T,
Please see my attachment below (or above), regarding my feed thru option. Thanks!
Please Review My Project and Service Calcs
- Thread starter CCWest1
- Start date
Please see my attachment below (or above), regarding my feed thru option. Thanks!
I think it looks good
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Looks like you're doing your diversification calculations wrong by doing completely separate calcs for the combined garage and trailer feeder. Combine the loads prior to diversification as they are all on same service. This will lower your overall demand, because of the diversification.
Seems you're making this a little over convoluted. 340.40 Exception 2 allows 2 service feeders to one location supplying 2 meters with disconnecting means at the pedestal. From there, first trailer near pedestal not a problem as it is within the 30ft line of site. Second feed goes to garage and trailer, again no problem just need the 4 conductor from the pedestal to the garage (required for any sub panel feed). At garage just need to add a 100A Disconnect inline on exterior between the garage and the trailer within the 30ft line of site limits. No need for a neutral disconnecting type switch. Also, don't see an issue with the trailer disconnect being on the side of the garage (would meet code).
Simplest (and cheapest) way of load management for a gen set is with load shedding units, and no more space requirement as doing a "critical load panel, and no convoluted wiring back and forth from garage to trailer and back. Add the ATS at the garage main panel (as normal) and then feed through for the Trailer disconnect. The Load shedding units (load management) I've used monitor the individual load and the gen load and you choose priority of the individual load shed sequence. The self contained units I've used will control up to four 20-100A loads. and dry contacts for HVAC if you want to control that way. They also have expandable pack that will allow larger load quantities.
So say your priority is likely heat (non-shedding) - water - lights - cooking and last EV or laundry. It can be programmed that you determine the priority of load shedding, and it could be set so that "if" there is enough available power the EV charger may even be allowed without shedding and if loads increase it then will shed. Can be set as a permanent lock out when on Gen or monitored lockout that will restore if overall loads drop below established set point.
Seems you're making this a little over convoluted. 340.40 Exception 2 allows 2 service feeders to one location supplying 2 meters with disconnecting means at the pedestal. From there, first trailer near pedestal not a problem as it is within the 30ft line of site. Second feed goes to garage and trailer, again no problem just need the 4 conductor from the pedestal to the garage (required for any sub panel feed). At garage just need to add a 100A Disconnect inline on exterior between the garage and the trailer within the 30ft line of site limits. No need for a neutral disconnecting type switch. Also, don't see an issue with the trailer disconnect being on the side of the garage (would meet code).
Simplest (and cheapest) way of load management for a gen set is with load shedding units, and no more space requirement as doing a "critical load panel, and no convoluted wiring back and forth from garage to trailer and back. Add the ATS at the garage main panel (as normal) and then feed through for the Trailer disconnect. The Load shedding units (load management) I've used monitor the individual load and the gen load and you choose priority of the individual load shed sequence. The self contained units I've used will control up to four 20-100A loads. and dry contacts for HVAC if you want to control that way. They also have expandable pack that will allow larger load quantities.
So say your priority is likely heat (non-shedding) - water - lights - cooking and last EV or laundry. It can be programmed that you determine the priority of load shedding, and it could be set so that "if" there is enough available power the EV charger may even be allowed without shedding and if loads increase it then will shed. Can be set as a permanent lock out when on Gen or monitored lockout that will restore if overall loads drop below established set point.
Thanks Fred,
This is good info if I decide to stay with the 2nd mobile at the garage, but, I'm not sure you saw my post about possibly changing my plan by going with a small modular house instead of the 2nd trailer (mobile home) next to the garage. It comes with a 200A panel. Please see on page 1 of this thread.
Fred,
340.40 Exception 2? Is that a typo? I think you meant 230.40 Exception 2, yes? At any rate, In my original post of Feb. 16, I was figuring on two separate service conductors for each of the two mobiles and garage. It looks like 230.40 Exception 2 would allow that per NEC. Your response to this on Feb. 17 was, "Size service from POCO pole to Meter pedestal would need to be appropriate for entire site. POCO (NYSEG) would not normally provide 2 separate services onto the site." I take it you were cautioning me that it may not fly. To me, running two separate services from POCO to the pedestal with disconnects for each at the pedestal would be the easier way to go, than running one set of entrance conductors to a tap box at the pedestal to feed the two meters. Here's my questions:
(1) Should I try submitting my plan for 2 separate services per 230.40 Exception 2 anyway and see if they would allow it?
(2) You mentioned above that the garage panel needs to be considered a sub panel, feeders to the garage would need to be 4 wire. Is it considered a sub-panel because of the service disconnect at the pedestal?
Thanks!
I concur with Freds comments, you'll get some diversity back from the garage loads on a general calc for the entire service. Since a detached garage is not part of the manufactured home I suppose you'd be limited to a general calculation for the service anyways.
Regarding the load shed modules; They have pros and cons, and it depends on the end user, I have had mostly bad experiences with them, over the last decade many callbacks and frustrated customers that ended up with overloaded generators.
For me having the ATS just do a critical loads panel is simpler in the long run and less headache especially for larger homes or properties with separate structures as I have a clearly defined panel where generator backed up loads go.
A couple of other comments on the revised design;
I would supply the ATS from a 100A breaker in the 8/16 on the garage, no need for it to come from the 200A panel at the mfrd home.
And you dont need a ground rod at the generator
Regarding the load shed modules; They have pros and cons, and it depends on the end user, I have had mostly bad experiences with them, over the last decade many callbacks and frustrated customers that ended up with overloaded generators.
For me having the ATS just do a critical loads panel is simpler in the long run and less headache especially for larger homes or properties with separate structures as I have a clearly defined panel where generator backed up loads go.
A couple of other comments on the revised design;
I would supply the ATS from a 100A breaker in the 8/16 on the garage, no need for it to come from the 200A panel at the mfrd home.
And you dont need a ground rod at the generator
Thank you.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
yes typo.
230.40 Exception No. 2:
Where two to six service disconnecting means in separate enclosures are grouped at one location and supply separate loads from one service drop, set of overhead service conductors, set of underground service conductors, or service lateral, one set of service-entrance conductors shall be permitted to supply each or several such service equipment enclosures.
230.2 Number of Services.
A building or other structure served shall be supplied by only one service unless permitted in 230.2(A) through (D). For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service.
View attachment 2575967
The NYSEG pole with your underground going up is the service point.
Normally NYSEG won't but with 2 fully Independent meter and disconnects but meeting the requirements of NEC above. You might be able to vet this with the NYSEG engineer. Your original design showed one service that just landed at the pedestal for a meter and went on without overcurrent protection and another that also went to the pedestal but with overcurrent and an EVSE not meeting the 230.2 and 230.40 requirements for the 2 services.
Yes, with overcurrent at the pedestal.
Attachments
OK Fred, Thank you. I will fix my design concerning the disconnects, etc. and send it to NYSEG, and see what happens. Thanks for your advise!