Running multiple 240v in the same conduit

[Marine77]

I am in the process of converting my 40x70 pole barn into a workshop. It only has electrical on one side and I was looking to add 240v 30amp for my planner, jointer, table saw, shaper and dust collection ( 5 in total) looking to save money I agreed I would pull the line and install the conduit and the electrician would do the rest.

I have a surplus of 1" EMT and will have no issues with the conduit but was looking to confirm a few things as I have limited knowledge with running lines.

1) Can I run all 5 circuits in the same conduit? Was going to use 10/2 THHN
2) Based on what I've read, I should run a separate ground for each circuit.
3) And lastly, if I wanted to pull a 110v 12/2 with the other wires could I do that in the sane conduit too?

Thank you for reading and I appreciate any feedback!

 

[sberry]

You would need 1 ground or none as the pipe may be used but there are some things to consider. How full the pipe is, how many current carrying conductors there are to some extent and the true size of the saws. Some may be able to share a circuit.

 

[wyliesdiesels]

I am in the process of converting my 40x70 pole barn into a workshop. It only has electrical on one side and I was looking to add 240v 30amp for my planner, jointer, table saw, shaper and dust collection ( 5 in total) looking to save money I agreed I would pull the line and install the conduit and the electrician would do the rest.

I have a surplus of 1" EMT and will have no issues with the conduit but was looking to confirm a few things as I have limited knowledge with running lines.

1) Can I run all 5 circuits in the same conduit? Was going to use 10/2 THHN
2) Based on what I've read, I should run a separate ground for each circuit.
3) And lastly, if I wanted to pull a 110v 12/2 with the other wires could I do that in the sane conduit too?

Thank you for reading and I appreciate any feedback!

The problem you will have is that 310.15(b)(3)(a) requires 10-20 CCC(current carrying conductors) in the same raceway to have their ampacity reduced by 50%. For #10 THWN this means 20a max OCPD.

The other issue is u may be over max conduit fill...Im too tired tonight to calculate...

 

[finn]

I'm no electrician, but in a one man shop, it's not possible to run a saw, planer, joiner, and shaper concurrently, is it?

Wouldn't more than two or three circuits be overkill?

The other possible solution would be a sub panel in the machine work area.

 

[Marine77]

Thank you for your responses. Reading more about putting a sub panel there might be a better option. I appreciate the adivice as I has a felling I would be redoing this if I didn't ask.

As to why the 5 circuits I may have misunderstood the electrician. I thought he said that with 240 I had to run a seperate circuit ( lines to each machine) and they could not be daisy chained like 120. To your point other than the dust colletion, no 2 machines would ever be running at the same time. Do I need to run 10/2 to each machine? Sorry for the elementary questions ��

 

[Cmreschke]

Ok so you need a minimum of 2 conduits if your pulling 5 240 volt ckts. 1 ground in each conduit if your not using conduit as ground.

As for your other question in regards to running multiple machines off of the same ckt. I don't believe it to be code compliant unless you were to add up all that you want to run size your wire accordingly then seperately fuse them at the machine to the lower size. Now I'm not saying you couldn't do what you wanted to assuming your the only one working. Worst case you trip a breaker from overload. If you asked me to do it I'd probably do it, I've done it in the past for a customer. Wasn't getting inspected. Is it gonna burn your barn down, very slim chance of that.

 

[Aceman]

If you're hiring an electrician, let him answer these questions for you. Although there is a National Electrical Code, not every area follows it or is on the same code cycle. There are local and state amendments as well more often than not. You're electrician should be well versed in what is required in your area, more so than the GJ members scattered all over the internet.

Since I do this for a living, I will also mention that I would not let a homeowner run the conduit and pull the wire so I could do the "hookup". Sorry. Most electricians aren't so hard up for work that they want to assume the liability for someone else who ran the conduit and pulled the wire.

That's not mentioning, permits. In Oregon, if we're doing the work, we're pulling the permit. Our name is on it as well as all the responsibility that comes along with it. If a homeowner pulls the permit, then they are responsible for doing the work themselves, we don't work under homeowner permits.

 

[Speedy Petey]

As to why the 5 circuits I may have misunderstood the electrician. I thought he said that with 240 I had to run a seperate circuit ( lines to each machine) and they could not be daisy chained like 120. To your point other than the dust colletion, no 2 machines would ever be running at the same time. Do I need to run 10/2 to each machine? Sorry for the elementary questions ��

If your "electrician" said this I'd find another one that knows what he is doing. THere is no such prohibition in the NEC, nor any local amendments I have ever heard of.

Also, there is no such thing as "10/2 THHN". THHN/THWN is individual conductors, not cable. So for a 240V circuit you would simply need two conductors, and one ground for the whole conduit, sized to the largest circuit within.

