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Emergency service disconnect grounding/bond question

jeepxj

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Upgrading to a 320/400 service. The utility provides the can with dual lugs so I can run 2 main panels. Code states I need emergency disconnects outside now which I don't have currently.

The left path is easy. isolate the neutral downstream from the generac ATS. pull the bond screw from the main 200a panel and split the grounds off.

the right path will have its own 100a emergency disconnect. https://www.ecodirect.com/Square-D-DU323RB-100A-240VAC-Safety-Switch-p/square-d-du323rb.htm
Am I overthinking this? should I treat that 100a disconnect the same way as I do the generac ats? isolate down stream.


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jeepxj

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thinking about this more I can just use a panel like this for the solar side. eliminating the separate 100a disconnect. ill just need to move the solar power panel outside.

with
 
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jeepxj

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problem solved. if it wasn't what is the answer on that knife switch?
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wyliesdiesels

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Neutral is bonded in first means of disconnect ALWAYS.

this means the house main on the left after the ATS then becomes a sub. Neutral bus needs to be isolated, bonding screw removed, all EGCs moved over to new ground bar. Neutrals need to only be on neutral bar. The generac ATS is your new main.

this may be easier said than done depending on brand and model of panel

Why are you derating the right disconnect/200a main panel? due to the solar? you would bond the neutral in this panel and every panel after that becomes a sub which means it needs to have an isolated neutral

keep in mind all GECs and metal piping bonds need to be moved over to the ATS and 200a house/solar main...
 
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jeepxj

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Neutral is bonded in first means of disconnect ALWAYS.
so if i had a knife switch there like i first thought it would be bonded there, then 4 wire in the panel itself. alrighty then i was over thinking it.

this means the house main on the left after the ATS then becomes a sub. Neutral bus needs to be isolated, bonding screw removed, all EGCs moved over to new ground bar. Neutrals need to only be on neutral bar. The generac ATS is your new main.
Yup thats easy enough for my pea brain to understand.

this may be easier said than done depending on brand and model of panel

Why are you derating the right disconnect/200a main panel? due to the solar? you would bond the neutral in this panel and every panel after that becomes a sub which means it needs to have an isolated neutral
120% bus rating for solar means I can do a 100 or 125 panel there. i'm at 21kw for solar coming in on 6 circuits using microinverters.

yup that i can manage. and thankfully those two panels below are already subs so this is already split up correctly.

keep in mind all GECs and metal piping bonds need to be moved over to the ATS and 200a house/solar main...
right now its got the usual 2 ground rods coming into the 200a main panel. I would move the ground rod #6(im pretty sure it a #6) to come into the ATS. then 4 wire it to the main panel. but now that raises a question; do I take the new solar 100a panel and just bond it over to the ats? i gotta do a wire diagram anyways over the weekend to flush it out.
thanks
 
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jeepxj

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the GECs and metal plumbing bonds need to connect to all main panels. so somehow you have to jumper them over.

lemme just change my grounding spool to 500' on the parts list. JK

shouldn't be a problem. they're all right in the same 20' of each other within the mechanical/electrical area. am i allowed to jump from main ATS to solar 100a panel? or is that a go direct from plumbing to each panel.
 

dcg9381

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I have a similar setup, not to get off topic on the grounding, one thing I had to "redesign" for was a generator option for the out-buildings (I've got solar on mine too). Those building have manual generator backup (from a 2nd generator). It would have been easier if I designed for that up front... Dunno if covering them with power backup is important to you or not.
 
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jeepxj

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I have a similar setup, not to get off topic on the grounding, one thing I had to "redesign" for was a generator option for the out-buildings (I've got solar on mine too). Those building have manual generator backup (from a 2nd generator). It would have been easier if I designed for that up front... Dunno if covering them with power backup is important to you or not.

the house main 200a and sub 100a are literally next to each other in the basement. if I need to move a circuit from sub to main for generator power its a "20 minute" project.

the garage sub panel is in my attached garage and covered the pool pump/EV charger/garage AC/extra outlets.

my long term plan is to put the outdoor EV charger to the main panel when the time comes. her having juice is more important than me. I can survive on 120v charging
 

u2slow

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I think i would pay the extra for the 400A meter-main. No existing disconnects to move outside, etc.
 
