2020 NEC 250.140

B677

Member
Location
Florida
Occupation
EC
Replacing aerial to underground by installing a meter main combo outside with feed through lugs into the garage panel (just behind the block wall). The main service panel inside will now become a subpanel and the grounds and neutrals will have to be separated. The main breaker in the inside panel is a 150A and the Meter main outside will be 200A.

So the inspector says now they enforcing the following : any three wire circuits CANNOT be in a subpanel and will have to be extended into the meter main and OCPD will have to be in the Service equipment not the newly converted subpanel. I asked if we can put the dryer and range on GFCI instead and inspector said no because the grounded conductor is not insulated ? He did say to show him in the code where it can be done and he will pass it along to everyone else (This is a great inspector to work with - always helpful)

Thing is that the Dryer has not ground and has red black and white INSULATED conductors - the circuit is not being modified or extended (unless we have to extend to outdoor meter main). The Range is SE cable and does currently originate from the service equipment (so I see where 250.140(4) might kick in -the uninsulated grounded conductor might touch metal that connected to ground somewhere upstream and create a parallel path?) . But the Dryer should be fine to leave in the main panel correct?

The extension to the meter main / would likely be more than 5' and that IMO would trigger upgrade to GFCI and possibly having to upgrade to 4 wire. The reason we are trying to avoid extending to the meter main is that it's only an 8 space (due to feed through lugs). Generator Interlock breaker, SPD, Dryer and Range will use up all the spaces and we still need space for a future pool panel breaker.

thanks for any insights
 
Regroup and figure out how you can make the outside main an Emergency Disconnect per 230.85
 
Replacing aerial to underground by installing a meter main combo outside with feed through lugs into the garage panel (just behind the block wall). The main service panel inside will now become a subpanel and the grounds and neutrals will have to be separated. The main breaker in the inside panel is a 150A and the Meter main outside will be 200A.

So the inspector says now they enforcing the following : any three wire circuits CANNOT be in a subpanel and will have to be extended into the meter main and OCPD will have to be in the Service equipment not the newly converted subpanel. I asked if we can put the dryer and range on GFCI instead and inspector said no because the grounded conductor is not insulated ? He did say to show him in the code where it can be done and he will pass it along to everyone else (This is a great inspector to work with - always helpful)

Thing is that the Dryer has not ground and has red black and white INSULATED conductors - the circuit is not being modified or extended (unless we have to extend to outdoor meter main). The Range is SE cable and does currently originate from the service equipment (so I see where 250.140(4) might kick in -the uninsulated grounded conductor might touch metal that connected to ground somewhere upstream and create a parallel path?) . But the Dryer should be fine to leave in the main panel correct?

The extension to the meter main / would likely be more than 5' and that IMO would trigger upgrade to GFCI and possibly having to upgrade to 4 wire. The reason we are trying to avoid extending to the meter main is that it's only an 8 space (due to feed through lugs). Generator Interlock breaker, SPD, Dryer and Range will use up all the spaces and we still need space for a future pool panel breaker.

thanks for any insights
As Roger says, this is covered by 230.85. This type of installation is the very reason list item (3) in 230.85 exists.
EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT
With that label you only run three conductors to the inside panel and the inside panel remains the service disconnect. Nothing has to change with the inside panel, however some AHJs have refused to accept this part of the rule in 230.85.
 
As Roger says, this is covered by 230.85. This type of installation is the very reason list item (3) in 230.85 exists.

With that label you only run three conductors to the inside panel and the inside panel remains the service disconnect. Nothing has to change with the inside panel, however some AHJs have refused to accept this part of the rule in 230.85.
Anything to worry about grouping disconnects as mentioned above ? Can I have a 200 service disconnect outside, and a 150 disconnect on the inside panel or even a 200 outside a 200 inside. I know it was OK on the 2017 code.

I have a pack of the not service equipment, stickers, just for this case I haven’t had to do one.

The three wire issue came up one other time, and the Inspector believe it or not. Had me tape up the entire Braid with white tape
 
Anything to worry about grouping disconnects as mentioned above ? Can I have a 200 service disconnect outside, and a 150 disconnect on the inside panel or even a 200 outside a 200 inside. I know it was OK on the 2017 code.

I have a pack of the not service equipment, stickers, just for this case I haven’t had to do one.

The three wire issue came up one other time, and the Inspector believe it or not. Had me tape up the entire Braid with white tape
You only have one service disconnect. It is either the 200 amp outside one or the 150 amp inside one, based on what labl from 230.85 that you apply to the outside one.

To make the inside breaker the service disconnect, the outside disconnect must be marked exactly as shown below.
"EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT"
 
I'm interested in the technical side of this as well:

e.g. 240V only circuit (like AC only) VS 240V/120V combo with EGC

Are these treated the same ? Why can/can't they be in a subpanel ? On say a dryer with L1/L2/N but no EGC - could done use a GFCI in a subpanel instead of moving the circuit to the service panel ?
 
I'm interested in the technical side of this as well:

e.g. 240V only circuit (like AC only) VS 240V/120V combo with EGC

Are these treated the same ? Why can/can't they be in a subpanel ? On say a dryer with L1/L2/N but no EGC - could done use a GFCI in a subpanel instead of moving the circuit to the service panel ?
One issue with the 3-wire cable in the sub-panel is that the bare conductor is carrying current under normal conditions. Even if it terminates on the neutral bus any contact that bare conductor makes with the enclosure or a bare EGC will put neutral current on the EGC's and the panel enclosure essentially bonding the neutral in the sub-panel.
 
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