Electricity Suggestions for Shop

Evening all from snowy Vancouver Island.

I need some electrical advice. I know some of this has been touched on before, but I'm asking again so I can understand it clearly. Give it to me please in little words. Whatever I used to know about electricity I forgot in 1984.

I had a nasty surprise this morning when I plugged in my two brand new infrared heaters and found that if I ran them at the same time, plugged into 2 different outlets across the room from each other, it threw the breaker. :bang:

So I include some photos. Yes I know it's a mess. Not sure if they'll come out in the right order, but there are 2 photos of the shop in general, one of the 2 heaters, and 2 of the electrical box which is in the garage :thumb:

shopjan1211.jpg

shopbjan1211.jpg

shopcjan1211heaters.jpg

shopdjan1211epanel.jpg

shopejan1211epanelb.jpg

So my question is, before I have an electrician come over to increase my power and outlets, can you tell me what I need for a) power and b) outlets and yes, I'm going to ask for 220 too.

I currently have 3 wall outlets only, not including 1 dedicated to the vacuum system. And I have 2 ceiling outlets, one for each electric garage door, although I will be taking out one or both of them.

And Rob, no I do not want to wire it myself. So unless you're flying out here to do it for me, :wave: I'm hiring somebody. So tell me what to ask for. Okay?

thanks a million,
cynthia :)
 
How many watts are each of the heaters? If you don't know the wattage, look for the label and see if it says there or if it lists the amperage, either one will be fine.
 
- how many watts are the heaters?
- are the ceiling outlets on the same breaker as the wall outlets?
- if not, maybe you can plug one into that for now.
- how many watts is the central vac, is it on a dedicated breaker? Just wondering if you could share that outlet with a heater, again, just for now.
- The photo is a bit unclear but I think I see 4 open spaces in your electric panel, so you can probably do at least one 220 circuit, and two other 110 outlets.

- at least your panel is in the garage, so it shouldn't be TOO difficult or too expensive to pull a couple circuits.
(I'm not an electrician either...)
 
Okay, the vacuum is 11 Amps and where it's plugged in there's tape over the other plug in to indicate I assume not to use it. Don't know if that's a dedicated circuit.

The heater book says that with the lamp and heating element on, the heater uses 1500W.

When that one breaker was thrown, I had on the
a) overhead lights, i.e. 2 light bulbs,
b) 2 Makita battery chargers on side of the room and
c) some small portable flood lights in the same outlet as b),
d) 2 heaters, one plugged into one overhead outlet alone and the other, alone in another wall outlet.

Everything went off as soon as I started the second heater.
 
From what I could read on the panel labels, the vacuum is on it's own circuit. Looks like the rest of the garage is on another from what I can see.

Take 1500 divided by 120 Volts, you're looking at needing around 12.5 amps for each heater when they are running full blast. Could probably get away with a 20 amp circuit dedicated to the two of them, but it may trip all the time when they are running full blast. I'd probably suggest a 20 amp for each, then share with some other plugs that won't use much power, such as your chargers.

They make breakers that allow additional taps for 120 volt circuits if the panel runs out of space. Basically it has two breakers built in the same space as a single breaker. Will have to check with the electrician to see if they meet code in your area. I'd still suggest a sub-panel run to the garage then run the new circuits from there.
 
Sorry, didnt' see that the panel is in the garage...Unless you've just got too many wires in the existing panel, a sub-panel wouldn't be needed unless you run out of breaker spots and can't use the 2 circuit breakers that go in a single space. :wave:
 
Well I dont envy you running those heaters Cynthia, thats 3Kw per hour and I dont know what you paying in BC but i would not run those babies when i dont need them if i were you.:D

I see the blank spots in the panel and my question is, is this going to be your shop now on a permanent basis. That is are we getting geared to camp there for a good while. Cause if so I would rather not take up all those slots but rather only take one up for a sub panel which can be placed in a convenient spot to suite you and the altered layout of the room from before. This would allow expansion to more breakers where you can still have your 220V and get to have more dedicated or at least less receptacles per circuit.

I think its important that you fundamentally understand why things are tripping now.

So even though i do not wish to confuse you.

Keep this rough formula in mind.

P = V times I

Now P equals the power in watts

V equals the supply voltage which could be 120v or 220v

I equals the current that is flowing measured in amps.

So lets for a moment consider your heaters.

