Nema 4 hole vs 2 Hole Lugs
Nema 4 hole vs 2 Hole Lugs
(OP)
For North American electrical installations, when it comes to power conductor termination into electrical equipment such as MCCs, starting reactors, VFD, etc, I am always confused on which Nema lug to choose: Nema 2 hole pattern or Nema 4 hole pattern? This is a simple question for someone with the experience. So would someone be so kind to clarify my confusion so that I know in the future what I should specify:
- First of all, is there advantage and disadvantage of choosing a Nema 4 hole pattern lug vs a 2 hole?
- Is there any "rule of thumb" on which pattern to choice depending on equipment type, voltage rating, conductor size, etc...?
- Should I be specifying the lug termination on my electrical equipment? Ie: "Provide Nema 2 hole lug for a #2/0 Conductor." Is it worth the effort to include this detail (and keep track that it is correct)? Or should I omit this, and let the installation contractor determine and supply?
Thanks,
Majesus
- First of all, is there advantage and disadvantage of choosing a Nema 4 hole pattern lug vs a 2 hole?
- Is there any "rule of thumb" on which pattern to choice depending on equipment type, voltage rating, conductor size, etc...?
- Should I be specifying the lug termination on my electrical equipment? Ie: "Provide Nema 2 hole lug for a #2/0 Conductor." Is it worth the effort to include this detail (and keep track that it is correct)? Or should I omit this, and let the installation contractor determine and supply?
Thanks,
Majesus






RE: Nema 4 hole vs 2 Hole Lugs
2-hole lugs prevent lugs turning when tightening. Better installations use 2-hole long barrel lugs (vs. 1-hole lugs)
4-holes may be required on the busbars or spade connections.
Rafiq Bulsara
http://www.srengineersct.com
RE: Nema 4 hole vs 2 Hole Lugs
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RE: Nema 4 hole vs 2 Hole Lugs
If I have the option, I will specify 2 hole. I see it as the best option in terms of the 1,2 and 4 hole option. 2 hole prevents lugs turning when tightening. The 4 hole option seems to be an overkill and is not necessary. Why make it more complicate in terms of installation and cost if not required.
RE: Nema 4 hole vs 2 Hole Lugs
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RE: Nema 4 hole vs 2 Hole Lugs
Bill
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"Why not the best?"
Jimmy Carter
RE: Nema 4 hole vs 2 Hole Lugs