Two Section Panelboards

[Anonymous]

Does any one know how to make a 2 section panel schedule for panelboards that are more than 42 circuits?

Since the panelboard has to be split, the panel schedule has to be split too.

I tried making the panel number of circuits 84, and revit creates on long panel schedule.

I thought of another way to work around it by using two panels side by side (aligned) but then their panel schedules will both go from 1 to 42. 

I wonder if there is a way to set a panel circuit numbering to start from 43 instead of 1.

[asommer]

Yes, We need this too.  We will be working around it, having the one panel sized as two put together.  I have a Wish List post for this.

[Martin__Schmid]

How would you expect this to work?

Do you want to place two separate Panels to represent a two-section panel? 

If you did place two separate panel objects, would you expect that certain properties *must* be the same?  I.e., somehow 'linking' the panels so they know they are related as a multi-section panel?

Would it be sufficient to leave the functionality as-is, but allow you to set the 'starting circuit number' of a panel to something other than 1?

[asommer]

Basically we would like it to represent as two seperate panels on a plan view, placed side by side with the same name. These two seperate panels are then fed from one power source and connected via main lugs inside the panel. Section one would contain circuits 1-42 and section two will contain circuits 43-84 and would use the same panel name for both sections (Sec. 1, Sec. 2). Panel schedules would also need to follow this format.

[Martin__Schmid]

So, sounds like you're looking for:

1. Ability to connect one panel to another via lugs (instead of a breaker).

2.  Ability to specify the starting circuit on a panel (i.e., 43 in your case, whereas now, all panels currently start with 1).

Would you need functionality so the Panels 'knew' they were a multi-section panel?  Or would the above functionality be sufficient? 

[asommer]

Yes, functionality would be great for diversities and overall load purposes, especailly if we start running voltage drop and short circuit calcs or sizing feeders with Revit. Getting the circuit numbers to start up at 43 and run to 84 is important as well.

[Martin__Schmid]

How would diversities and overall load funcationlity be different for the 'multi-section' panel vs. two individual panels?

[asommer]

Two seperate panels would be fed from two seperate power sources (i.e. - switch and fuse or circuit breaker in the distribution panels) a double section panel would use the same power source for both sections. Diversities probably wouldn't be affected much although it needs to be funtional so one line riser diagrams can be represented correctly, feeders can be sized correctly, etc. and people aren't confused when two panels appear on plan with the same name.

[Martin__Schmid]

let me ask it this way:

For diversities/overall load functionality, how would it be different for a MSB feeding:

1. Panel/Section A as a Multi-section panel (i.e., Section B fed from Section A on lugs)

vs.

2.  Panel A, where Panel A feeds Panel B through a breaker.

[asommer]

OK, lets say that option one is a sub-fed panel (i.e. - breaker in panel a feeds panel b) all the diversities from panel b no longer matter to panel a. The breaker and feeder are sized to whatever load is in panel b after diversities are applied.

Option two (i.e. double section panel where lugs are used to feed the 2nd section) is treated as one panel and all loads are added together after the diversities are applied.

I know this is a lot of info and I'n not doing a very good job explaining. Mainly this is a money saving issue in the industry. If two panels can be fed from one source, there are considerable savings by not having to provide a 2nd switch, fuse and feeder to accommodate the need for additional circuits for receptacle and lighting branch circuits.

[Martin__Schmid]

You're doing a great job explaining... I may be doing a bad job of asking questions :).  I've spent 5+ years answering questions, now learning how to ask questions :).

For the multi-section panel, previously it seemed you wanted one schedule for each section.  So, in some sense you seem to want to treat it as two panels. 

In that case, would one or the other schedules not show any load summary info? 

Would the load summary info for both scheduels show the same info (same values, etc?). 

Would certain info be omitted from one or the other schedules?

[asommer]

1.  The way we do this is each panel will have it's own schedule, Two section panels will have two schedules, but one load summary (our load summary is normally after the second section).

2.  I would think the first section does not need load summary info, maybe load totals for the first 42 circuits, maybe an option to choose where it shows.

3. That might be confusing to see same loads in two different schedules, It might be treated as two different panels in the field.

4. The second panel section will not have a main breaker, the first section will.

Just to let you know, I have a few different electrical designers chiming in here at different times, so I apologize for any contradictions that might have appeared  We thank you for your time and effort.  I will be posted all day, let me know if there is anything else.

-Adam

[Martin__Schmid]

For your point #1:

"The way we do this is each panel will have it's own schedule, Two section panels will have two schedules, but one load summary (our load summary is normally after the second section). "

You say 'normally' after the second section.  Why would this vary?  Would it be acceptable to always be after the 1st section?

Consider two separate cases:

a.  Section A feeds Section B using lugs as indicated previously.  This is considered a multi-section panel.  The panels are located in the same room, side-by-side. 

b.  Panel A feeds Panel B using lugs.  This is not considered a multi-section panel; the user assigns different names to each panel.

