- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If single phase does not consist of 2 phases and 3 phase consists of 3 phases why is a 208V pump connected to 2 phases of a 3 phase system considered single phase?
Single Phase 208v Pump
- Thread starter Dennis Alwon
- Start date
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kwired
Electron manager
- Location
- NE Nebraska
Are you a newbie here? This gets asked a lot.
There is only one phase angle between the two points of supply (a straight line is 180 degree angle), so the load can't be anything but 208 volts across that 180 degree angle.
Now if you involve those two points as well as the neutral you do get more than just one phase angle and is why it is possible to derive three phase open delta systems with two phases plus neutral of a wye system as the primary side.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
At 208 volts, 3Ø system has 3 single phases, A-B, A-C, B-C, a 1Ø, 208 volt pump would only use one of the three phases.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Well I am in a discussion on another forum with engineers from over the pond that are arguing this with me. Someone showed a picture of a pump hooked to 2 hot wires and the person asked if it was single phase, 3 phase or 2 phase.
I said single phase and then the argument went on. I think it may be about language differences or perhaps what they consider it. I don't know
Check it out or join and enter the discussion. https://zone4engineer.com/forums/topic/20/3ph-motor/view/page/1
I said single phase and then the argument went on. I think it may be about language differences or perhaps what they consider it. I don't know
Check it out or join and enter the discussion. https://zone4engineer.com/forums/topic/20/3ph-motor/view/page/1
- Location
- New Jersey
- Occupation
- Journeyman Electrician
A old 2Ø system has the phases 90° apart. That's nothing like our modern 3Ø systems.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
- Location
- New Jersey
- Occupation
- Journeyman Electrician
We know the difference and it's called single phase. Good luck with trying to convince them. :roll:
where's Besoeker ?
Walking my big handsome collie - where else?
I think he has worked out that I have problems with my vision and sticks close to me. My minder.
And I think the single phase, two phase discussion has been done to death.
Two hots 180 deg apart.........
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Walking my big handsome collie - where else?
I think he has worked out that I have problems with my vision and sticks close to me. My minder.
And I think the single phase, two phase discussion has been done to death.
Two hots 180 deg apart.........
It is really not about single phase 180° apart. It is about the 3 phase and using 2 phases for the pump and being called single phase.
OK.
But he really is a handsome beast with such a lovely temperament.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Because there is only one sine wave across the load.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
190203-1546 EST
A two terminal device is a single phase load no matter what it is connected to. In the broad sense this goes all the way down to zero frequency, DC.
.
A two terminal device is a single phase load no matter what it is connected to. In the broad sense this goes all the way down to zero frequency, DC.
.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
This.
We can argue _forever_ about one versus two phase with systems that have a 180 degree phase difference (or an apparent 180 degree phase difference depending on where you stand in the debate). But the question of a 2 terminal device is separate.
With two terminals you only have a _single_ circuit with a single electrical phase angle.
It doesn't matter what the 'phase to neutral' phase angles of the supply system are, or how many different phases there are in the supply system. That 208V could come from a 240:208V single phase transformer, or it could come off of two separate phases from a 208/120V wye system, or it could come from a single leg of a 360208V wye system, or it could come from two separate phases of a '2 phase 5 wire' system with 147V line to neutral. All the load cares about is the voltage between the two connected terminals.
So it is perfectly reasonable to say that you have a single phase load connected to two phases of a three phase system
-Jon
kwired
Electron manager
- Location
- NE Nebraska
This.
We can argue _forever_ about one versus two phase with systems that have a 180 degree phase difference (or an apparent 180 degree phase difference depending on where you stand in the debate). But the question of a 2 terminal device is separate.
With two terminals you only have a _single_ circuit with a single electrical phase angle.
It doesn't matter what the 'phase to neutral' phase angles of the supply system are, or how many different phases there are in the supply system. That 208V could come from a 240:208V single phase transformer, or it could come off of two separate phases from a 208/120V wye system, or it could come from a single leg of a 360208V wye system, or it could come from two separate phases of a '2 phase 5 wire' system with 147V line to neutral. All the load cares about is the voltage between the two connected terminals.
So it is perfectly reasonable to say that you have a single phase load connected to two phases of a three phase system
-Jon
Could even come from between two taps of a single coil with 100 different taps on it.
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