Lets talk extension cords and power strips

[northernlights1]

not a particularly **** topic but one of interest as I am wiring up a movable 8' workbench with some power added to it. Because it is on wheels it won't have fixed power coming to it(conduit, etc). In the garage there is one 120v 20amp circuit with 12 awg wiring to each receptacle. How does 1. extension cords(length and diameter) and 2. power strips reduce the capacity/amperage of what's plugged into them? Safety concerns?

For instance most residential power strips are 14gauge 15amp. I get that it makes sense to down step everything downstream of the 20amp receptacle but a few tools are right at 15amp draw. So don't want to be popping that breaker on the strip.

 

[mm08822]

Roll your own........Put in 2-3-4 quads on the face/sides of it using 4" sq boxes, metal covers and 1/2" emt. Feed one of the boxes with 12-3 or 14-3 SO cord using a kellems grip into that box. Buy spec grade recepts.

 

[niget2002]

I've had issues with my metal saw popping the little safety switch on the metal power strip mounted to the back of my rolling bench. I only have 3 devices on that bench that need power, so I ended up just buying a heavy duty extension cord and a heavy duty 3-way plug. I leave the 3 way plug on the bench and just hook up the power cord anytime I need to use stuff on that bench.

I'm only 1 person, so I'm only ever using 1 tool at a time.

 

[dcg9381]

For instance most residential power strips are 14gauge 15amp. I get that it makes sense to down step everything downstream of the 20amp receptacle but a few tools are right at 15amp draw. So don't want to be popping that breaker on the strip.

You need 12GA 20A. They're a little hard to find.

Might search for "20A PDU" - you can find these used and not pay a fortune for them.



I like the "roll your own" suggestion also...

 

[wssix99]

For instance most residential power strips are 14gauge 15amp. I get that it makes sense to down step everything downstream of the 20amp receptacle but a few tools are right at 15amp draw. So don't want to be popping that breaker on the strip.

If you took apart most power strips, you might find that they have 16 gauge wires in them. Appliance wires are usually smaller on the final part of a run to the appliance because they aren't carrying loads of other outlets. (So the wires in the walls are thicker by code.)

As long as you are within the specs of your power strip, you are good. Issues only occur when people daisy chain things like power strips or extension cords together. (They are not designed to do that safely...)

 

[Chuckster in NJ]

Roll your own........Put in 2-3-4 quads on the face/sides of it using 4" sq boxes, metal covers and 1/2" emt. Feed one of the boxes with 12-3 or 14-3 SO cord using a kellems grip into that box. Buy spec grade recepts.

THIS^ X2 Anything else is a waste of money and you won’t be happy in the long run…… I would suggest adding a switch so you can turn off the work bench receptacles.

BTW! When someone sees the quad boxes with spec grade devices on the work bench it screams: "That dude knows his $hit!"

 

[wssix99]

For a 8' table, why not use a table top strip? Easy, gives more than a hacked solution and it easily moves over to a new use in Garage 2.0.

 

[alfredeneuman]

UL list these as "relocatable power taps"
It is to be plugged into a permanent outlet only, cannot be daisy chained or permanent attached (hence the keyhole slots on the back) so extension cords are out.

 

[mm08822]

For a 8' table, why not use a table top strip? Easy, gives more than a hacked solution and it easily moves over to a new use in Garage 2.0.

These can also load up with saw dust, grindings and get spilled on. I wouldn't use anything permanent on the tabletop that couldn't be moved.

 

[kerrynzl]

not a particularly **** topic but one of interest as I am wiring up a movable 8' workbench with some power added to it. Because it is on wheels it won't have fixed power coming to it(conduit, etc). In the garage there is one 120v 20amp circuit with 12 awg wiring to each receptacle. How does 1. extension cords(length and diameter) and 2. power strips reduce the capacity/amperage of what's plugged into them? Safety concerns?

For instance most residential power strips are 14gauge 15amp. I get that it makes sense to down step everything downstream of the 20amp receptacle but a few tools are right at 15amp draw. So don't want to be popping that breaker on the strip.

Hardwire your work bench with a H/D cable and plug using flush-boxes and dual outlets under the bench [all parallel]
And while you're at it ,make one of the outlets have a USB charger port.[for phones / head-lamps / inspection cameras etc]

Then install a RCD circuit breaker in your garage [you can sometimes do this at the first outlet "in the loop" with an RCD outlet]
If you swap out a wall unit for an RCD outlet , you can use the old outlet on your bench.


I had this method ^^^^ for years until I went to a larger permanent toolbox so I added more wall outlets [all RCD protected off 1 outlet]
I could plug my MIG welder into my workbench.

 

[kerrynzl]

RCD ^^^ is our terminology for "ground fault circuit interrupter" (GFCI)

 

[northernlights1]

WELL. Realistically sometime I will be rolling the workbench outside and then I need an extension cord to plug into whatever power strip option I end up with. So do I find a 12gauge extension cord to plug into the final strip(s)?

