A "terminal bar" used for the termination of equipment grounding conductors is shown here on the right side of this cabinet.
This cabinet encloses a panelboard, and is usually called a "subpanel," and the panelboard's grounded conductor (neutral concuctor with the white identification) is "isolated" or "floating from the metal cabinet, or so called "can" and the EGC terminal is "BONDED" to the can.
This is a "terminal bar" and this is where the EGC's are to be secured under each terminal, some of which may only allow two of the same size per terminal.
The panelboard cover will include this information.
408.20 Grounding of Panelboards.
Panelboard cabinets and panelboard frames, if of metal, shall be in physical contact with each other and shall be grounded.
Where the panelboard is used with nonmetallic raceway or cable or where separate grounding conductors are provided, a terminal bar for the grounding conductors shall be secured inside the cabinet.
The terminal bar shall be bonded to the cabinet and panelboard frame, if of metal; otherwise it shall be connected to the grounding conductor that is run with the conductors feeding the panelboard.
[This message has been edited by Joe Tedesco (edited 03-31-2005).]
Joe, if someone needs to look at the cover on the panel in order to "recognize a terminal bar" and determine which is for the grounding conductors and which is for the grounded conductors do you think they should be in the panel in the first place?
Not to say the labeling is unimportant but this is some basic electrical knowledge.
Bob Badger Construction & Maintenance Electrician Massachusetts
Re: How to Recognize a "Terminal Bar"#85261 06/14/0307:19 AM06/14/0307:19 AM
Exactly, I posted this message and the images from my gallery just for that reason because some people are not sure of what was meant by a "terminal bar" and with 408.20 in mind this is offered to clear up the confusion.
Too many are under the impression that the rules for boxes in 250.148 is applied in a panelboard!
Joe Tedesco, NEC Consultant
Re: How to Recognize a "Terminal Bar"#85263 06/15/0308:53 AM06/15/0308:53 AM
Thanks for the clarification, Joe. Now, all we need is more exact wording, e.g., "..one or more terminal bars for terminating all non-isolated grounding conductors shall be secured inside the cabinet." This would better represent the actual practice of using multiple terminal bars, as well as specify the apparent intent of landing ALL the non-isolated equipment grounding conductors at the terminal bar. Anyone have easy access to a panelboard cover that has specific wording that EGC's have to land on the terminal bar? Or, does the wording just specify that the bar is provided for the EGC's (with no mandatory usage implied)?
Re: How to Recognize a "Terminal Bar"#85267 06/15/0306:32 PM06/15/0306:32 PM