Is this service 1PH or 3P - Keep getting conflicting answers

[arnagas]

Please refer to attached.

When I see this riser diagram I see a 3 Phase 1200A Meter Main.

I have someone telling me the following "[FONT=&quot]The plansindicate the main is 120/240 which is single phase. The 4 sets is the number of conduit and the (3) is the quantity of the wires."

[/FONT]I am not sure how they are going to land 4 sets of conduit on a single phase breaker. But maybe I am missing something

Who is right?

 

[Smart $]

If apartments, single phase. Three phase would be 4 wires

 

[ggunn]

Please refer to attached.

When I see this riser diagram I see a 3 Phase 1200A Meter Main.

I have someone telling me the following "The plansindicate the main is 120/240 which is single phase. The 4 sets is the number of conduit and the (3) is the quantity of the wires."

I am not sure how they are going to land 4 sets of conduit on a single phase breaker. But maybe I am missing something

Who is right?

Where do you see three phase? Whoever drew it up crossed a zero, which is often done to distinguish it from the letter O; is that what you are seeing as the letter phi?

 

[Ingenieur]

Confusing
3 each 4" conduits (they only show 3 conduits, not 4)
but 4 sets x 3 conductors? (Should be 3 sets x 4 conductors?)

likely 1 ph L1, L2, N

could be ea conduit 3 ph plus N?

 

[infinity]

Seems very clear to me that it's 1Ø because there are 3 SEC's in each raceway. Not sure why someone would think otherwise.

 

[Ingenieur]

Seems very clear to me that it's 1Ø because there are 3 SEC's in each raceway. Not sure why someone would think otherwise.

3 conduits
12 conductors (they say 4 sets of 3, should be 3 sets of 4?)
4 conductors per conduit

if 4 conduits (they show only 3) then 4 sets x 3 makes sense

 

[jumper]

Confusing
3 each 4" conduits (they only show 3 conduits, not 4)
but 4 sets x 3 conductors? (Should be 3 sets x 4 conductors?)

likely 1 ph L1, L2, N

could be ea conduit 3 ph plus N?

I am going with 1 ph, 4 sets of 3W despite only showing 3 conduits.

3 sets of #500 AL is only 930A. Need 4.

 

[infinity]

3 conduits
12 conductors (they say 4 sets of 3, should be 3 sets of 4?)
4 conductors per conduit

Why would there be 4 conductors/conduit if it's single phase? Unless I'm missing something I see nothing to indicate that it's 3Ø.

 

[Ingenieur]

Why would there be 4 conductors/conduit if it's single phase? Unless I'm missing something I see nothing to indicate that it's 3Ø.

they show 3 conduit
spec 4 x 3 conductors
4 conductor/conduit

could be a dwg error

 

[infinity]

they show 3 conduit
spec 4 x 3 conductors
4 conductor/conduit

could be a dwg error

Correct it only shows three conduits but it clearly says 4 sets of 3-500's in each conduit.

 

[zbang]

they show 3 conduit
spec 4 x 3 conductors
4 conductor/conduit
could be a dwg error

(3) sets of (4) conductors makes much more sense when only three conduits are shown. And 1200a is large for a single-phase service IME.

Time for an RFI.

 

[jumper]

Correct it only shows three conduits but it clearly says 4 sets of 3-500's in each conduit.

:happyyes:

Only way to get 1200A 3 PH with #500 AL is gonna be 4 sets of 4-500's.

 

[Ingenieur]

Correct it only shows three conduits but it clearly says 4 sets of 3-500's in each conduit.

4 sets of 3 500's per conduit? 12 500's per conduit?

I read it as 4 sets of 3x500 in 3 conduits
makes no sense
3 sets of 4x500 in 3 conduit
makes sense

confusing

 

[jumper]

4 sets of 3 500's per conduit? 12 500's per conduit?

I read it as 4 sets of 3x500 in 3 conduits
makes no sense
3 sets of 4x500 in 3 conduit
makes sense

confusing

#500 AL is only 310A at 75C

 

[infinity]

#500 AL is only 310A at 75C

Although they only drew 3 conduits the fact that it is 4 sets of 3-500's in each set is very clear. You don't get 1200 amps with 3 sets.

 

[Ingenieur]

#500 AL is only 310A at 75C

yep
that is why it makes no sense
3 conduit with 4x500 each (3 sets of 4-500's)?
as shown nothing adds up
we can assume 4 conduit but it clearly shows 3

 

[Cow]

Who runs 3/0 CU to rebar???? And in a tiny 3/4" conduit no less....:roll:

 

[Ingenieur]

RFI time

 

[kwired]

You would think the utility would want to supply this with three phase, unless the load just isn't there and/or it is in too remote location with no three phase readily available.

 

[steve66]

You would think the utility would want to supply this with three phase, unless the load just isn't there and/or it is in too remote location with no three phase readily available.

I was just about to say the same thing. I don't think many utilities will provide a 1200 amp single phase service.

I'd say there is a good chance Ingenieur is right, and its a typo.