Replace Meter socket - 2020NEC

Status
Not open for further replies.
W

WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
I'm replacing a meter socket at a single family dwelling. I'm leaning towards a "meter, main" combo enclosure. This meets the emergency disconnect requirement. It's a Siemens product with a 200A circuit breaker. Using this meter/main I plan to turn the former service panel into a subpanel by separating the Neutral conductors from the equipment grounding conductors.

Reason this work is happening is that underground utility conductors are being moved to avoid a garage expansion.

Turns out to be quite a bit of electrical work, forced by the power company, XCEL.

I'd appreciate thoughts, options etc...
 
I use those a lot. It's a pretty common fix. The 200 amp with feed through lugs and 8/16 additional spaces are very useful panels combos.
 
Buck Parrish said:
I use those a lot. It's a pretty common fix. The 200 amp with feed through lugs and 8/16 additional spaces are very useful panels combos.
Click to expand...
The 8/16 panel allow me to install a surge suppressor (SP) breaker, also a code requirement. The existing panel is full, so it's more work to get a SP breaker installed there.

Any way to avoid separation of neutral and grounding conductors?
 
WSG said:
The 8/16 panel allow me to install a surge suppressor (SP) breaker, also a code requirement. The existing panel is full, so it's more work to get a SP breaker installed there.

Any way to avoid separation of neutral and grounding conductors?
Click to expand...
You can avoid separating the neutral and grounds if you use an emo disconnect that is not service equipment

230.85 Emergency Disconnects.

For one- and two-family dwelling units, all service conductors shall terminate in disconnecting means having a short-circuit current rating equal to or greater than the available fault current, installed in a readily accessible outdoor location. If more than one disconnect is provided, they shall be grouped. Each disconnect shall be one of the following:
  • (1)
    Service disconnects marked as follows:
    EMERGENCY DISCONNECT,
    SERVICE DISCONNECT
  • (2)
    Meter disconnects installed per 230.82(3) and marked as follows:
    EMERGENCY DISCONNECT,
    METER DISCONNECT,
    NOT SERVICE EQUIPMENT
  • (3)
    Other listed disconnect switches or circuit breakers on the supply side of each service disconnect that are suitable for use as service equipment and marked as follows:
    EMERGENCY DISCONNECT,
    NOT SERVICE EQUIPMENT

Markings shall comply with 110.21(B).
Click to expand...
 
It's not usually a big deal separating the neutral from the egc. We do it all the time. Depending on the panel of course. Some panels have the neutral bar connected to the housing through a buss behind the main breaker. Other panels it's as easy as just simply removing the jumper. .

Of course you'll have to install a 4 wire feeder.
 
Dennis Alwon said:
You can avoid separating the neutral and grounds if you use an emo disconnect that is not service equipment
Click to expand...
I would use the marking from item 3 and not 2, as the utilities around here will not permit any disconnect on the line side of their cash register, other than the one they require for self contained 480 volt meters.
 
don_resqcapt19 said:
I would use the marking from item 3 and not 2, as the utilities around here will not permit any disconnect on the line side of their cash register, other than the one they require for self contained 480 volt meters.
Click to expand...
Yeah I should have said use 3 if the power company doesn't allow 2. Safest to use 3
 
I'm my experience with existing service panels, the equip grounds are intermixed with the Neutrals on the same 'ground bar'. Knowing this I usually add cost for separating these conductors
 
If you install an external panel with both main and branch breakers, then I think the outside main must be the service disconnect.

You are correct that if the feeder no longer supplies the entire load of the dwelling, you loose the '83% sizing' used for service conductors. However if it does supply the full building you can still use that sizing, and in no case does the feeder need a greater ampacity than the service conductors.

Jon
 
Buck Parrish said:
It's not usually a big deal separating the neutral from the egc. We do it all the time. Depending on the panel of course. Some panels have the neutral bar connected to the housing through a buss behind the main breaker. Other panels it's as easy as just simply removing the jumper. .

Of course you'll have to install a 4 wire feeder.
Click to expand...
And relocate the GEC to the new service disconnect. This can sometimes be a real pain.

Rob G
 
Buck Parrish said:
It's not usually a big deal separating the neutral from the egc. We do it all the time. Depending on the panel of course. Some panels have the neutral bar connected to the housing through a buss behind the main breaker. Other panels it's as easy as just simply removing the jumper. .

Of course you'll have to install a 4 wire feeder.
Click to expand...
I've had similar scenarios where I had to tell our guys to separate N from G in panels where the ground and neutral bars were bonded and both bars had a mixture of N's and G's. I hated to tell them to do it but it had to be done.
 
EXISTING SERVICE
- Meter socket with underground service feed
- Main circuit breaker panel, 200A, located in basement, below meter socket. 2" PVC conduit between meter socket and circuit breaker panel. Existing panel is full with no spare breaker spaces.

WORK OPTIONS (I may be missing some and they may be out of proper sequence)
(1) meter main combo only with no branch circuit breaker spaces
- Remove and replace meter socket, land existing line and load conductors to meter socket lugs.​
- Label exterior of new meter socket according to NEC2020 230.85 (3), "EMERGENCY DISCONNET, NOT SERVICE EQUIPMENT"​
- Install 2 ground rods with #6 solid Cu conductor. Land conductor in new meter socket enclosure​

--- OR ----

(2) mater main combo with 8 circuit breaker spaces, with feed-thru lugs for 200A
- Remove and replace meter socket, land existing line and load conductors to meter socket lugs.​
- Replace conductors between meter socket and circuit breaker panel. Upsize because oUse 3/0 copper to allow reuse of 2" PVC conduit. Add in EGC, to make it a 4-wire feeder.​
- Label exterior of new meter socket according to NEC2020 230.85 (1), "EMERGENCY DISCONNET, SERVICE DISCONNECT"​
- Install 2 ground rods with #6 solid Cu conductor. Land conductor in new meter socket enclosure​
- In existing circuit breaker panel, separate equip grounding and grounded (neutral) conductors. Remove bonding connection between enclosure and Neutral bar. Possibly, isolate the neutral bar from the metallic enclosure.​
- "Extend" grounding electrode conductor (GEC) to new meter socket, service equipment. Likely, this is one conductor (#4 copper) which touches the incoming water supply pipe.​
- install surge protective device (breaker type) in new exterior 8 space panel that is part of the meter.​
​
​
I'm leaning towards OPTION 1 because of the lower cost and effort. I may or may not talk to the homeowner about these options. Of course, OPTION 2 gives some allowance for future expansion.
 
WSG said:
I'm replacing a meter socket at a single family dwelling.

Reason this work is happening is that underground utility conductors are being moved to avoid a garage expansion.

Turns out to be quite a bit of electrical work, forced by the power company, XCEL.

I'd appreciate thoughts, options etc...
Click to expand...
My thoughts are that you are doing a complete service change and may as well permit it as such and charge accordingly.
 
Status
Not open for further replies.
Top