 

[Speedy Petey]

Since I do this for a living, I will also mention that I would not let a homeowner run the conduit and pull the wire so I could do the "hookup". Sorry. Most electricians aren't so hard up for work that they want to assume the liability for someone else who ran the conduit and pulled the wire.

That's not mentioning, permits. In Oregon, if we're doing the work, we're pulling the permit. Our name is on it as well as all the responsibility that comes along with it. If a homeowner pulls the permit, then they are responsible for doing the work themselves, we don't work under homeowner permits.

I fully agree with this, except the bold part. Around here any contractor worth hiring has more work available than he can handle. I get a few panic calls a week that someone's guy didn't show up, or never called back, and that everyone they call is swamped. I tell them I am in the same boat.

 

[md21722]

The electrician is probably saying that for simplicity and ease of passing an inspection. When wiring multiple motor circuits there are a number of requirements that must be met and its typically easier with smaller motors that are hardwired.

For example, 2 x 2 HP motors, NEC says wire size is to be 12A X 125% + 12A = 27A with maximum breaker 12A X 250% = 30A with all wiring up to thermal protection point being capable of 30A (#10). So if your cords are #14 or #12 you'd have to change them to #10.

If you decided instead to try and run 3 x 2 HP motors, you can't really do it. Wire size would be 12A X 125% + 12A + 12A = 39A with maximum breaker 12A X 250% = 30A again with #10 up to the thermal protection point.

This works best on smaller motors that are higher voltage and 3 phase where you can string a few motors using #12 or #14 wire...

As another poster suggested, a sub panel is probably your best bet. You do not need to size the sub panel for every machine running the same time. Load calculations can come into play and mutually exclusive loads will cancel each other out. You only need enough to power one machine and the vacuum system simultaneously.

 

[Speedy Petey]

The electrician is probably saying that for simplicity and ease of passing an inspection. When wiring multiple motor circuits there are a number of requirements that must be met and its typically easier with smaller motors that are hardwired.

For the purposes of inspection he is wiring receptacles, not motors. This is a dwelling setting, not a commercial shop.

 

[Justanoldguy]

Everything Electrical sounds so complicated in the USA.
Here in NZ everything is either single phase 240v or 3 phase 400v.

 

[md21722]

For the purposes of inspection he is wiring receptacles, not motors. This is a dwelling setting, not a commercial shop.

Valid point for non hard-wired equipment. I suggest the Op go with the sub panel to make everyone happy.

 

[Marine77]

Thank you for everyone's feedback. I will looking into having a sub panel installed. Sounds like it makes the most sense.

 

[bjcouche]

I'd probably go with installing a sub panel as this might be the less expensive route due to the lower cost in copper usage. But to answer your question we have to make some assumptions because you weren't clear...

Are all of the following 30A (5HP) rated current?
planner, jointer, table saw, shaper and dust collection

A good cabinet saw could be 5HP but it's likely that the others are 1-3HP, but you didn't say, so assuming everything requires 30A.
I'm also assuming these devices are hard wired and not cord and plug. DId you know that you can get 240V 20A outlets? You can also get them in twist lock, so in theory you could have 1 240V 20A outlet and plug in different pieces of equipment when you wanted to use them. This is not convenient in a woodworking shop, but could be done.

Planer = 2 conductors
Jointer = 2 conductors
table saw = 2 conductors
shaper = 2 conductors
dust collection = 2 conductors
ground wire = 1 conductor

2+2+2+2+2+0=10 ****, that's > 9 wires (the ground wire counts as a 0 as far as current carrying conductors go. 10-20 wires in conduit requires 50% derating, The NEC cares not that you only intend to run 1 machine at a time...

Assuming (cause you didn't clarify) that all equipment draws 30A.
from the 90C temp rating for THHN wire (90C column is used for derating)
10awg=40A X 50%=20A
8awg=55A X 50%=27.5A (close but no cigar)
6awg=75A X 50%=37.5A

OK, this means that each circuit needs to be wired with 6AWG wire and protected with a 30A breaker. You'd need to have 11 6awg conductor in that 1" conduit and you can't. The maximum allowed fill for 1" EMT is 7 THHN 6awg conductors. You'd have to go up to 1.25" EMT to get your 11 6awg conductors in it...

I don't feel like doing the math on the cost of 70-90 feet of 6awg wire X 11 conductors... But it would be more cost effective to put a subpanel close to the loads and just run each tool in it's own 1/2" EMT with 10awg THHN from the subpanel to the tool.

The math changes a little bit if some of the tools are less than 30A, in that case some of the conductors might be able to be 8 or 10awg.. but the 30A circuit (likely the table saw) and the single ground wire would have to be 6awg.