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jeepxj

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Did you check? Ours offers 200, 320, 400A service. Had to get to the engineers to get that info.

they dont do meter mains. they only do meter cans. i literally have to go pick it up from their location. they offer 320a service which is really 400a from my understanding. either way 320 is plenty for the load calc and the solar system.

in the joys of the modern world getting 320a cans from them is sporadic at best.
 

mike93lx

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they dont do meter mains. they only do meter cans. i literally have to go pick it up from their location. they offer 320a service which is really 400a from my understanding. either way 320 is plenty for the load calc and the solar system.

in the joys of the modern world getting 320a cans from them is sporadic at best.
You have to pick it up...but what if it gets misplaced and your electrician uses something else...
 

sparky 1971

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I think i would pay the extra for the 400A meter-main. No existing disconnects to move outside, etc.
If one can be found somewhere. I have one back ordered, all the supply house will tell me is "sometime next year", When I ordered mine, they had 180 ordered and I was the 84th person to get my name on one. I have a friend that has one ordered from another supply house and they told him at least six months. In the mean time, there is a local mechanic that has a main that trips since he installed AC in his shop, now that AC season is over, he should be ok for awhile. (both meter mains are for the same job, when one of us gets one in, the other order is going to get cancelled.)
 
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jeepxj

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If one can be found somewhere. I have one back ordered, all the supply house will tell me is "sometime next year", When I ordered mine, they had 180 ordered and I was the 84th person to get my name on one. I have a friend that has one ordered from another supply house and they told him at least six months. In the mean time, there is a local mechanic that has a main that trips since he installed AC in his shop, now that AC season is over, he should be ok for awhile. (both meter mains are for the same job, when one of us gets one in, the other order is going to get cancelled.)

meter main or just a meter can?
 
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sparky 1971

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meter main or just a meter can?
Meter main. Meter cans are a dime a dozen since the 2020 went into effect since residential applications now require an outdoor disconnect. The one I need is for a single phase commercial application, but still needs to be a meter main per the customer. He thinks 3R disconnects will look ugly and the panels are far enough away from were the POCO is willing to install the service that I can't just go from the meter to the panels.
 
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jeepxj

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Meter main. Meter cans are a dime a dozen since the 2020 went into effect since residential applications now require an outdoor disconnect. The one I need is for a single phase commercial application, but still needs to be a meter main per the customer. He thinks 3R disconnects will look ugly and the panels are far enough away from were the POCO is willing to install the service that I can't just go from the meter to the panels.

yea i can see that. why do an extra box if you dont need to. i feel kinda lucky to be putting the ATS and solar panel on the wall.

1667604356518.png

the worlds lowest meter that got approved somehow.
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plan is to bring the service in on the far right side of the above photo. ATS will be on that right wall as well. the main wall in front will get the 100a solar sub panel. plus room for whatever the future brings.


the next nightmare on this project; getting it all to the wall. 360 porch only looks good. makes for a real ***** to wire things.
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wyliesdiesels

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they dont do meter mains. they only do meter cans. i literally have to go pick it up from their location. they offer 320a service which is really 400a from my understanding. either way 320 is plenty for the load calc and the solar system.

in the joys of the modern world getting 320a cans from them is sporadic at best.
Yes 400a is 320a continuous. With my PoCo If you want more than 320a continuous then you have to put in a CT cabinet and meter...
 
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jeepxj

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Yes 400a is 320a continuous. With my PoCo If you want more than 320a continuous then you have to put in a CT cabinet and meter...

its interesting in the ol pdf of all the poco rules.

anything over 200a is ct*******


seemingly pages later

******** unless its a 120/240 res 320 install.
 

HamAndEggs

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Is anyone actually using more than 200a? 200a is a hell of a lot of current

I've never used above 54a since adding power monitoring, and I use a lot of power
 

wyliesdiesels

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Question, I have a gas pipe that is not bonded

Should it be?
Yes. All metal plumbing needs to be bonded. Its to prevent it from becoming energized. The bonding allows the breaker of the offending circuit to open and clear the fault current.

Ive seen what happens when plumbing isnt bonded.... have a i got a story for you...

Had a LL call years ago about tenants getting shocked when they touched the washer or a metal hose bib at one of her properties...

