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New Member
Jeremy2000
Posts: 2
Registered: ‎04-13-2011
Message 1 of 9 (773 Views)
Accepted Solution

Transformer Primary Side automatic wiring sizes

773 Views, 8 Replies
04-13-2011 08:06 AM

I have a 3 Phase 3 wire transformer with a 480v delta primary voltage. Is there anyway to circuit this up to the switch gear without a neutral wire? I have created a 480v Delta 3 wire distribution system in the electrical settings and assigned it to the transformer yet still it shows a 3 hot conductors and a neutral??

I'm using 2014.  I disconnected the panel fed from the secondary side of the transformer, then I was able to change the wire type without a neutral.  I connected the panel back, and the wire type stayed in tact not showing the neutral.

Contributor
markmcmicheal
Posts: 25
Registered: ‎08-24-2007
Message 2 of 9 (760 Views)

Re: Transformer Primary Side automatic wiring sizes

04-14-2011 07:09 PM in reply to: Jeremy2000

Have you tried selecting the primary side wire and changing the neutral count in the properties pallete to "0"?

New Member
Jeremy2000
Posts: 2
Registered: ‎04-13-2011
Message 3 of 9 (753 Views)

Re: Transformer Primary Side automatic wiring sizes

04-15-2011 06:09 AM in reply to: markmcmicheal

I can change the tick marks, but as far as voltage drop and wire size calcs, Revit still includes the neutral.

New Member
msargent
Posts: 1
Registered: ‎02-06-2013
Message 4 of 9 (416 Views)

Re: Transformer Primary Side automatic wiring sizes

02-11-2013 12:26 PM in reply to: Jeremy2000

Did this ever get resolved?  Seems to still be an issue (Revit MEP 2012).  Revit doesn't give you the ability to edit the wire count (it's greyed out).

Active Member
shawnh
Posts: 7
Registered: ‎04-12-2013
Message 5 of 9 (288 Views)

Re: Transformer Primary Side automatic wiring sizes

06-26-2013 04:45 PM in reply to: msargent

Still a problem in 2014? When are we going stop being ignored electrically? Why is this and homeruns still a problem?

Contributor
jomazq
Posts: 12
Registered: ‎11-07-2012
Message 6 of 9 (161 Views)

Re: Transformer Primary Side automatic wiring sizes

04-16-2014 06:51 PM in reply to: shawnh
I'm experiencing the same problem . This is a challenge to my attempt to use a system defined feeder schedule.
Contributor
pteague
Posts: 15
Registered: ‎09-19-2011
Message 7 of 9 (61 Views)

Re: Transformer Primary Side automatic wiring sizes

08-18-2014 01:19 PM in reply to: Jeremy2000

I seem to have found a workaround for this problem.  It's not great, but if you use it from the beginning, it seems to work okay.

 

If you already have the transformer in the system, copy it (ctrl-c).  Now, delete it.

 

Next, paste aligned to same place (or however, you want to get it back in the model).  This will keep the name and other instance properties from being deleted.

 

Next, connect the primary side to the panel that serves the transformer.  This should make a new circuit in the exact same place in your panel.  If you named your circuit or have conduit sizes or breaker sizes inputted, you will need to re-input these.  If everything went according to plan, your new circuit should be neutral-free (because when you attached it to the serving panel, it was a balanced, albeit zero, load).

 

Now, you should be able to connect the secondary side to the transformer, and the feeder serving the transformer should still be neutral-free, even though it is now unbalanced.  You should not have to re-input the information for the secondary side circuit because you did not deleted the secondary side panel.

 

If you're starting with a new system, if you connect primary first, then secondary, I think this should work for a full project.

 

I have not tested this extensively, but I have tested it in a model that I am currently developing and ran into the same problem with neutrals on delta circuits.

 

Hopefully this works for you guys!

Contributor
pteague
Posts: 15
Registered: ‎09-19-2011
Message 8 of 9 (52 Views)

Re: Transformer Primary Side automatic wiring sizes

08-18-2014 08:48 PM in reply to: pteague
Update:

I've done a little more testing, and I found some things you need to make sure you do in order.

When connecting the primary side to its serving panel, you need to set the breaker size, wire type, and any other "circuit" variables before you connect the secondary side. Once you connect the secondary side (unbalanced load), any changes you make to the primary circuit (breaker size, wire type, etc.) will cause Revit to add a neutral to your circuit.
New Member
mdurman
Posts: 1
Registered: ‎01-16-2013
Message 9 of 9 (19 Views)

Re: Transformer Primary Side automatic wiring sizes

09-10-2014 11:49 AM in reply to: pteague

I'm using 2014.  I disconnected the panel fed from the secondary side of the transformer, then I was able to change the wire type without a neutral.  I connected the panel back, and the wire type stayed in tact not showing the neutral.

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