Now if you ran 2 seperate conduits, placing 2 tools (4 wires) in 1 conduit and 3 tools (6 wires) in the other conduit... 4-6 CCC is rated for 80%
10awg=40A X 50%=32A
8awg=55A X 50%=44A
6awg=75A X 50%=50A

Hey, look at that, if you ran 2 conduits you can use 10awg for everything, so 1 conduit would have 6 10awg wires and 1 10awg ground.
the other conduit would have 4 10awg wires and 1 10awg ground.

So I guess if the conduit was free... But even then if it were me I'd go with the subpanel because I could run 4awg aluminum THHN to the subpanel which 4 conductors would fit in your 1" EMT, breaker it at 65A... cutting costs further... and then have a subpanel close by when I needed to add 120V outlets or lights.... I don't have my conduit fill calculation info handy, but you might be able to do 2-2-4-6 THHN aluminum and fit it in your 1" emt. for a 90A subpanel rating, but you'd have to run the diameter and fill calculation.. and I just did enough math for one night.

Brian

 

[sberry]

The electrician is probably saying that for simplicity and ease of passing an inspection. When wiring multiple motor circuits there are a number of requirements that must be met and its typically easier with smaller motors that are hardwired.

For example, 2 x 2 HP motors, NEC says wire size is to be 12A X 125% + 12A = 27A with maximum breaker 12A X 250% = 30A with all wiring up to thermal protection point being capable of 30A (#10). So if your cords are #14 or #12 you'd have to change them to #10.

If you decided instead to try and run 3 x 2 HP motors, you can't really do it. Wire size would be 12A X 125% + 12A + 12A = 39A with maximum breaker 12A X 250% = 30A again with #10 up to the thermal protection point.

This works best on smaller motors that are higher voltage and 3 phase where you can string a few motors using #12 or #14 wire...

As another poster suggested, a sub panel is probably your best bet. You do not need to size the sub panel for every machine running the same time. Load calculations can come into play and mutually exclusive loads will cancel each other out. You only need enough to power one machine and the vacuum system simultaneously.

they don't need to be 30 a cords, only 14 as long as they are 125 percent of load.

 

[sberry]

The electrician is probably saying that for simplicity and ease of passing an inspection. When wiring multiple motor circuits there are a number of requirements that must be met and its typically easier with smaller motors that are hardwired.

For example, 2 x 2 HP motors, NEC says wire size is to be 12A X 125% + 12A = 27A with maximum breaker 12A X 250% = 30A with all wiring up to thermal protection point being capable of 30A (#10). So if your cords are #14 or #12 you'd have to change them to #10.

If you decided instead to try and run 3 x 2 HP motors, you can't really do it. Wire size would be 12A X 125% + 12A + 12A = 39A with maximum breaker 12A X 250% = 30A again with #10 up to the thermal protection point.

This works best on smaller motors that are higher voltage and 3 phase where you can string a few motors using #12 or #14 wire...

As another poster suggested, a sub panel is probably your best bet. You do not need to size the sub panel for every machine running the same time. Load calculations can come into play and mutually exclusive loads will cancel each other out. You only need enough to power one machine and the vacuum system simultaneously.

they don't need to be 30 a cords, only 14 as long as they are 125 percent of load. Can put multiple motors on 1 circuit. in a shop may put multiple outlets on provided they are not opcd above the outlet and wire.

 

[sberry]

This is common with wood shops.

 

[Marine77]

Thank you Brian. I should have been more specific ( first post won't happen again) the table saw is 3hp 240v 30a, planer, jointer, shaper and dust collection are all is hp 230v 30a. The 1" conduit was free and there would be more than enough to do two runs. I thought about the twist locks but to your point it really would not be convienent. Also I did not mention the length of the runs. The closest to the panel is 25 feet ant furthest would be roughly 80 feet. I am going to have the electrician price out the cost of doing it the sub panel way as it was sugjested by a few gentleman on here. Thank you for your feedback it was very insightful.

 

[Cmreschke]

I personally think at those distances a sub panel costs too much. It would be cheaper to run 2 conduits imo.

 

[ard]

Everything Electrical sounds so complicated in the USA.
Here in NZ everything is either single phase 240v or 3 phase 400v.

LOL

I suspect it is just as complicated, just nobody there talks complicated.

 

[Norcal]

Everything Electrical sounds so complicated in the USA.
Here in NZ everything is either single phase 240v or 3 phase 400v.

If 240V, the line to line voltage would be 415V, if 230V, line to line voltage is 400V.

 

[Justanoldguy]

If 240V, the line to line voltage would be 415V, if 230V, line to line voltage is 400V.

Exactly my point thank you.
Everything has to be complicated over exactness to the point of being overly complicated. KISS.

 

[wyliesdiesels]

Exactly my point thank you.
Everything has to be complicated over exactness to the point of being overly complicated. KISS.

It gets more complicated than whats described here.

In the US, theres 2 different types of 3 phase power- delta and wye, each having 2 different voltages available.

208Y/120, 480Y/277 and 120/240 delta, 480 delta