Took me a whole day of searching and then another to nail it down.

First thing i noticed was the water line wasnt bonded. When i bonded it to the meter main right above it, I got an arc and a breaker tripped (it was a shitsco panel).

So, then I knew the plumbing was energized but had to find where. This was a single family house that had been added onto and split into 2 units. (Oh boy; there was some other really questionable wiring like cordage running through the space between first and second floor to feed the detached garage sub-panel via overhead drop :shocking: , garage subpanel was bonded despite having 4-wires, dryer receptacle was installed out in the weather, was 4-wire but connected as 3-wire etc)

So through my searching i discovered the gas stove and refrigerator on the addition unit, were electrified also.... this started to get interesting.... finally i discovered that the ground terminal on the receptacle for the fridge and stove was energized.

Pulled the receptacle out of the j box but found nothing suspect.

Righ then i knew someone had ran an NM staple through the NM at some point in the wall.

But the EGC at the panel for this circuit was connected to the neutral bar..... :headscratSo that told me there was a splice somewhere and the EGC lost its connection at some point.

This particular circuit actually fed stuff on both units so would be a nightmare to find...

So off to demo some sheetrock to search. I didnt want to be responsible for the drywall so the LL had her handyman come over to start ripping sheetrock out.

We tore quit a bit out but i couldnt find the staple.

LL didnt want to keep going so i just disconnected the EGC from the receptacle, told her to plug the stove and fridge in elsewhere, dont use the receptacle and that she would need to have me or someone come back to find the issue.

This was a fairly large 2 story house on one side and single story on the other for the second unit.

Wouldve been a ***** to find the problem and with active tenants living in the unit im guessing the LL never bothered to dig further...
 

mike93lx

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Is anyone actually using more than 200a? 200a is a hell of a lot of current

I've never used above 54a since adding power monitoring, and I use a lot of power
If all three of my a/c's kicked on, while the pool heater was running, with something cooking and the dryer running, I should be around 150a, plus whatever the rest of the house pulls, so 170ish total?

I think to get near 200, most people would have to be running a bunch of stuff plus on demand electric DHW.
 
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jeepxj

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Is anyone actually using more than 200a? 200a is a hell of a lot of current

I've never used above 54a since adding power monitoring, and I use a lot of power
Screen Shot 2022-11-04 at 10.18.17 PM.pngScreen Shot 2022-11-04 at 10.18.06 PM.png

In no particular order:

i have 4 ac units, electric stove, electric dryer, EV 60a, pool pump.

load calc puts me around 220-230 IIRC. i gotta dig it up from last time.

even that aside; im putting 90a of solar onto a 200a main panel. 120% rule aint enough for it.
 
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jeepxj

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If all three of my a/c's kicked on, while the pool heater was running, with something cooking and the dryer running, I should be around 150a, plus whatever the rest of the house pulls, so 170ish total?

I think to get near 200, most people would have to be running a bunch of stuff plus on demand electric DHW.

with one EV its 48a. 2 will be 96A by themselves. that leaves 200a left for the house. which i think is why 320a makes perfect sense.
 

Max

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with one EV its 48a. 2 will be 96A by themselves. that leaves 200a left for the house. which i think is why 320a makes perfect sense.
It’s your place, so you do what you want. 👍. But 320 to support two EVs seems like overkill - AC load is low at night, pool shouldn’t be running, etc. It should be trivial to stagger the EVs so they don’t overlap either.

I get that due to the solar you need 320 A, but I don’t think as a general rule someone with two EVs needs 320…
 
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jeepxj

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It’s your place, so you do what you want. 👍. But 320 to support two EVs seems like overkill - AC load is low at night, pool shouldn’t be running, etc. It should be trivial to stagger the EVs so they don’t overlap either.

I get that due to the solar you need 320 A, but I don’t think as a general rule someone with two EVs needs 320…
i agree on all of that. hell you can readily get 2 EV chargers to work together and only pull 48a total.

generally speaking no; 2 EVs wont require upgrading to 320. there are a lot of options before you get to that path. my load calc says 229A with just 1 EV charger. so even if my solar was under the 120% bus rule i'd still be over on load calc and forced to upgrade anyways.
 
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