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Forum topic by SweetTea posted 03-23-2020 11:39 AM 514 views 0 times favorited 15 replies Add to Favorites Watch
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SweetTea

474 posts in 1391 days


03-23-2020 11:39 AM

So I recently purchased 5 new (used) machines and now need to run some new outlets to plug them up to. My question is whether it would be ok to put 2-3 machines on one circuit since they won’t ever be used at one time being that it’s just me in the shop? The machines are a 20amp 3hp jointer, a 20amp Blum hinge boring machine, two 3hp shapers and a 2hp edge sander. My thoughts were to have the shapers, jointer and Blum on one circuit and then the edge sander share a circuit with my old 20amp Delta Unisaw. I can’t stress enough that there will never be a scenario with two machines on at the same time.

I know that for all practical purposes I technically can do this, I just wasn’t sure if voltage loss due to the multiple connections would be an issue or if there are any other things that I should be concerned with?


15 replies so far

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JackDuren

1133 posts in 1691 days


#1 posted 03-23-2020 12:21 PM

You can, but if your wiring you might as well have home runs on each tool. But I have several on one line like the RAS , tablesaw ,edge sander and 6×48 sander….One man shop…

Are you sure you will be the only one in there?

Is this a garage or other?

Your cutting it pretty close on 20 amp machines. You might want to use 10guage….

Conduit?

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Robert

3700 posts in 2212 days


#2 posted 03-23-2020 01:15 PM

When I had my shop wired, my electrician did it that way. Never had an issue.

One thing we did do, rather than having extension cords, we ran the circuit to the machine following the DC drops and mounted the outlet directly on the machine housing. My machines don’t get moved so it worked out for me and was easier than 220 made up lextension cords to an outlet.

-- Everything is a prototype thats why its one of a kind!!

View tvrgeek's profile

tvrgeek

941 posts in 2380 days


#3 posted 03-23-2020 01:44 PM

I suggest consulting an electrician and your local code. Codes vary.

When I wired my shop and got inspection, they did not ask what was plugged in where. My DC and compressor will share one 30A circuit when I move them as I would never use both. I will add another outlet for a bigger welder as again, it would not be used with either other tool. My TS ,BS, and Jointer share a 30A (10 ga) circuit as again, they would never be used at the same time. I wish I had more space in my sub-panel. I would home run if I could.

As some of the REAL electricians replied to other threads recently, you need to look at the motor plates to know what size circuit they really need. All those machines you mention sound like they need at least a 30A 220.

If exposed, must be armored. BX or thinwall. My TS is fed from a ceiling drop and there are specific requirements on the wire and strain reliefs.

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JackDuren

1133 posts in 1691 days


#4 posted 03-23-2020 02:01 PM



I suggest consulting an electrician and your local code. Codes vary.

When I wired my shop and got inspection, they did not ask what was plugged in where. My DC and compressor will share one 30A circuit when I move them as I would never use both. I will add another outlet for a bigger welder as again, it would not be used with either other tool. My TS ,BS, and Jointer share a 30A (10 ga) circuit as again, they would never be used at the same time. I wish I had more space in my sub-panel. I would home run if I could.

As some of the REAL electricians replied to other threads recently, you need to look at the motor plates to know what size circuit they really need. All those machines you mention sound like they need at least a 30A 220.

If exposed, must be armored. BX or thinwall. My TS is fed from a ceiling drop and there are specific requirements on the wire and strain reliefs.

- tvrgeek


You have to be careful putting a 30 amp breaker on a 20 amp tool.

View splintergroup's profile

splintergroup

3645 posts in 1953 days


#5 posted 03-23-2020 02:58 PM

Personally I’ll rewire any motors over 1HP to run on 220. I leave the fractional HP stuff for common 110V circuits and let my bigger stuff use the 220V circuits with the heavier conductors and greater capacity.

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therealSteveN

5545 posts in 1305 days


#6 posted 03-23-2020 03:15 PM



Personally I ll rewire any motors over 1HP to run on 220. I leave the fractional HP stuff for common 110V circuits and let my bigger stuff use the 220V circuits with the heavier conductors and greater capacity.