1 heater is 1500w at the rated voltage of 120v

What that means in current terms is that when its on full blast it will have around P/V 1500 divide by 120 equals 12.5 amps running through it.

Now figure, the normal receptacle is rated for a max of 15 amps. They will from a safety aspect carry more but that is dangerous they were not designed to do that. So when you have two heaters on one receptacle you are exceeding the current rating for that receptacle.

Ok you say but Rob i put it into two different receptacles and it blew the breaker.

Here is why. In our codes we are allowed more than one receptacle. Its actually a crazy number that you can go up to and i wont quote it here. The premise is though that you aint gonna load them all up at once and if you were to be doing that, then it would most likely be very small indiviual loads such as say Cell phone chargers or computers or a printer etc. Most of these devices consume power in the low hundreds of watts not 1000's as you heaters or machinery will do.

So to protect us and again in my little dig to the safety and economic expedience here in NA we rely on the use of a 15 amp circuit breaker at the end of the receptacle line. But this means that the sum of all the currents flowing in all the receptacles on that circuit should be preferably under 15amps. When you have your two heaters on and connected to receptacles or extension cords that essentially all run off the same circuit breaker you can see that just the two heaters alone would trip the 15amp breaker. Now its likely that if that was a garage previously that they might have put a 20Amp breaker in the panel for the receptacles to cater for something like a welder which will have a surge current. Regardless you are still exceeding the load and that is totally unsafe.

Its important to your safety (and this is why i campaign that people get a bit of this experience ) that you understand this regardless of the aspect of whether you do your electrical or even need an electrian or are going to make any changes to your electrical. You should understand these things simply as a homeowner and excuse me for saying this but more as woman because of things like curling tongs and hairdriers.

So when you look at what you need in a shop my suggestion is less receptacles on one circuit and more individual circuits where you can run machines without them sharing the load on the line with some other device you might want to run such as a shop vac.

I think while i am on it i should let you understand how this overloading a ciruit affects your safety. Simply that when you draw too much current from a line there is heat dissapated in the wire due to the resistance inherent in the wire. Things like joints along the way where they get made through a screw down are also a point of resistance. This resistance and heat when a high current is drawn can get to the point where it can cause combustion of other materials or at a minimum smoldering and the consequential smoke. This is why i hate extension cords. Inevitably people are cheap and without an understanding of the whole process by a cord and then because it has the receptacle connections think they can run any old thing on it.

If you take your heaters for example and run them on a thin gauge extension cord you will feel that extension cord getting warm.

This is also something which is not often mention either about the benefit of running 220v.

If you apply the same equation and say that your heaters were of the 220v type then P=V.I so we have 1500w / 220V = 6.8 amps. Note the current is halved. I aint gonna get into phases etc because to want to keep it simple so the others here dont go biting my head off because i am trying as best as possible to keep this basic.

So you need to think about deciding whether you have the finances and desire to do what you want or just what you need right now.

Remember the fundamental cost with any contractor is being on site. The additions to the scope of work are only then a function of the direct material and labor associated with it and margin. What you dilute by adding to the scope of work is his overhead to be on site. This is something people do not understand about the trades. We get a guy coming to service the gas stove or the dishwasher or refrigerator and we balk at the call out charge. We dont think of the time it takes the guy to get to us and the travel costs and the time back to where he was. Never mind his tools, training and motor vehicle costs right down to car washes and winshield washer. Whether he does one circuit breaker or 10 thats fixed. But we all are living in tight budget times so you must make the call for that.

As to what you put in i think you need to spell out a little of what direction you are going.

1) Now
2) Long term and do you want to cater for long term even if you do not do the whole thing.

If you do then you should spell out everything thats gonna be in this shop and lets estimate the power for each item

Just to help you

Think on machinery alone we generally have the following minimums

1) Drill press
2) Table Saw
3) Planner
4) Some have mitre saw or radial arm or even both. I know of some with two mitre saws and a radial arm saw.
5) Bandsaw
6) Jointer
7) Heavy duty router like 3.5 hp
8) Dust collector
9) shop vac
10) Heaters regardless of the type most have a requirement for electric except the woodstoves.
11) Lighting
12) Yes some of us have lathes.:rofl:
13) Miscelaneous power tools and battery chargers and radio or amp.
14) Air cleaner or air scrubber what ever you call it.
15) Some have airconditioning which is another little power hog depending on its size.

