Do you think in heating mode those linesets are a concern, or separation is needed. On one hand, they are insulated (no seam on the insulation), and the SER is against the top plate (i.e. little insulation behind it) while heating would only run under cool/cold conditions. On the other hand, they do carry heat.
The only regulatory concern would be if one can argue that the line set piping gets hot enough that the ambient temperature of the cable can rise above 109F. I have no idea if that's a real possibility or not. If the HVAC lineset pipes get hot enough that the cable sees an ambient above 109F, then you should add some separation. But you have the cable above the 4 line sets, so the line sets would have to get well above 109F for that to be the case (versus if you bundled the cable in the middle of all 4 line sets).
They run in parallel for a good 40'. In one location (exiting the mechanical room, they go through a constriction. In other places they are closer than the image, but intermittently. My gut says the same as you, in that a little more separation, where possible would be beneficial. When the mini-split guy comes back out, I will ask if they can be stretched down maybe 3-6" for a little clearance. Since the outside wall will always be cool/cold when running heat, I think risk is negligible. I'll also do a sanity check with those heads running on high to see how warm the lines get, both inside and outside the insulation.
But, I will post up a separate thread on energy management topics, if you have any insight that you wish to share.
If Xcel Energy is your POCO, see page 45 of this document: https://www.xcelenergy.com/staticfiles/xe-responsive/Admin/Managed Documents & PDFs/Xcel-Energy-Standard-For-Electric-Installation-and-Use.pdf
I haven't actually worked in this world, not directly. I expect most of your questions to be answerable by studying the above document.
If you have an overhead service, then generally the service point is the splice at the top of the mast between the service drop and the conductors in the mast. The service drop conductors are the POCO's responsibility, and the conductors in the mast are Service Entrance Conductors.
Which doesn't matter for you as you have two service OCPDs supplied by one set of SECs, so the sum of the OCPD ratings may exceed the ampacity of the SECs. The SECs are protected against overload by the load calculation only.
I would trust the document over a given person's understanding. If their misunderstanding is an impediment to the process, just refer them to that page of that document and ask them to explain.
Do you really have a 60A EVSE, which would require a 75A circuit, or do you have a 48A EVSE, which requires a 60A circuit? You only need to apply the 125% factor once.
but, as a condition of the permit I have to pre-wire or put in conduit. Since EVSEs seem to be going through their own evolution now (single breaker pool, load sharing, energy mgmt, etc) and we are a year two out from EVs, it was more of a placeholder on the basis of 3 EVs @ 20A each, or a pool of 60A available. I would have preferred a pool of 80A available, but the numbers weren’t working out.
I think I've now dealt with 5 people at Xcel or their contractors that are not clear about it. You can hear it in their voice when talking to them. It seems that NEC and POCOs need to do something to add clarity. I awoke this morning thinking about that more... it seems like NEC should include a table for services to outline their continuous and non-continuous ratings and that POCOs need to publish some bulletins and/or training to their staff. With the electrification movement, more and more residences are going to be having 320A services, and if the electricians are undersizing the conductors because they think it's only good for 320A, that's no bueno.
I must have been doing my load calcs by optional method in the middle of the night or something... they were coming back larger than the standard method. I'm glad you mentioned this (Thank you!) and I went back, as it notably lowered the load on the service entrance conductors, as you can see below. Of course, the 180A service conductors are still an issue, and now the garage/studio leg is slightly over.
Right, but their internal reference to resolve their lack of clarity is the document we are talking about. So you only have a problem if you need them to recognize what the document says, and after consulting the document they still disagree.
Correction, you have no 180A service conductors; your 4/0 Al are feeders. And as partial feeders (not carrying the entire dwelling unit load), they can't use the optional method.
Excellent question, it is not defined and is a source of ambiguity. See, e.g.
That is true - I have it in writing, and all I need. Though I'm thinking more about how broader humanity is impacted. I'm only mentioning the below rant, as I'd value your below input if you think there is a valid NEC PI submittal, coupled with a reach out to Xcel senior management. I awoke early yesterday thinking... wow, this is a massive knowledge gap that affects customers, and possibly safety... there must be a way to improve this.
Who knows how I messed up the calc so badly, but at least it put me in a better position.
I'm honored you would go for clarity, inspired by my topic. Thank you very much. The timing of that any my definition question is a little funny.
Unless you're trying to get the electrician who did the earlier work to upsize either the 500 MCM Al or the 4/0 Al, I don't see how it impacts you that the inspector is mistaken. You know that with the existing conductors you need the standard load calc to be 180A or under on each 4/0 Al feeder. So either allocate the loads to make that work, or upsize one or both of the feeders.
I am actually trying to get the electrician to upsize the 4/0 Al conductors to be what we believe would be compliant, as I don't think I should go hire a second electrician to do it.
Thanks, Wayne. You've really been great to me - and I appreciate your support.
Presumably you mean potential code violation--the violation doesn't exist until the load on the 4/0 Al feeders exceeds 180A.
This is awkward, but...
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