Ground location

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Pat75

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Electrician
I work in several different jurisdictions, most of which are on the 2017 NEC.
The question is when required to mount the exterior service safety disconnect switch...is this actually the Main now? Requiring SER to panel on other side of wall and all the grounding and bonding done outside? Thanks!
 
Pat75 said:
I work in several different jurisdictions, most of which are on the 2017 NEC.
The question is when required to mount the exterior service safety disconnect switch...is this actually the Main now? Requiring SER to panel on other side of wall and all the grounding and bonding done outside? Thanks!
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For the 2017 NEC the EM disconnect is not required. As Dave stated what the switch actually is can come down in part to the labeling. If you want the exterior switch to be the EM disconnect you can label it as such and run a 3-wire (SEU) to the interior panel which will contain the service disconnect. If the exterior disconnect is the EM and service disconnect it has to be labeled as such and a 4-wire feeder (SER) will be required.
 
Fortunately TN is still 2017.
In regard to the OP, IF the outside disconnect is ordained as the "EM", would that not mean you could do your bonding and grounding there OR at the interior service panel ?
 
Seems like if its truly an Emergency Disconnect the bond and grounding occurs inside structure. If you label the outside Emergency and do your bonding and grounding there, then its SER to the next panel.....regardless of what the outside is labeled.
 
There are two choices.
1) EMERGENCY DISCONNECT, SERVICE DISCONNECT
With this label, the main bonding jumper and the grounding electrodes are located at this disconnect. You need to install the ungrounded, grounded, and grounding conductors from the outside to the inside.

2) EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT
With this choice the neutral is used to bond the metal parts of the disconnect, but the main bonding jumper and GEC connection at at the interior service equipment. You only need to install the ungrounded and grounded conductors from the outside to the inside.
 
Thanks Don. So if I understand you correctly, with option 2 that you presented, the neutral, being used to bond the metal parts of the disconnect, would therefore need the bond screw in place to accomplish this. Correct?
 
Pat75 said:
Thanks Don. So if I understand you correctly, with option 2 that you presented, the neutral, being used to bond the metal parts of the disconnect, would therefore need the bond screw in place to accomplish this. Correct?
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That or a wire jumper.
 
don_resqcapt19 said:
There are two choices.
1) EMERGENCY DISCONNECT, SERVICE DISCONNECT
With this label, the main bonding jumper and the grounding electrodes are located at this disconnect. You need to install the ungrounded, grounded, and grounding conductors from the outside to the inside.

2) EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT
With this choice the neutral is used to bond the metal parts of the disconnect, but the main bonding jumper and GEC connection at at the interior service equipment. You only need to install the ungrounded and grounded conductors from the outside to the inside.
Click to expand...
Other than the technical issue of bonding and three or four wires.....what is the difference between the two? Does it matter to the fire department or anyone else?
 
Greg1707 said:
Other than the technical issue of bonding and three or four wires.....what is the difference between the two? Does it matter to the fire department or anyone else?
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The rule was written that way to permit work on the outside without triggering a requirement to redo the grounding connection points.
 
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