Using 3 phase panel as single phase

Status
Not open for further replies.
M

Maverick99

Member
I have a problem in that I have to add a meter and panel to a 240/480 single phase service. Quite an odball and I can't seem to find a supplier that can supply a NEMA 3, 480 Volt single phase panel. They can all supply a 3 phase panel.

I have not been able to find anything in the codes that preclude me from using a 3 phase panel as single phase, but I am afraid that I am just missing it.

Can anyone help me with this?

Thanks
 
Your power supply is not one for which panels are tested, so there really are no 'listed' panels available to you. Perhaps you can pay a kings' ransom for a custom panel; otherwise, it's DIY time.

Technically, you are precluded from using a three-phase panel in the application because your service is not one of those included in the instructions on the panel cover.
 
renosteinke said:
Technically, you are precluded from using a three-phase panel in the application because your service is not one of those included in the instructions on the panel cover.
Click to expand...

I am not sure I agree or believe that anyone would red tag it. I have hooked up single phase panels for PV and only used one phase. Not quite the same but what would be the issue?
 
It is used to power lighting at a baseball field. There is currently 1 service there that I have to break into 2 services due to OUC's billing practices.
 
renosteinke said:
Your power supply is not one for which panels are tested, so there really are no 'listed' panels available to you. Perhaps you can pay a kings' ransom for a custom panel; otherwise, it's DIY time.

Technically, you are precluded from using a three-phase panel in the application because your service is not one of those included in the instructions on the panel cover.
Click to expand...
Are you sure about this?

Although, I am not aware of any manufacturer specifically excluding 240/480 1PH 3W from their panels that are listed as "600V 3PH 3W max".
Square D I-line panels are shipped with three bus bars, but 'become' single phase when only the A and C phase are used. Their 480V breakers carry 1-phase AIC ratings @ 240V. And, my 2004 edition of Siemens' SPEEDFAX also lists 480V breakers with 1-pole 240V AIC ratings (i.e. ED4).
 
jim dungar said:
Are you sure about this?

Although, I am not aware of any manufacturer specifically excluding 240/480 1PH 3W from their panels that are listed as "600V 3PH 3W max".
Square D I-line panels are shipped with three bus bars, but 'become' single phase when only the A and C phase are used. Their 480V breakers carry 1-phase AIC ratings @ 240V. And, my 2004 edition of Siemens' SPEEDFAX also lists 480V breakers with 1-pole 240V AIC ratings (i.e. ED4).
Click to expand...

Are you sure about this? ;)

From SqD's I-line catalog:
I-Line circuit breaker panelboards can be used on the following
system voltages:
? 120/240 VAC; 1-phase, 3-wire
? 240 VAC; 1-phase, 2-wire
? 240 VAC; 3-phase, 3-wire
? 240 VAC Ground, B-phase; 3-phase, 3-wire
? 208Y/120 VAC; 3-phase, 4-wire
? 480Y/277 VAC; 3-phase, 4-wire
? 480 VAC; 3-phase, 3-wire
? 600Y/347 VAC; 3-phase, 4-wire
? 600 VAC; 3-phase, 3-wire
? 125/250 VDC; 3-wire
? 250 VDC; 2-wire
Click to expand...
There is some question as to whether this is an all inclusive list.
 
Dennis Alwon said:
Wow, never saw 240V to ground. What is it used for?
Click to expand...


480/240 single phase transformers are common around here feeding irrigation machines where POCO has no three phase available. Customer usually has to use a rotary phase converter to get three phase.

There are hydraulic driven systems that only have a 10 or 15 hp pump for electrical - they often use a 480 volt single phase motor for these if single phase is all that is available - not something you probably see many other places.

If three phase is available they usually provide open delta derived 480/240 three phase - it has a high leg of approximately 415 volts.

When hooking up the single phase systems we typically are only serving a single load so we just use three pole fused disconnects (because they are stocked and cost less because of that) and only use two poles. That may be best way to go for the OP unless he has several branch circuits then maybe look into I-Line. Most other panel designs even if acceptable to use for the voltage will mean only 2/3 of the spaces will be available. I-Line can use all spaces you just order breakers with proper buss connections.
 
Smart $ said:
There is some question as to whether this is an all inclusive list.
Click to expand...

That is my point, if the panel is rated as 480V to ground (i.e. 3PH 3W), does it specifically exclude being used as 240/480? We know the 1-pole breakers are rated for both 240V and 480V.
 
jim dungar said:
That is my point, if the panel is rated as 480V to ground (i.e. 3PH 3W), does it specifically exclude being used as 240/480? We know the 1-pole breakers are rated for both 240V and 480V.
Click to expand...
I had replied to your post, but it is missing because of restoration after the recent hack attacks provided only posts saved to backup before the forum went down.

I recall writing: I don't know one way or the other.

There was more, but I forget exactly what I wrote...

Are the system voltages stated in the catalog considered part of the UL listing?

If yes, I would say 240/480 is excluded (at least for Square D's I-line models).

If not (for I-line's), exclusion would depend on what is stated on the panelboard's label. I don't have access to a label right now, so 240/480 may not be excluded.
 
Just wanted to say I deal with single phase 240\480 all the time in street lighting applications. Just finnished a freeway expansion and installed a new controll cab. The manufacturer was Browning out of Seattle.
 
Smart $ said:
I...
If not (for I-line's), exclusion would depend on what is stated on the panelboard's label. I don't have access to a label right now, so 240/480 may not be excluded.
Click to expand...
Forgot to include "instructions", which are also part of the listing.
 
Darken222 said:
Just wanted to say I deal with single phase 240\480 all the time in street lighting applications. Just finnished a freeway expansion and installed a new controll cab. The manufacturer was Browning out of Seattle.
Click to expand...

Thank you for that information and welcome to the forum.
 
Status
Not open for further replies.
Top