Now there will be a difference between what the individual machines draw as far as current is concerned and here we get to the dreaded marketing lies that many of these tool and machine manufacturers play with and that is HP or horsepower. There is a mathematical formula to calculate the current from he HP given the voltage but i would prefer you look at the motor or specification of the machine for the actual current rating rather than rely on the marketing lies so i will not volunteer the Hp calculation just so errors are minimized.

There is a range for each of these machines and its the typical item that drives our machine prices. (Not in Canada. Here we get ripped for 1HP what the US pays for 3 or even more) So i am more refering to a purchase from say Grizzly or Delta than Craftex( Busy Bee).

You need to think about your wish list here and take into account your current machines.

This is not as ardous as it sounds. Most of us are pretty much in a narrow bracket and budget and common sense and our work we do drives it.

If the general hobbyist was a Karl making cabinets as an occupation then it would be different. In my case i tried to be middle of the road.

Dont be surprized by the fact that all this power quickly adds up but this is why i recommend a sub panel. When you start to add proper dust collection and consider that this unit will most likely be running with a machine and here you have to take your worst case machine which in my case is my jointer, then add lights and either heater or aircon and air cleaner then you have my typical maximum load. With my dust collector being 220V and my jointer being 220V i manage to get in under the wire when I am in either of the above states. Of course that will be when my dust collector is hooked up but that is what my design caters for. My panel is on a 60Amp breaker from the main house panel.

So i think i have done enough confusing or thought raising for the moment. There is no easy quick just do this answer. You need to digest this and discuss with Brian. Because where is he getting his power from for his shop? Decide on your priorities. There is a low cost short route here as a temporary interim solution there is a middle of the road and there is the full hog.

Enjoy i am now glad i am past this evolutionary point although i wish i had added even more circuits to my shop and i wish i had put them on the surface like others.

One thing for sure, if you get 220v make sure to run a receptacle to both sides of the shop. I had a layout planned and laid out the receptacles accordingly. Now i am sorry.

Good luck let us know what you decide and we can help some more.

Remember my Dads saying that echos in my ears hourly, "Act in haste and repent at you leisure" :rofl::rofl: Boy i hate that saying.:D
 
What kind of advice are you looking for Cynthia? I assume you realize that everything is currently on the same circuit.

If you are asking what should be done to increase your electrical capacity in there, then the first step is to make a load list. That is a list of all your motor loads, plus the loads for any heaters, etc. The motor loads would include all current and future loads such as all those major tools you want to buy. Put the down amperage or the horsepower of each motor (big tools, not hand tools). You then find an electrician you trust and have him come over, show him the list and talk a little about what motors would run at the same time (worst cast scenario), the number and type of receptacles you would like and where. He will look at your current panel, probably ask many questions, such as do you want the wiring hidden or is conduit run on the exterior of the wall OK with you. Then you will ask him many questions. Both of you will finally come to an understanding of what should be done. He will then go away and work up a price and give you a written quote. You will then ask us here what he proposed to do and for how much. We here will all disagree on various aspects of the proposal and maybe even pricing. Much confusion for a while and then a moment of clarity will hit you and you make your decision. We then have many posts from you of the project progress and live vicariously though your experiences while constantly bugging you for more photo's.

I can't wait!:D
 
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:dunno: how do i figure that out? No we don't have any gas, no natural gas, and no propane. Just electricity.

Well that means you can't re-purpose those breakers. Have a subpanel put in for your garage circuits.

Make a list of what you are going to run, how many of the tools will run at the same time (think table saw and dust collector), decide if you want drop downs from the ceiling, do you want a bank of outlets over your bench for power tools. Besides your overhead heating consider having outlets wired in for lighting in the future.

A good electrician should walk you through these questions and provide the installation per your local codes. Are there any other woodworkers in your area that might have hired an electrician? Tap them for referrals.

Cheers,
 
Don you know we have a guy in Canada named Mike Holmes. Now i only have two heros, and he is one of them. Mike makes the point and if you buy his book which was given to me as a gift, you will see that Mike makes the point about home owners educating themselves before they call in the trades. That is half their responsibility then at least they know what they getting and know why they paying.