- splintergroup

My shop is the same way. I have no doubt overdone it, but I feel warmer and fuzzier as it is. I have a direct line to every 220 tool as well, and have 4 gang 110 circuits every 8 feet around the perimeter, they run off 3 different 20Amp lines, and leapfrog so every third one is the closest to repeating, I have a longer reach than some, but not over 20 foot…. :-)

I too have a “one man shop” and about every third time I’m out there, there is at least one other person who has dropped by, and is actively using other equipment as I am working on something. Stuff happens…...

-- Think safe, be safe

View ibewjon's profile

ibewjon

1514 posts in 3524 days


#7 posted 03-23-2020 03:42 PM

Breaker and wire size for motors is figured differently when motor is protected by a magnetic starter with overload protection. For example, a 3 hp single phase motor, in 240 v, full load current 17 amps, can be operated on 12 awg minimum wire size with a 35 amp thermal magnetic breaker. Just because 12 is minimum, it doesn’t mean you can not increase wire size. Bigger is better for motors. All of my 240 circuits are 8 or 10 awg. All of my large motors have magnetic starters. ( Not magnetic switches with no overcurrent ). Large wire and starters are less expensive than new motors, especially some of the specific motors that are no longer available because of so many manufacturers closing up. After seeing my post, it was at the same time as TV, but should have been posted after his. We are both talking about increased breaker size due to inrush current.

View tvrgeek's profile

tvrgeek

941 posts in 2380 days


#8 posted 03-23-2020 03:42 PM

Quite incorrect I believe. Inductive motors have huge inrush currents. The branch needs to be far larger than the “run” current. The breaker is there to protect the building, not the tool. Might I suggest reading the “switch is a switch” thread and the one on the gentleman installing a 5 HP compressor. Licensed electricians had their feedback. If you search the WEB, you can find out how to read motor labels and determine the minimum branch requirements.

I suggest consulting an electrician and your local code. Codes vary.

When I wired my shop and got inspection, they did not ask what was plugged in where. My DC and compressor will share one 30A circuit when I move them as I would never use both. I will add another outlet for a bigger welder as again, it would not be used with either other tool. My TS ,BS, and Jointer share a 30A (10 ga) circuit as again, they would never be used at the same time. I wish I had more space in my sub-panel. I would home run if I could.

As some of the REAL electricians replied to other threads recently, you need to look at the motor plates to know what size circuit they really need. All those machines you mention sound like they need at least a 30A 220.

If exposed, must be armored. BX or thinwall. My TS is fed from a ceiling drop and there are specific requirements on the wire and strain reliefs.

- tvrgeek

You have to be careful putting a 30 amp breaker on a 20 amp tool.

- JackDuren


View CaptainKlutz's profile

CaptainKlutz

2993 posts in 2225 days


#9 posted 03-23-2020 04:30 PM

SweetTea

Do you still have 3 phase power and 30+ other tools in shop?
Why do you continue to ask a hobby wood working forum about power in a commercial shop?
If you call the same electrician you used for last 5+ threads you started regarding shop wiring, he/she can hook it up as required by all the codes that regulate your shop.

IME – only way you can share power in a commercial operation with more than 1 employee working, is when the tools use separate, but interlocked disconnect methods.
They can use power cords that are plugged in when needed, or hardwired machines need separate disconnect switch with one machine at a time protocol. The issue is not power demand per NEC codes, the issue is shop safety and power lock out in OSHA codes when tool is supposed to be disconnected from power, like when being setup (knife/paper change).

Don’t forget to tell your insurance company about new equipment. They also might have an opinion on power sharing that matters more than anything we post in this forum. Have seen insurance inspectors charge higher premium when power tools share over burdened feed circuits. It has always been cheaper overall when each machine has separate power feed, and building is properly wired without short cuts. YMMV

Best Luck.

-- If it wasn't for bad luck, I wouldn't have no luck at all, - Albert King - Born Under a Bad Sign released 1967

View clagwell's profile

clagwell

205 posts in 523 days


#10 posted 03-23-2020 04:45 PM

Well, I’m going to take a novel approach here and try to answer the actual question SweetTea asked:

I know that for all practical purposes I technically can do this, I just wasn’t sure if voltage loss due to the multiple connections would be an issue or if there are any other things that I should be concerned with?

- SweetTea

If done properly the extra connections will have negligible influence on the voltage drop. You can calculate that the usual way using the length of the wire and don’t need any adjustment for the extra outlets.

