My shop has formed piece by piece, without always thinking about how the shop would work best but more where can I fit more stuff. It's easy to get complacent.
With only two duplex receptacles, which I added when I moved in, I spent a lot of time unplugging a tool and plugging in another tool. I'm not using tools simultaneously, I just use a lot of tools consecutively. How much more could I build without spending time managing cords?
I planned to replace the two duplex receptacles with quad receptacles and add another quad mounted to a joist above my work area to keep cords out of the floor. As I was determining if this was enough I decided to streamline my shop by rearranging everything. I should build the receptacles around my shop, not my shop around the receptacles.
 |
| Plenty of receptacles for all the equipment. |
The end result is upgrading from (2) duplex receptacles to (11) duplex receptacles. I'm not unplugging anything!
While I'm at it, I'm going to add a 240 volt receptacle for a welder in the future.
One fortunate aspect of this project is that the breaker box is on the other side of one of my shop walls which reduced how much wire I needed. If the breaker box were on the opposite side of the house, I would have created a sub panel for the shop.
Here's a great site for things to consider when preparing an electrical setup for a shop.
Electricity Basics
Electricity is dangerous. You have to be careful. While I feel comfortable wiring a receptacle or a light, working in a breaker box is a different story. A breaker box has a lot higher voltage running to it than a receptacle with a much higher current. Even if you have a main breaker, the stakes for screwing up are higher. Contact an electrician if you are working in the breaker box.
A metaphor for volts and amps, volts is the size of the pipe and amps is how much water flows through that pipe.
With shop equipment, a saw may require 20 amps at 120 volts, but only 10 amps at 240 volts. Doubling the power, halves the current draw. The only power tool in my shop I could convert to 240 volts is my table saw and I just don't' have the need.
Breaker and awg (American Wire Gauge) pairing:
15 amp - 14 awg
20 amp - 12 awg
30 amp - 10 awg
40 amp - 8 awg
50 amp - 6 awg
- (9) 20 amp receptacles - I'll reuse the (2) receptacles I already have and reuse one of the single gang boxes. It's cheaper to buy a 10 pack, than to buy 9 individually. I'm using 20 amp receptacles as that's my breaker rating.
- (5) two-gang boxes
- (5) two gang box receptacle covers
- (5) strain relief connectors
- 12 gauge 3 strand wire You will need this to add receptacles. With a 20 amp breaker, wiring needs to be a minimum of 12 awg. A 15 amp breaker and 15 amp receptacles would only need 14 awg wire. I already had quite a bit of wire which reduced the total cost. I only bought 25 feet. Needing all the wire, could increase the cost of the project by $100
- Plastic anchor and screw to attach box to CMU block wall, depending on material
- 1" drywall screws to install box to joist
- 1/2" conduit - I'm reusing the conduit I have, but I'm also adding two boxes on the wall so I'll need more
- (2) 90* conduit elbow
- (2) 1/2" conduit couplers
- (1) conduit connector
- (2) Single hole conduit straps
- Wire nuts sized to fit - I needed one to fit (4) 12 gauge wires
- 240 volt receptacle
- 10 gauge 4 strand wire by the foot or 25' of wire
- (2) 20 amp breakers
- (1) 30 amp breaker
- Flat head screwdriver, phillips screwdriver to remove existing boxes, junction box covers, etc. My boxes were screwed into a block wall with plastic inserts.
- Test Light or multimeter to confirm that power is shut off. Flip the breaker off and DOUBLE CHECK. My receptacles are on a separate breaker than the lights.
- Painters tape - I used this to mark box positions. You could mark on the joists with a pencil
- Drill with 5/32" bit for drywall screws and a masonry bit if drilling through CMU sized to plastic insert
- 1/2" wood bit to drill through joists
- Wire strippers/ cutters
- Electrical tape
- Pliers to straighten out wire ends and to remove knockouts
- A bucket or stool to reach joists
- $350 range starting with nothing. I spent $200, but I already had a lot of materials.
For the receptacle upgrade, you will need to flip a breaker and then test EACH receptacle to make sure you flipped the right breaker and that your breaker box isn't mislabeled. Double check, electricity is no joke.
If your electrical breaker box isn't labeled well, this may take a while. My breaker box was not labeled well when I moved in, but over time I've updated it.
My lights and receptacles are on different breakers so at least I still have light while doing this project.
My receptacles are on the same breaker as the room above which isn't ideal. I have a circuit that used to be connected to a baseboard heater that will become the dedicated circuit for my shop. While I have a lot of receptacles on one breaker, the load isn't going to be any higher than when I just had two receptacles. I'm still using the same amount of tools at any one time.
Before rewiring anything I checked the breaker and voltage. The base board heaters run a double pole breaker which means they output 240 volts. I contacted an electrician to replace the 240 breaker with two single pole 20 amp 120 volt breakers. With 20 amp breakers, the minimum wire size is 12 awg.
One breaker runs the shop receptacles, and one is a dedicated circuit for the dust collector receptacle. As I discovered while adding dust collection, it needs it's own circuit. Fortunately I had an entire sub panel free. It used to power baseboard heaters which have since been removed.
Most panels have a free circuit, and there are tandem breakers that can give you two circuits in one single pole slot.
I also decided to run a 240 volt receptacle while I was at it on one of the other abandoned 240 volt baseboard heater breaker. I upgraded the breaker to 30 amps from 20. I used 10 gauge wire which matches that size breaker. If I was going to install a 40 amp breaker, I would use 8 awg, a 50 amp breaker would require 6 awg. For the welding I would do, 30 amps is plenty.
Remove Existing
Once the breaker is off and you've checked it at least two if not three times, unscrew the receptacle cover, remove the receptacle, remove the wires with a screwdriver, and in this case the box. You will need to remove the conduit bracket as well.