 

[aggie113]

Not sure if they are worth it for you, you can use with 15a plug adapter... I got a few APC AP7801 units from eBay for cheap. They were new but you can get used as well. They show total Amps in use and you can even go so far as to network them and they might have some port control functionality.

 

[micromind]

WELL. Realistically sometime I will be rolling the workbench outside and then I need an extension cord to plug into whatever power strip option I end up with. So do I find a 12gauge extension cord to plug into the final strip(s)?

14 will work, 12 is better, 16 is questionable.

 

[Dig Doug]

Wire your work bench like stated above
and
on the power to the bench leave a 25 ft long whip hard wired in to the boxes on the bench ( or how ever long you need to plug it into an outlet )

 

[theoldwizard1]

Roll your own........Put in 2-3-4 quads on the face/sides of it using 4" sq boxes, metal covers and 1/2" emt. Feed one of the boxes with 12-3 or 14-3 SO cord using a kellems grip into that box. Buy spec grade recepts.

SO cord is rated at 600V. SJO cord is rated at 300V. Save a few bucks !

 

[mm08822]

SO cord takes a beating.

The "J" is for junior service.....aka, lighter durability.

 

[dscheidt]

Wire your work bench like stated above
and
on the power to the bench leave a 25 ft long whip hard wired in to the boxes on the bench ( or how ever long you need to plug it into an outlet )

God, no. Do not leave a tail on it. Wire it with 4” boxes and emt. (Do not use handy boxes.). But instead of a tail of cable that will always be in the way, install an inlet (it takes the female end of an extension cord). Then you can use whatever cord is the right length, and if you want to use it without power, there’s nothing to trip over.

 

[N_Jay]

I think you have misunderstanding about ampacity of an extension cord or strip.

The rating is whit CAN handle safely.

If a tool draws 17vamps, it does not care. It will still draw 17 amps on a 15 amp cord, just not with normal safety margins.

 

[N_Jay]

I would put in a 240 20A circuit, the set the bench up to split out the two sides.
A short whip will work for normal, and get a 12G 249 extension cord for when yiu roll it out.
Using a standard 4 prong twistlock will make it generator ready.

 

[dave*99]

I would put in a 240 20A circuit, the set the bench up to split out the two sides.
A short whip will work for normal, and get a 12G 249 extension cord for when yiu roll it out.
Using a standard 4 prong twistlock will make it generator ready.

That arrangement will take some extra effort to work in the OP's garage.

In the garage there is one 120v 20amp circuit with 12 awg wiring to each receptacle.

 

[mm08822]

God, no. Do not leave a tail on it. Wire it with 4” boxes and emt. (Do not use handy boxes.). But instead of a tail of cable that will always be in the way, install an inlet (it takes the female end of an extension cord). Then you can use whatever cord is the right length, and if you want to use it without power, there’s nothing to trip over.

I wouldn't call that absurd at all. Either way works. A simple hanger on the side of the bench to coil the cord works. Never need to search for a cord.

Whatever works best for the OP's situation/preference.

 

[Stuart in MN]

These can also load up with saw dust, grindings and get spilled on. I wouldn't use anything permanent on the tabletop that couldn't be moved.

A power strip (or individual receptacles for that matter) can be mounted under the bench top facing down, so dirt or debris won't fall into them.

One of my workbenches has a double receptacle in a junction box, mounted under the bench top, with a SJO cable so it can be plugged into the wall. It was decades old when I acquired it decades ago so I have no idea how old it is, probably 50 years or more. Still works just fine.

 

[northernlights1]

I would put in a 240 20A circuit, the set the bench up to split out the two sides.
A short whip will work for normal, and get a 12G 249 extension cord for when yiu roll it out.
Using a standard 4 prong twistlock will make it generator ready.

That arrangement will take some extra effort to work in the OP's garage.

Well, actually, in an adjacent storage room there is a 240 20A circuit receptacle that I could plug into, it just makes the extension cord longer and a little unwieldy. So probably will stick with TWO circuits. A power strip I can plug into an extension cord for one circuit. and then the hard wired bench I will plug into the other circuit in the main garage. So if I am running two high amperage tools at same time, I can split the load.

 

[northernlights1]

Also, looking for the hardwired circuit to use flex emt and properly connect into each 4" metal box. If each run of the flex is under 6 feet and it is properly bonded to the two or three boxes I am putting in the workbench would it be a problem (other than more work) to pig tail the ground in each box or do is that overkill and just need to pigtail the first box to ground?

 

[dave*99]

That arrangement will take some extra effort to work in the OP's garage.

Well, actually, in an adjacent storage room there is a 240 20A circuit receptacle that I could plug into, it just makes the extension cord longer and a little unwieldy. So probably will stick with TWO circuits. A power strip I can plug into an extension cord for one circuit. and then the hard wired bench I will plug into the other circuit in the main garage. So if I am running two high amperage tools at same time, I can split the load.

Is it a 3 wire plus ground 120/240 circuit? You need a neutral.

