NEC Tables 250.66 and 250.122

[NEC User]

I don't understand grounding electrodes and NEC Table 250.66. Are ground rods sized per Table 250.66? I thought ground rods were sized per length, diameter, and plating thickness which are not indicated in Table 250.66.

My understanding is ground wires are sized per NEC 250.122 to ground equipment back to the load center which is then grounded. Where does Table 250.66 come into play?

 

[NEC User]

how do i delete my post? i found a similar thread.

 

[pete m.]

Table 250.66 is for sizing Grounding Electrode Conductors (among other things).

250.52 lists the Grounding Electrodes.

Table 250.122 is used for sizing Equipment Grounding Conductors.

Take a look in Article 100 at the definitions for further clarification on the terms above that are in bold.

Pete

 

[roger]

I don't understand grounding electrodes and NEC Table 250.66. Are ground rods sized per Table 250.66? I thought ground rods were sized per length, diameter, and plating thickness which are not indicated in Table 250.66.

Read all of 250.66 not just the Table

My understanding is ground wires are sized per NEC 250.122 to ground equipment back to the load center which is then grounded. Where does Table 250.66 come into play?

250.66 and 250.122 are for two completely different animals. The Grounding Electrode System is for earthing whereas Equipment Grounding is for bonding normally non?current-carrying conductive materials enclosing electrical conductors or equipment for clearing faults. Read 250.4


Roger