Marking out panel for conduit

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liquidtite

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Witch is more accurate way to mark out conduit entering top of back box.

I usually first take a piece of deep strut witch the conduit will be supported on

befor entering panel .

and make my back line with the deep strut , then I'll take a connector put it up to the back line

and the get my halfway mark of the connector .


is their a chart that gives you the half way mark of the diff sizes of conduit ?

is this the method you guys use or do you use the conduit its self ?
 
If you use strut to mark the back edge of your KO's with 2" and smaller EMT the tubing will be crooked because the EMT diameter is smaller than the actual KO. You would need to adjust the line about 1/16"-1/8" of an inch if you want the vertical conduit to enter plumb. I usually measure the actual cutter from the KO set and use that dimension to layout the KO's and adjust for the smaller EMT.
 
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As Rob says depends on what kind of raceway you are using. EMT is smaller then the KO. RMC/IMC is approximately same size as the KO.
 
liquidtite said:
So for emt using the center point on the cutter of the knock out kit is most accurate .
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Depends if you want to lay a piece of strut across the top of the panel and make a line for the back of all of the KO's it's not going to work correctly if you are using 2" of smaller EMT. If you make the correction to that straight line then you do not need to use the center of the KO.
 
liquidtite said:
So would you move your back line up an 1/8 " or back for 2" or smaller
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Yes, so if your strut were 1.5" and you made a line across 1.5" from the back of the panel you would adjust the line to be say 1/8" less or 1.375" from the panel back. This would allow the EMT to be plumb and the larger KO hole to be slightly closer to the back of the panel. If using 2.5" or larger EMT or RMC just run the line across the strut and that's the back of your KO. :thumbsup:
 
Make your line, then measure the diameter of the raceway, half of that (the radius) is the center point of the hole.

1/2 EMT is approximately 3/4" diameter, the center of your KO should be 3/8 of an inch from the line you made with the strut.
 
liquidtite said:
So for emt using the center point on the cutter of the knock out kit is most accurate .
Click to expand...

For a hole cutter or hole saw IMO yes.

For punch sets I disagree with that because you cannot see this center mark with the punch die in the way and the center mark already drilled out.

If I really want to do it perfect I use a square and a pencil to make a cross on the center mark and line the punch die indicating marks* up with the cross lines.


(*If you look carefully at the side of a punch die you will find four small lines embossed on the edge of the die 90 degrees apart to line up the center. The marks are faint, often I hit them with my sharpie to make them stand out.)
 
I decided to check my tool box near me to see if I had a punch inside to show here. Even better I found a 2" die that still has my painters tape and sharpie mark pointing out the marks I was talking about.

They are small and faint but I have found them on most if not all punches.
 

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When doing multiple KO's I like to draw a box for each hole on blue masking tape, find the center and then line up the CUTTER side of the KO tool with the lines. IMO this is the most accurate method. Here is 68 KO's, 34 KO's on each side for this large pull box. You can see the cutter in photo #2.

Box KO3.jpg
Box KO1.jpg
 
infinity said:
When doing multiple KO's I like to draw a box for each hole on blue masking tape, find the center and then line up the CUTTER side of the KO tool with the lines. IMO this is the most accurate method.
Click to expand...

I would say the results of your box method or using the factory punch center marks would be indistinguishable. Either is going to be on the money. :)

Your method requires drawing more lines but is likely easier to see in low light.:)
 
iwire said:
I would say the results of your box method or using the factory punch center marks would be indistinguishable. Either is going to be on the money. :)

Your method requires drawing more lines but is likely easier to see in low light.:)
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It depends how good your eyes are and how good the markings are on your KO set. :D
 
infinity said:
It depends how good your eyes are and how good the markings are on your KO set. :D
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Exactly. :D

I was brought into using punches for everything.

We would drill a 3/8" hole, punch that to 7/8" and then if needed punch that to 3/4" or larger. I moved into hole saws for 1/2" 3/4" and 1" but I have to step up my game and move to hole cutters.
 
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