In scenario b, is Panel A and Panel B are equivalent to Section A and Section B in scenario a, as far as what the manufacturer would provide?

In Revit, how would you expect to distinguish between a multi-section scenario and a sub-fed panel scenario?

What on your schedule for Section A indicates that there is a second Section (i.e., a screen shot would be helpful here).

[asommer]

1.  We have developed a panel schedule block, including 2 section panels, that calculate loads and diversities.  We always put the loads summary after the second section, but might need to be adjusted to fit the sheet.

2. What we consider a 2 Section panel is really 2 separate panels, Panel A feeds Panel B via lugs with no breaker between, acting as 1 panel, but with 2 separate panel schedules for clarification.  A sub-fed panel we consider to be 2 separate panels, Panel A feeds Panel B via Circuit Breaker on panel A.

3. I believe a 2 Section panel should be it's own type, with a suffix of "Section 1" and "Section 2" (or a choice of suffixes?).  Each individual section needs to be placed individually, so maybe a function is needed to place the two panels and create a link between the two.  I can do a sub-fed panel now, for it puts a breaker in the first panel.

4.  We name both sections the same, but with a suffix as above.  also, we have a check box describing each panel feed, Breaker or Lugs.

I have attached a screen shot, the single panel on top is our normal schedule, the two below is our 2 section panel schedule.  Hopefully we can come together on this issue!

[Martin__Schmid]

1.  This can be done today using separate Templates, i.e., you could have one template that shows the load summary section, and the other template does not show the loads summary section.  Then, for the 'last' schedule, you can show the Loads Summary, but for the other 'previous' sections, you can use the template that doesn't show the loads summary.

2.  Sounds like the  the main new need here, then, is for a lug capability.

3.  Assuming a lug works like a breaker, then conceptually the linking could work the same way.. just instead of auto-assigning to a breaker, there needs to be some way to assign to lugs.  Is that what you need?

4. Again, this could be done with user-defined (i.e., shared parameters).    However, it was not clear in the image you posted how you show this check box for feed (breaker vs. lugs).  Can you post the dwg and/or provide another image 'zoomed in' highlighting this detail?

[asommer]

Yes, a Lug connection option instead of automatically adding a breaker would be critical.  Maybe a choice could be given when connecting one to the other, changing the type of panel or panel schedule.  The main concern we have with this is will the revit know the difference between two separate panels and a 2 section panel?  I would assume so if the "Lug" connection was available, but the panel schedule would then need to recognize that it is a 2 section panel.  As you saw with the jpg, each section has it's own schedule (to keep things nice and consistent) but treats two as one when applying diversities.

As far as the #4 you posted, the check box (not really a box, sorry) is at the top right corner, and this is just a manual text, it does not modify the calcs.  We just put an X where it applies, for documentation.  the 2 section panel schedule we use is a separate block from the single above it, so the load summary reads both panels (all 84 circuits) and diversivies them as one panel.  You may notice on each schedule, next to description, is load type.  This is where we assign the load classification to each circuit.  the load summary reads this, multiplies it by the demand factor, and gives the total adjusted load as one.  If I had two individual panels and load summaries, the loads could possibly come out different.

The reason why these would come out different is in the demand factors, if we set the demand factor to be less than 100% over a certain VA,  Two panels put together in a 2 section configuration might meet that diversity and drop the total load.  If there were two individual panels, neither will probably meet the load limit to apply the diversity.  It is critical that the Revit understands that, and doesn't go ahead and diversify each individually anyway, even if i'm not displaying it in a schedule.

To be honest, we need to play with this a bit more to understand what "Revit" is talking about.  The Load Classifications and Demand factors are a GREAT addition to the Revit.  Just need this little bit more and we could use the Revit to do electrical calcs.

[Martin__Schmid]

>> The main concern we have with this is will the revit know the difference between two separate panels and a 2 section panel?

What differences would you expect there to be between two separate panels vs. a 2 section panel?

>> If there were two individual panels, neither will probably meet the load limit to apply the diversity.  It is critical that the Revit understands that, and doesn't go ahead and diversify each individually anyway, even if i'm not displaying it in a schedule.

This is how revit already works when one schedule is fed from another.  I.e., If Panel B is fed from Panel A via a Breaker, Panel A will show the total connected load info for both panels, and apply diversity over all these totals.  Panel B sees no load from Panel A, thus it's load summary only shows the connected/diversity for that panel. 

Example:  Panel A has 14kva of receptacle load directly connected.  Panel B has 12kva of receptacle load.  Panel A feeds Panel B.

Recptacles demand is 100% for the first 10kVA and 50% for the remaining.

Thus, the demand on Panel B is 11kva.