The only other concern I would have has already been addressed:

I can’t stress enough that there will never be a scenario with two machines on at the same time.

So, assuming all of your wiring is appropriate to the load the added connections will be fine.

-- Dave, Tippecanoe County, IN --- Is there a corollary to Beranek.s Law that applies to dust collection?

View ibewjon's profile

ibewjon

1514 posts in 3524 days


#11 posted 03-23-2020 04:52 PM

Captain thanks for noticing this is a perpetual question from the same person. I now remember the previous threads. I am out of this. Again. Call a licensed contractor.

View JackDuren's profile

JackDuren

1133 posts in 1691 days


#12 posted 03-23-2020 05:01 PM

It’s an open forum. Just ignore the question. Don’t make a big deal out of it…

View CaptainKlutz's profile

CaptainKlutz

2993 posts in 2225 days


#13 posted 03-23-2020 10:56 PM


It s an open forum. Just ignore the question. Don t make a big deal out of it…
- JackDuren

I will bend over backward to help those that need help in this forum. But when someone, anyone, keeps asking commercial power wiring related questions, even admits they have 3 phase power and full commercial shop filled with 3 phase tools, I become suspect of being used.

In 3.5 years of membership, OP has shared nothing within the forum. No projects, no advice, no help to others. Majority of posts we see are questions looking for free advice on electrical wiring. When a user does not give back to a forum they constantly use for specific information to their situation, over and over;
We are all being used.

Plus OP has shown in past they are not qualified to do the electrical work DIY. When any person has history of asking to do scary things with shop power in these forums, everyone needs to be made aware they are potentially helping someone hurt themselves or others.
Be surprised if anyone who has NEC training and owned the responsibility for electrical safety in a commercial operation would disagree with my concerns?

Besides, I answered the OP question, CALL AN ELECTRICIAN. They have many more safety issues than voltage drop by sharing power between tools in a commercial operation.

#unwatch

-- If it wasn't for bad luck, I wouldn't have no luck at all, - Albert King - Born Under a Bad Sign released 1967

View SweetTea's profile

SweetTea

474 posts in 1391 days


#14 posted 03-24-2020 11:07 AM


It s an open forum. Just ignore the question. Don t make a big deal out of it…
- JackDuren

I will bend over backward to help those that need help in this forum. But when someone, anyone, keeps asking commercial power wiring related questions, even admits they have 3 phase power and full commercial shop filled with 3 phase tools, I become suspect of being used.

In 3.5 years of membership, OP has shared nothing within the forum. No projects, no advice, no help to others. Majority of posts we see are questions looking for free advice on electrical wiring. When a user does not give back to a forum they constantly use for specific information to their situation, over and over;
We are all being used.

Plus OP has shown in past they are not qualified to do the electrical work DIY. When any person has history of asking to do scary things with shop power in these forums, everyone needs to be made aware they are potentially helping someone hurt themselves or others.
Be surprised if anyone who has NEC training and owned the responsibility for electrical safety in a commercial operation would disagree with my concerns?

Besides, I answered the OP question, CALL AN ELECTRICIAN. They have many more safety issues than voltage drop by sharing power between tools in a commercial operation.

#unwatch

- CaptainKlutz

I still have my equipment but a new shop and I have shut down the cabinet building stuff to go full time into buying and selling real estate and such. I will keep my equipment and maintain a shop so that I can do my own cabinets when needed. No 3 phase power. I do have an RPC but it is not the subject of this thread. I am not working with anything more than simple 220v standard residential power. I live in a very rural area with no code inspections and while I will have the work done by a licensed electrician I still like to get input on the game plan before I start. Nothing wrong with that. There are not a whole lot of qualified industrial electricians in my area. None that I am aware of. So I am making due with a residential electrician and while I trust him to do all of the actual wiring, conduit, and connections I still want to be informed myself so that I can better understand and communicate my intentions to him.

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tvrgeek

941 posts in 2380 days


#15 posted 03-28-2020 11:01 AM

To be clear, my comment post 8 is in reference to post 4. Not 7. We have the expertise of at least two real electricians here!

$300 in materials just to upgrade two branches to 30A to get ready for new tools. Not a place to scrimp.

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