Since these receptacles are on the same breaker as the room above, I'm removing the wire back to the junction box. I want that room and my shop separate.
I made sure the breaker for that junction box was off before disconnecting the wire. I labeled the junction box with what room it served and the circuit #.
While running new wire in the ceiling, I found two pieces of wire not connected to anything.
Preparation
I ran all new wire, from the breaker box to my receptacles. While I would have liked to reuse the baseboard heater wire, it runs into the walls for the controllers. It's best to start new.
Drill a 1/2" hole through the joists near the bottom. The wire will feed through this hole. You shouldn't surface mount wire and this was double true in my case since I was adding a ceiling too.
I knew I had two runs of wire, one for each circuit I was putting in, so I left 12" extra past the bottom of the breaker box so I'd be sure to have enough. I did the breaker box work last.
I drilled a hole through each joist, reusing existing holes if I could to get the wire from the breaker box to the first receptacle.
I ran the wire to the first receptacle. The other receptacles chain off of that one.
I ran a different wire for the dust collector receptacle. Nothing chains off of that one. It was a straight shot between two joists from the box to the receptacle and down the wall..
Conduit runs down the wall to the box locations getting the wire from the ceiling to the receptacle location. Conduit is required to protect your wire. I used just one strap midway at the wall. The end is anchored at the box. I mounted the boxes 48" above the floor, roughly equal intervals down the wall.
The box and strap are attached with a plastic anchor drilled into the CMU block.
I reused the screw and plastic anchor for one of the boxes. The anchors hammer in.
Receptacle Wiring
I was connecting a new wire from the breaker box to the first receptacle. Then I chained to the next receptacle and the next.
You can keep chaining, but since I run into a branch, I'm installing a junction box to use less wire and split my wire three ways.
For each receptacle, I'll run the incoming wire to the first receptacle, through the two gang box with a strain relief, then chain the second. With this configuration, if the first receptacle fails, the second stops working. You could wire them both parallel so one failure doesn't affect the second, but if a receptacle fails, I will be replacing it anyway. Then wire runs from the second receptacle out the two gang box, through a strain relief connection and then between/through the joists to the next receptacle.
With a grouping of wire for the neutral, I tape the wires together, then twist them with needle nose pliers before wire nutting them. It just makes it easier if they are tied together.
It's critical to make sure wires are connected properly. This will save you headache and troubleshooting later. All it takes is one loose wire for things to not work.
Instead of in series, you could wire the receptacles parallel, where the incoming power, outgoing power, and a power from each receptacle is wire nutted together, same with the ground.
I went with metal covers for the receptacles, being a shop and having exposed boxes and conduit, it just looks better compared to plastic covers.
Junction Box
A junction box allows me to split the wire three ways without doubling up on wire trying to chain receptacles. If I tried to chain the receptacles I would have to go down and up the wall with wire. With the junction box I just go down.
Make sure your connections are good. It takes just one loose wire for a receptacle to not work.
I write on the junction box cover what it serves and the circuit #, just so in the future I'll know what it is. The future homeowner will thank me!
Overhead Receptacles
The new overhead receptacles have the boxes screwed to the joist with 1.25" coarse screws. I spaced them a foot from the edge of the future work bench. I was going to put them next to each other in the center of the bench, but that would just cause me to have to lean too far over the table. With low ceilings, the receptacles aren't hard to reach. With a taller ceiling, I'd have put in a drop receptacle.
Breaker Box Work
Talk to an electrician if you are going to do work in the breaker box. It can be dangerous. I'm willing to tackle any project on my own and even I talked to an electrician.
The sub panel where I was modifying the circuits had a main breaker on the outside of the house near the electric meter. After flipping that breaker and removing the breaker box cover, the leads were checked in the sub panel before any work was done.
To remove the 240 volt 20 amp breaker the electrician pulled it back and out from the center of the box. It's got one power/block wire screwed into it.
The resulting opening provides space for the (2) single pole 20 amp breakers. The black/power wire is connected to the breaker and the white/ground and green/neutral are connected to the bank of grounds in the breaker box. If this is an existing breaker box, you'll see other wires connected here.
The new wires were run through a strain relief connector in the top of the breaker box.
The 30 amp breaker was installed in the same way, though I did have to buy a 1" strain relief/collar to fit the wire and remove a knockout in the breaker box for it.
I had 2 runs of abandoned wire. I clipped them at the ceiling where they entered no man's land.
Once complete, label the breakers on the panel label.
A breaker box has two blocks running down it that would be your two columns of breakers. Each block provides a 120 volts.
A double pole breaker connects to both blocks/columns and thus provides 240 volts.
The ground and neutral wires connect to a ground block that is also in the box.
Troubleshooting
At the conclusion of work your receptacles should work. If they don't, you should have made sure to make good connections. The connection at the receptacle or junction box is likely the culprit.
Check the voltage at the breaker box, it should be 120 volts right off the breaker.
Assuming you have power at the breaker box and power out from the breaker, check the receptacles to find which ones don't work. Then flip the breaker off. Double check it's off.
Then check the first receptacle that didn't work. If you chained them like I did and the first one works and the second doesn't, none after the second will work and you must have a bad connection at the second.
If the receptacles before the junction box work and the ones after don't, or only some of the receptacles after the junction box work, a loose connection at the junction box is likely the problem.
Make the corrections, flip the breaker on and run through the process again.
Conclusion
Adding receptacles caused me to re-think my entire shop layout, which didn't have much thought.
I love this upgrade. I'm not constantly wish for more outlets. The stationary equipment can stay plugged in, ready to use when I need it.
No comments:
Post a Comment