 

[Shiftless]

God, no. Do not leave a tail on it. Wire it with 4” boxes and emt. (Do not use handy boxes.). But instead of a tail of cable that will always be in the way, install an inlet (it takes the female end of an extension cord). Then you can use whatever cord is the right length, and if you want to use it without power, there’s nothing to trip over.

Similar to this advice, I recently modified my vintage Craftsman table saw. When I inherited it from my FIL, it had an 8 foot long cord attached to a switch box he mounted to the metal frame of the saw. I built a wooden rolling stand so I could move the saw outside to use it. So I always hooked it up to an extension cord. That 8 foot cord was a bit of a pain to wrap up and unwrap so I shortened it to one foot. I use an extension cord anyway.

So your rolling workbench could have a 1 foot long cord dangling down to expedite connection to an extension cord. You could probably piece that together with stuff you had laying around instead of buying an inlet connection, (But honestly, an inlet mounted in a 4x4 box with half inch EMT and a few well done bends would look way more business like and give you points in the GJ status ranking )

 

[pembol]

You definitely need to install a sub station in your garage, then a 48kV transmission line to the work bench, with a step-down transformer to 480V three phase. This is Garage Journal after all.

Seriously, don't over think this - buy a 20A power strip from a reputable brand with the cord length you need. It will be good for the rated 20A and you are done.

 

[Shiftless]

This is Garage Journal after all.

Yeah…
What if you want to have a welding competition with 20 of your buddies who bring their rigs over, plug them in and all use them simultaneously?

 

[northernlights1]

You definitely need to install a sub station in your garage, then a 48kV transmission line to the work bench, with a step-down transformer to 480V three phase. This is Garage Journal after all.

Seriously, don't over think this - buy a 20A power strip from a reputable brand with the cord length you need. It will be good for the rated 20A and you are done.

I will be sending apocalyptic and biblical amounts of power through this circuit. So the 480V sounds like the way to go as a start. My local electric co is a little reluctant right now to swing a 48kV line over to the house but I am confident they will come around...

 

[northernlights1]

Also, looking for the hardwired circuit to use flex emt and properly connect into each 4" metal box. If each run of the flex is under 6 feet and it is properly bonded to the two or three boxes I am putting in the workbench would it be a problem (other than more work) to pig tail the ground in each box or do is that overkill and just need to pigtail the first box to ground?

Didn't want this question to get lost in the fun...

 

[Stuart in MN]

Didn't want this question to get lost in the fun...

This is for wiring to outlets on the bench itself? If so, it's a portable device that doesn't fall under NEC requirements. in any case, you can run a separate ground wire or use the flex for grounding, as long as the receptacle in each box has a ground connection to its respective box.

 

[northernlights1]

This is for wiring to outlets on the bench itself? If so, it's a portable device that doesn't fall under NEC requirements. in any case, you can run a separate ground wire or use the flex for grounding, as long as the receptacle in each box has a ground connection to its respective box.

correct. for the bench. Just wondering if it's overkill to run a ground wire to each box since the boxes will all be bonded together through the flex EMT and the lead box where I will put a power inlet plug will be bonded to the incoming ground...

 

[dave*99]

correct. for the bench. Just wondering if it's overkill to run a ground wire to each box since the boxes will all be bonded together through the flex EMT and the lead box where I will put a power inlet plug will be bonded to the incoming ground...

What type conductors do you plan to put in the FMC? Have you considered using MC cable?

 

[northernlights1]

Only have a couple of 3 feet runs. Planning on just THHN 12 gauge x3. I thought about MC but it should be a simple pull for those short of distances. Why do you ask?

 

[theoldwizard1]

SO cord takes a beating.

The "J" is for junior service.....aka, lighter durability.

Well 600V insulation is a lot thicker than 300V ! SJO is plenty durable.

 

[Stuart in MN]

correct. for the bench. Just wondering if it's overkill to run a ground wire to each box since the boxes will all be bonded together through the flex EMT and the lead box where I will put a power inlet plug will be bonded to the incoming ground...

It's really up to you. Personally I like overkill too, but just using the EMT is adequate.

 

[nadogail]

IMHO, 12 Gauge 3 conductor extension cords with Hubble Plugs, I also like two commercial grade duplex receptacles in 4 square metal boxes.

 

[northernlights1]

Okay got all the boxes and conduit in. Time to pull wire and wire it all. The 4x4 boxes are 2” deep but look to be kind of full. I know most are big fans of pigtailing. But I have spec grade “industrial” grade receptacles. How a bought just feeding through the hots through the outlets and pigtailing the neutrals. (Let the debate begin…)

 

[mm08822]

Okay got all the boxes and conduit in. Time to pull wire and wire it all. The 4x4 boxes are 2” deep but look to be kind of full. I know most are big fans of pigtailing. But I have spec grade “industrial” grade receptacles. How a bought just feeding through the hots through the outlets and pigtailing the neutrals. (Let the debate begin…)

It will be fine.......finish it!