What do you mean by “It depends on the conductors feeding the equipment.”It depends on the conductors feeding the equipment.
Generally, only made electrodes never need larger than #6.
Sorry, I meant server racks like computer room, I have server racks that are not grounded. I want to ground the rackWhat is a "service rack"? Are you grounding or bonding? Things in TIA documents aren't typically NEC requirements.
If it is for an electrical service (e.g. NEC 230 conductors), table 250.66 or 250.102 may apply. The values are based on the size of the conductors powering the service rack.
If it is just some rack powering equipment, then table 250.122 would apply and that is based on the size overcurrent device protecting the conductors powering the service rack.
What is this ground to the rack going to accomplish? Is it going to make the equipment safer? Will it improve the function of any of the gear in the room? Is it something that gets put into specs just because everybody else does it that way?Sorry, I meant server racks like computer room, I have server racks that are not grounded. I want to ground the rack
the main question is if the length of cable is 90-100ft can I still use #6 awg ground or do I need to upsize the ground conductor to make the ground effective
this server rack has been running without a ground. They installed the branch without ground wires, so I am pulling single ground in EMTIt need not be larger than that required for the largest single circuit feeding it.
To make the equipment saferWhat is this ground to the rack going to accomplish? Is it going to make the equipment safer? Will it improve the function of any of the gear in the room? Is it something that gets put into specs just because everybody else does it that way?
There will be #6awg from busbar to the server rack,california electric code requires the green wire even in the rigid pipe
but what about the choke? bonding bushing? and pvc pipe
but the inspector told me never to have a supplemental ground rod or offer at a remote subpanel 'cause parallel paths
but what about outbuildings?
soares book on grounding
this server rack has been running without a ground. They installed the branch without ground wires, so I am pulling single ground in EMT
I don't know about any California requirements but in the rest of the world the EMT is the equipment ground and it is perfectly safe and effective. If you are wanting to add a redundant green wire you would size it based on table 250.122 and 300.3(B) would require it to be inside the same EMT as the other circuit conductors.To make the equipment safer
This is off topic can you repost in grounding and bonding?california electric code requires the green wire even in the rigid pipe
but what about the choke? bonding bushing? and pvc pipe
but the inspector told me never to have a supplemental ground rod or offer at a remote subpanel 'cause parallel paths
but what about outbuildings?
soares book on grounding
A single ground, in EMT, that is not run with the branch circuit conductors to the server rack is violation and will accomplish nothing.this server rack has been running without a ground. They installed the branch without ground wires, so I am pulling single ground in EMT
Thank you for clear explanationA single ground, in EMT, that is not run with the branch circuit conductors to the server rack is violation and will accomplish nothing.
In a ground fault, the magnetic fields of the ungrounded conductors and EGC (Green wire) cancel, keep in mind the high magnetic fields. It the EGC is seperate from the ungrounded conductors the impedance is greatly increased and little fault current returns to the source.
See section 300.5.
Pull the EGC with the circuit conductors. If the existing it uses EMT that qualifies as an EGC, but many specs require a wire type EGC.
If you are referring to a TIA standard, then I doubt that is the reason. The EGC run with the circuit will handle that.To make the equipment safer
You use #6 copper jumper from the busbar to the server racks, but What I am trying to figure out is how to bring a ground near to the server rack, if the panel is 100ft away how do I size that ground?We bond server racks, data racks, overhead cable tray and other equipment in IT rooms with a #6 copper jumper. We even bond the floor (not a raised floor) which has a metal tape under the tile.