The connected load on Panel A is 26 kva.  The demand is 18kva. (10kva + 1/2 of 16kva).

Conceptually, how are lugs are different from a breaker as far as establishing the real-world relationships between panels and conceptually carrying loads through on the feeder to the 'first' panel. 

I understand you want to see the total from both panels on Section B.  Panel/Section A still feeds Panel/Section B, but through lugs instead of a breaker.  The Load Summary for Panel A (i.e., the feeder to panel A) would thus consider the total connected from both panels, and the diversities accordingly.  However, what you're asking for is that Panel/Section B see the load 'from above' in Panel/Section A.  In reality, does Section B see the load from Section A?  I.e., there is a feeder between Sections A and B... would that feeder 'see' the load from Section A and feed it to B?

Let me ask this.. is it valid to have a 225A panel feed a 100A panel with lugs instead of a breaker? 

[asommer]

A 2 section panel is treated as a single 84 circuit panel. Currently,  there is no 84 circuit panel, it is too big, no manufacturers build one.  They use 2 panels, connected by Lugs.

Scenario 1... You have a Panel B, SUBFED from panel A by Circuit breaker.  You would apply diversities to Panel B, get a total load, size the feeder, size the CB, and connect to Panel A.  The diversities from Panel B have already been applied, and should NOT be diversified again by Panel A calcs.  The Panel A circuits and diversities get added to the Panel B total load, then you have a total load for Panel A.

Scenario 2...  You have a 2-Section Panel- calculated as ONE large 84 circuit panel, only split into two boxes due to size constraints, connected via Lugs.  Here, you have double the circuits, which allows a greater possibility for the diversities to be applied.  you do NOT calculate the two sections separately, as you would in Scenario 1.

This is one of the differences between the two.  Sometimes, they may be the same, if the diversities are not met by either scenario, but not likeley.

{Example:  Panel A has 14kva of receptacle load directly connected.  Panel B has 12kva of receptacle load.  Panel A feeds Panel B.

Recptacles demand is 100% for the first 10kVA and 50% for the remaining.

Thus, the demand on Panel B is 11kva.

The connected load on Panel A is 26 kva.  The demand is 18kva. (10kva + 1/2 of 16kva).}

scenario 1- Panel B demand is 11kva, Panel A demand is 12kva.  You would not Diversify the load from panel B again within Panel A, the total loads would just be added together.  The demand for panel A should be 23kva.  The diversities should be applied at each panel individually, and done only once.

Scenario 2- Section A and B are calculated as one panel- receptacle load is 26kva, then gets diversified to demand 18kva, as you have in your example above.  Section B has no circuit breaker, is just an extension of Section A via Lugs.  They are considered ONE panel.  Really it doesn't matter where the loads summary shows up, as long as the calcs are good.

{Let me ask this.. is it valid to have a 225A panel feed a 100A panel with lugs instead of a breaker?}

This would not be applicable- You would need overload protection for the 100A panel in the form of a Circuit Breaker, making the 100A panel a Subpanel to the 22A.

To add to the confusion, there could be 3-Section and 4-Section panels, also.

[Martin__Schmid]

>>This would not be applicable- You would need overload protection for the 100A panel in the form of a Circuit Breaker, making the 100A panel a Subpanel to the 225A.

Oh, yes, ... so should there be certain characteristics of the sub-sections that must be kept the same as the 'first' section?  Would you expect Revit to do this automagically?

>> Scenario 1... You have a Panel B, SUBFED from panel A by Circuit breaker.  You would apply diversities to Panel B, get a total load, size the feeder, size the CB, and connect to Panel A.  The diversities from Panel B have already been applied, and should NOT be diversified again by Panel A calcs.  The Panel A circuits and diversities get added to the Panel B total load, then you have a total load for Panel A.

>> scenario 1- Panel B demand is 11kva, Panel A demand is 12kva.  You would not Diversify the load from panel B again within Panel A, the total loads would just be added together.  The demand for panel A should be 23kva.  The diversities should be applied at each panel individually, and done only once.

I'm not suggesting that you'd apply diversity on the diversified load comming from Panel B into Panel A... I'm merely taking the total connected receptacle load and applying diversity to that.  220.44 makes no distinction on whether load diversity has already been applied on a sub panel.  Certainly you can do the way you suggest as it is conservative.  However, if you have (4) panels each with 12kVA connected load, you'd have 11kVA diversified each.  If these 4 panels are fed from a common MDP, that MDP panel 'sees' 48kVA of connected receptacle load, and applying 220.44, the diversity may be applied as 10 + 1/2 * 38 = 29.  Would you disagree?

[asommer]

I'm sorry, but I'm out of my league here.  I have been talking to our engineers and designers, some of them were writing these posts.  I get contradictions in the way the panels are calculated.

A Lug-fed option would be nice for sub-fed panels, if that makes sense.  I guess that will do for a 2section panel.