On to electrical upgrades!

[dbhost]

Now that most of my shop is in good shape, aside from not having a couple of very important tools... band saw, jointer, and lathe... those will come later.

I need to bring new power into the garage as it only has 1 110V outlet in the front wall that is hot 24/7, and another in the ceiling that is on a completely separate circuit that is switched that runs the lighting. Here is what I want to do...

Accross the middle of the ceiling install 3 new outlet boxes, remove the ceiling box with the incandescent bulb fixture and install a new outlet box there. Thus providing power to 2 shop light fixtures each (Yes I want a total of 10 shop lights in my shop). I will double and triple check this, but I believe this is on a 15 amp circuit. What is the power usage of those lights? I would assume they spike when they first fire up the ballast and tube.

I also want to...

Remove the outlet behind the workbench and the single box, replace it with a double box and two receptacles. (Keep the existing GFCI receptacle, just add a second one in the chain after). This is a 15 amp circuit and would run the shop vac, and my benchtop tools.

I want to run a 110V single box to the post between the garage doors to power the A/C. And two double boxes along the left wall to run the stationary tools.

This would leave me with having to run an extension cord for the table saw to the wall. (Aside from putting power into the floor and demo-ing concrete out I have no idea how to get around that).

Should I add an entirely new circuit / breaker or just piggy back off of another circuit?

After adding everything up, there is a good chance I will need my service upgraded to 200amp. Are there any members here from Houston that have had this done? How expensive is that? I know code says I have to have an electrican do that, and I am NOT willing to do that particular job myself...

[MikeMcCoy]

This doesn't answer the rest of your questions but would it help with your table saw if you ran outlets on the overhead? I recently put in a sub panel that gave me 6 circuits and all the power I could ever want. I don't have wall access so except for the bench area, I ran 14 receptacles in the overhead. By the way, I doubt you will need anywhere near a 200 amp panel. I ran 50 amps from my main panel for the sub and wound up with five 20 amp breakers and a single 240v. I kept my 2 lighting circuits on the house circuit.

It sounds like you are moving right along with your setup.

[dbhost]

Yeah, I could run overhead, just put a double box and two receptacles instead of a single and one in the middle for the T.S., I was concerned about running into problems with stock hitting the cord. I was figuring on running the cord along with the DC hose to the wall...

[MikeMcCoy]

I was initially wondering about the cords getting in the way but since I ran boxes every two feet, and made up some short heavy guage drop cords, it hasn't been an issue in the 8 months it's been that way.

[LarryG]

After adding everything up, there is a good chance I will need my service upgraded to 200amp.

Like MikeMcCoy I can't address your main question (I'm not sure anyone could, other than maybe a VERY rough ballpark guess; too many variables), but what do you mean by "adding everything up"? As long as you have some vacant breaker spaces in your panel, it doesn't matter what the various breaker ratings add up to. You just need to add up the maximum total load at any given time and make sure it doesn't exceed the capacity of the mains. It's very common for the breaker ratings in a panel to total up to way more than the panel's rated capacity.

On your lights question, add up the wattage of the bulbs and divide by 120 (volts) to get the amperage. IINM, the rule of thumb for fluorescents is to then add 25% for the ballasts, to get the total load. So if you had 10 two-tube fixtures, using 40W bulbs ...

10 x 2 x 40 = 800w
800 / 120V = 6.67A
6.67A * 1.25 = 8.33A

EDIT: I figured I'd better double-check my increasingly fallible memory with our electrical engineering consultant. He tells me that with the old-timey magnetic ballasts, you did have to add a ballast factor; but now that we have modern electronic ballasts, no more. He calculates a two-tube fixture with 32W T8 bulbs as 60W, three tube as 90W, four tube as 120W.

[poolhound]

This doesn't answer the rest of your questions but would it help with your table saw if you ran outlets on the overhead? I recently put in a sub panel that gave me 6 circuits and all the power I could ever want. I don't have wall access so except for the bench area, I ran 14 receptacles in the overhead. By the way, I doubt you will need anywhere near a 200 amp panel. I ran 50 amps from my main panel for the sub and wound up with five 20 amp breakers and a single 240v. I kept my 2 lighting circuits on the house circuit.

It sounds like you are moving right along with your setup.

