 2 bends and sucks to pull. In fact if i could push a button to get rid of 1/2", there would be a ka-boom. An earth shattering ka-boom
But yes, i know, it has its place in situations, just not on homers, at least

 

[infinity]

Thanks. How about the practicality of actually pulling these wires/doing the installation? Not unrealistic to pull 4 ckts(8 CCC) through to several different receptacles along common wall?

Pulling the wire isn't an issue if you're using stranded conductors.

 

[Alwayslearningelec]

Pulling the wire isn't an issue if you're using stranded conductors.

What does stranded have to do with it? Assume much easier to work with/pull than solid?

 

[Rick 0920]

if you had to run emt for receptacles and had some along a common wall that were feed from multiple 1p-20a circuits how many circuit would you combine in a 3/4” pipe with #12 thhn before dropping a another separate pipe? some things that come to mind to consider :

1. box fill
2. separate neutrals needed
3. separate grounding conductors needed
4. derating .

for some reason i think i remember someone telling me they wouldn’t pull more than 3 ckts between receptacles in a common pipe.

Also consider ambient temperature. If the derated ampacity falls below 20 amps and the circuit has more than 1 receptacle, a 20 amp breaker would be a code violation.

 

[LarryFine]

you’d pull 4 ckts on one pipe between receptacles dropping off ckts at receptacles as needed??

That seems to be your goal.

 

[LarryFine]

Thanks. How about the practicality of actually pulling these wires/doing the installation? Not unrealistic to pull 4 ckts(8 CCC) through to several different receptacles along common wall?

Not difficult at all, but I'd use a different color for each circuit's line conductor.

 

[LarryFine]

Also consider ambient temperature. If the derated ampacity falls below 20 amps and the circuit has more than 1 receptacle, a 20 amp breaker would be a code violation.

That's where the magic number 9 comes in.

 

[infinity]

What does stranded have to do with it? Assume much easier to work with/pull than solid?

It wouldn't be an issue to do it the way you've proposed. Stranded wire makes looping in and out of boxes much easier.

 

[petersonra]

spec doesn’t allow 1/2”

This is a common requirement in specs. I'm not sure what the thinking is but if you read the spec carefully it may actually say minimum size of conduit is half inch. EMT is not conduit.