Transformer Ground Lugs
- Thread starter Turk1957
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Lugs for EGCs would be sized according to the size of the associated EGC, which is sized according to table 250.122. Keep in mind a wire type EGC might not be required at all (for instance if using rigid metal conduit). You will need one or more incoming EGCs (sized per table 250.122 according to the OCPD rating of the supply) and one or more for the secondary EGC sized according to its OCPD rating.
Table 250.66 defines the size of conductors for GEC. Your lugs would need to match up with them.
The number of wire type EGCs (if used) depends on how many raceways are used. You need a full size EGC in each raceway if you are doing it that way.
The question is coming from Square D for a 2500kVA Transformer Bill of Material... They are asking me to verify Ground Lug size and quantity required..
- Location
- Illinois
- Occupation
- retired electrician
Yes, they need to know what size YOUR installation will require.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
You will need to figure it out and tell them no one here knows what you will do. Maybe instead of lugs they can supply a ground bus with drilled holed and you can use compression terminals.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Yes they will provide what the designer asks for. They are not being paid to do the design.
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