As he keeps saying when people in our area think they can hire a great contractor and finish their basement to a five star standard and expect to put a bathroom with shower and all sorts in the basement and have it done for $15K they need their head read. If they took a moment to educate themselves they would have some idea of just what the materials cost never mind the labor and finishing.

So Cynthia asked to be enlightened and as other have done for me i have tried to do for her. :):p:twocents:
 
What kind of advice are you looking for Cynthia? I assume you realize that everything is currently on the same circuit.

If you are asking what should be done to increase your electrical capacity in there, then the first step is to make a load list. That is a list of all your motor loads, plus the loads for any heaters, etc. The motor loads would include all current and future loads such as all those major tools you want to buy. Put the down amperage or the horsepower of each motor (big tools, not hand tools).

You're very sweet, Bill. What I'm wondering is how many receptacles do people need and how many circuits? And how many 220 outlets--I think Rob said at least 2, on each side of the shop.

Yes, it's clear to me now that everything is on the same circuit, and that that's not working for me.

I'm going to move over to Rob's post and respond to some of his comments.

thank you
 
Well I dont envy you running those heaters Cynthia, thats 3Kw per hour and I dont know what you paying in BC but i would not run those babies when i dont need them if i were you.:D

Keep this rough formula in mind.

P = V times I

Now P equals the power in watts

V equals the supply voltage which could be 120v or 220v

I equals the current that is flowing measured in amps.

1 heater is 1500w at the rated voltage of 120v

What that means in current terms is that when its on full blast it will have around P/V 1500 divide by 120 equals 12.5 amps running through it.

You should understand these things simply as a homeowner and excuse me for saying this but more as woman because of things like curling tongs and hairdriers.

So when you look at what you need in a shop my suggestion is less receptacles on one circuit and more individual circuits where you can run machines without them sharing the load on the line with some other device you might want to run such as a shop vac.

This is also something which is not often mention either about the benefit of running 220v.

If you apply the same equation and say that your heaters were of the 220v type then P=V.I so we have 1500w / 220V = 6.8 amps. Note the current is halved.

So you need to think about deciding whether you have the finances and desire to do what you want or just what you need right now.

Remember the fundamental cost with any contractor is being on site. The additions to the scope of work are only then a function of the direct material and labor associated with it and margin. What you dilute by adding to the scope of work is his overhead to be on site. This is something people do not understand about the trades. We get a guy coming to service the gas stove or the dishwasher or refrigerator and we balk at the call out charge. We dont think of the time it takes the guy to get to us and the travel costs and the time back to where he was. Never mind his tools, training and motor vehicle costs right down to car washes and winshield washer. Whether he does one circuit breaker or 10 thats fixed. But we all are living in tight budget times so you must make the call for that.

As to what you put in i think you need to spell out a little of what direction you are going.

1) Drill press
2) Table Saw
3) Planner
4) Some have mitre saw or radial arm or even both. I know of some with two mitre saws and a radial arm saw.
5) Bandsaw
6) Jointer
7) Heavy duty router like 3.5 hp
8) Dust collector
9) shop vac
10) Heaters regardless of the type most have a requirement for electric except the woodstoves.
11) Lighting
12) Yes some of us have lathes.:rofl:
13) Miscelaneous power tools and battery chargers and radio or amp.
14) Air cleaner or air scrubber what ever you call it.
15) Some have airconditioning which is another little power hog depending on its size.

You need to think about your wish list here and take into account your current machines.

Dont be surprized by the fact that all this power quickly adds up but this is why i recommend a sub panel.

Remember my Dads saying that echos in my ears hourly, "Act in haste and repent at you leisure" :rofl::rofl: Boy i hate that saying.:D

Rob, thanks for all that info. :rofl: :rofl: seriously, I knew I would have to give you a good listening to!

So I edited your post a little to respond to a few points. Yes, thanks I understand (and remember now) your equation. No, I hadn't thought of the cost of running them. I do intend to put in a wood heater sooner rather than later. Yes, I see now that they are all on one circuit. Yes, I know that extension cords are an issue.

I need one extension cord for one heater and I bought the heaviest duty one I could find.

Plans? Let's think short term. My dad says, "in the long term we'll all be dead." I plan to be doing this stuff for a long time. Maybe not all day every day but enough that I don't want to have to wonder "which machines can I turn on today?"

