knocking out knockouts

[jxofaltrds]

Yes they're listed for bonding metal raceways and enclosures.

Thanxs Rob

 

[LarryFine]

Are they 'rated' for bonding/grounding? I mean when used with metal conduit will they make a continuous path for faults?

As stated above, yes. When used with PVC conduit and/or boxes, it doesn't matter.

I have used them with PVC and will continue, 'until acted upon by an outside force.'

 

[hurk27]

I carry a few small, 1/2" sharp wood chisel's for the tuff ones, it doesn't take much to break the edge of them but I just keep sharping them, or a sharpened small screw driver.

 

[Mr. Wizard]

I carry a few small, 1/2" sharp wood chisel's for the tuff ones, it doesn't take much to break the edge of them but I just keep sharping them, or a sharpened small screw driver.

Do you use the chisel to break the spot weld on the KO's?

 

[hurk27]

Do you use the chisel to break the spot weld on the KO's?

There not really spot welds, just un-cut from the stamping process, but yes, I use them after knocking the ring out just a little, then use the chisel to cut it the rest of the way.

 

[quogueelectric]

I always cut the middle of the size I need with dykes and fatigue the metal for the small uncut piece. If it starts to move the other pieces I use the dykes to nip out the metal holding the ring in as many cuts as it takes. I really like using the knockout idea though.........

 

[e57]

I used to know a guy who used these...

I do something simular - I get the middle one out - then cut through the rings to make it easier to twist out. But I use these:

 

[K8MHZ]

The official method

The official method

From NEMA

http://www.nema.org/stds/eng-bulletins/upload/Bull_55_09_09_04.pdf

 

[K8MHZ]

A better document with the official method:

http://docs.google.com/gview?a=v&q=...&gl=us&sig=AFQjCNFTNp0PLsK02wOF_uACwTZu7pkMrw

 

[LarryFine]

I used to know a guy who used these...

Hey, a chassis nibbling tool. I haven't seen one of those in years.

 

[shermansfather]

For enclosures already mounted where access is limited, From the inside I run 1 (or 2 about 1 inch apart) #12-#14 self drilling sheet metal screw(s) strategically placed in the innermost ko. A sharp blow at an acute angle usually does it.

 

[e57]

For enclosures already mounted where access is limited, From the inside I run 1 (or 2 about 1 inch apart) #12-#14 self drilling sheet metal screw(s) strategically placed in the innermost ko. A sharp blow at an acute angle usually does it.

I do something simular for KO's inside 4Ss inside walls that I want to fish to. Take a self-drilling rock screw, and use a guided screw tip braced against my linemans. Once the screw is in, pull in with a twist of the wrist to pull the KO in and out. (I really don't know why they are called knock outs - if they knock 'in'.... :roll

 

[220/221]

Anyone have a good trick or technique on how to easily knockout concentric or eccentric KO's without taking more rings out than you want?

It's situational, depending on the design of the KO's, what kind of acces you have and how sharp/dull the press was the day of manufacture.

I know you are not using reducing washers with PVC, as they are not permitted to be used with PVC.

This cannot be true. It's illogical and all code is based on logic.....right :grin:

 

[Power Tech]

I have use the self tapper in the KO, clipped the rings, used the punch and still use a reducing washer if I go through a concentric. I really wish they would not put them in.

I have also used a 4s or 5s plate, punched a hole and screwed it down.

 

[vinster888]

kleins and a screwdriver for me. tap the one i want at the cut spots to make gaps and then use screwdriver as chisel. usually one whack per tab sometimes two. there was a time about ten years ago i was busting out the whole thing but the manufacturing processes have changed and life is beautiful again. :grin:

 

[big john]

If the enclosure is small enough, I'll just put a C-clamp in there and tighten it right on the edge of the ring I want to bang out. Start wailing away with kleins and screwdriver while the clamp holds the other rings in place (really, really stubborn ones might take two clamps).

-John