I recently did similar to Mike. I ran a 50A circuit from my main panel to a sub panel in the garage. I have 4 20A circuits in there plus the original 15A circuit that was in the garage. I wired in 4 double outlets, 3 in the walls and 1 in the ceiling. Each double has 4 outlets 2 from one circuit and 2 from another. This way wherever I am working in the shop I am close enough to 3 separate 20A and 1 15A circuit. Thats more than enough for me

I angsted for a long time on the best way to do this and in the end decided to do it "Right" and put in all I would ever need including the ability to get 220v from my sub panel in the future if I really need it. If you spend money now on a "stop gap" solution I guarantee you will end up redoing in the future.

[LCHIEN]

the lighting load should be fine for a 15A breaker. All breakers are designed to withstand momentary overloads of 6x or 10x caused by motor starting, lights (fluorescent or incandescant) starting, etc. They are designed as time-sensitive devices, the greater the overload the faster the trip.

[dbhost]

So if you had 10 two-tube fixtures, using 40W bulbs ...

Can you still get 40w bulbs? I see 4 foot 25 watt, and 34 watt T-12s all the time, but haven't seen a new in box F40 T12 flourescent tube since I worked at Ace Hardware back in my college days.

The bulbs I am using / have been using are F34-T12 Daylight White. I think they are either Phillips or Sylvania. They cost more, but I like the light they give off better, more true color, the cool white bulbs give everything a yellowish tint.

[LarryG]

I bought some 40W T12s four years ago, for my previous shop. A bit more than one year ago, when I was buying some additional T8 fixtures for my current shop, I want to say that the 40W bulbs were still available, because I was planning to move the old T12 fixtures and was wondering whether I ought to just forget that idea and buy still more T8 fixtures. I did end up moving five of the old fixtures but almost wish I hadn't, since they buzz horribly whereas the T8s do not.

+1 on the daylight bulbs. Mine are Sylvanias, cost more than the cheapo shop lights themselves, but are absolutely worth the premium over cool whites, which are indeed pretty ghastly.

[dbhost]

Yeah, it's kind of a stupid detail, but the light quality difference is, ahem.. day and night... Sorry that was sort of punny considering we are talking about Daylight White bulbs....

I am pretty sure my fixtures are all T12s. They are, every single one of them, the cheapo 4 footer shop light fixtures from Home Depot. I had some Ace Hardware cheapies in there before, but the ballasts failed on them, and it was cheaper to replace the lamp than the ballast...



Regular price on these is about $9.00, but I have caught them on sale for $5.00 each. I wish I had just spent the $50.00 at once to get all 10 and be done with it, but I thought 6 would be enough. I was wrong...

[just started]

I wish I had a large enough shop space that I could even hang 10 4' dual tube fixtures!!!

[dbhost]

Simple, two car garage, spaced relatively close together. I want LOTS of light...

Once I get the storage stuff out of the garage, and into a shed, the garage / shop will actually be more than roomy enough to do my projects. But with the garden tools, camping gear, smoker, grill, etc... I am sharing space with a LOT of other stuff...

I did some research, and some calculations, and if I turned every power consuming device in the shop on at one time, I would have a 127amp coming from the shop. Not real pretty...

The highest loads that are likely to be run concurrently.

#1. Table Saw @ 15 amps.
#2. Shop Lights. Total 15 amps.
#3. Wet / Dry vac (Dust Collector) 10 amps.
#4. Air Conditioner 10 amps.
#5. Box Fan / Air Filter. 2 amps.

That gives me a total concurrent load of 52 amps.
I also want to bring additional power on a dedicated circuit into the home office as we have a load on there as well. I don't feel too terribly bad about bringing 200amp service into the house considering the electrical load...

I figure the circuit layout should be...
subpanel running a 75 amp main feeding...
20 amps to the ceiling for the lighting, and one drop to the right wall to run the electrical feed for the timer and auto valve on my water purification system. (.2amps)
20 amp breaker feeding 2 drops behind the workbench, and one in the niche where the shop vac is for the workbench and the shop vac. Heavy use here will be the shop vac, jointer, and planer.
20 amp breaker feeding the left wall where the table saw will feed off of, as well as the band saw, Router table, compound miter saw, and lathe.
15 amp breaker to the center post of the garage, one outlet inside, one out. (Since I am in there, might as well run power for Christmas lights right?)...

Am I on the right track?