I agree that it's useful to understand what's going on. I know it's expensive to get a trade, but I don't know how much time it would take him to a) add 220 and 2X outlets for it b) add a sub panel c) add several more circuits and d) and several more outlets. So it's impossible for me to imagine what that will cost? I'm not insulted by the hair dryer comment, but I don't use one and don't even have one.

LOML has a separate power source and separate bill for his shop, and it's unrelated to the house. My shop is in the garage, so it's part of the house.

Is there a rule of thumb for how many watts or amps these things typically draw? In your list below I made a few comments.

1) Drill press (yes, soon)
2) Table Saw (yes, and will probably move to bigger one)
3) Planner (probably stick with small DeWalt 735)
4) Some have mitre saw or radial arm or even both. I know of some with two mitre saws and a radial arm saw. (have 1 CPMS and that's plenty)
5) Bandsaw (yes eventually)
6) Jointer (yes, probably big one)
7) Heavy duty router like 3.5 hp (maybe just a 2.X hp)
8) Dust collector (yes eventually)
9) shop vac (yes now)
10) Heaters regardless of the type most have a requirement for electric except the woodstoves. (electric now, wood later)
11) Lighting (yes and need more)
12) Yes some of us have lathes.:rofl: (yes, eventually)
13) Miscelaneous power tools and battery chargers and radio or amp. (yes)
14) Air cleaner or air scrubber what ever you call it. (probably)
15) Some have airconditioning which is another little power hog depending on its size. (no)

Now correct me if I'm wrong, but the tools in red will only run one at a time, no? But lights, dust collection, and heating and misc will run together right? And we already know those 2 heaters are drawing almost 14 amps if they're on together....which they won't be anytime soon....:rolleyes:

So for those with all these things above, how many circuits do you have, how many outlets do you have and do you think you have enough?
 
Bill wins the thread. :rofl:

Cynthia, the number of outlets you'll ultimately need depends on the tools you end up owning. That said, your shop will likely be pretty typical of most others, including mine.

My garage initially had two 15 amp 120v circuits. These covered the overhead lights, wall outlets, the ceiling outlet for the garage door opener, a few outdoor spotlights, and all the power to the laundry room (washer, gas dryer, and overhead lights). Even with all that stuff attached to those circuits, I was able to run a tablesaw, bandsaw, 110v dust collector, 120v compressor, shop vac, router table, and all the other typical shop gadgets and chargers. The only times I ever tripped a breaker was if I used the tablesaw when the washing machine was running. I also had to be judicious about using my electric space heater.

When I upgraded my shop power, I installed a pair of 20 amp 240v circuits, and a pair of 20 amp 120v circuits. (I later added a 40 amp 220v circuit for a large compressor.) Between my two existing 15 amp circuits and the new 20 amp circuits (both 120v and 240v), I can now run my tools and accessories at will without tripping a breaker. Granted, if I turned everything on at once, I might run into problems, but in a one-man shop that simply doesn't happen.

I'll second the previous advice to compile a list of your anticipated tools, establish a rough guess of the total amperage you'll need (including what tools might be running at the same time, i.e., tablesaw, dust collector, and heater), then get an electrician to look at your specific installation and make recommendations. Then, pretty much everything Bill said about debates and photos and moments of clarity will happen. :D
 
...Is there a rule of thumb for how many watts or amps these things typically draw?...

Why, yes. Yes there is. :D Actually, you'll need to look up the HP or amperage of the machines you have in mind, but once you have those numbers, here's the math:

HP X 746 Watts
---------------- = Amps
Voltage

In other words, for a 1 HP motor running on 120 volts:

1 X 746
------- = 6.2 amps
120

Or a 3 HP motor running on 240 volts:

3 X 746
------- = 9.3 amps
240

A few things to note:

These are just general guidelines. Some motors are less efficient than others, so they get fewer HP out of an amp of power.

This formula covers the amperage the motor pulls when it is running. When it first starts up, though, it can draw a lot more, sometimes double the running amps. So in a hypothetical situation, although that 3 HP 240v motor in the example above could run on a 10 amp breaker, it would be likely to trip it when the motor started.

Some tools (routers and shop vacs come to mind) use inflated HP ratings. That 3 1/4 HP router? Look at the amperage it pulls (probably around 15 amps), and using the a version of the formula above you'll see 3 1/4 HP is a bit of a stretch.

Volts X Amps
------------ = HP
746

120 x 15
-------- = 2.4 HP
746
 
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