Another one for "Pole Pig" spotters-have you seen a three phase service derived from 2 primary wires-and two transformers-that is an "open Delta" three phase-I have dealt with one and seen another.A radio station transmitter site had this-and the dump I go to get rid of my trash has one to run their Marathon compactor.Its fine for motor loads but not as good for rectifier or electronic loads such as transmitters.The open delta is another way to get 3 ph without a rotoverter in areas where the real three phase isn't available.Usually open delta is 220V.
1-Phase, 2--Phase, 3-Phase...
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sudsmaster
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I'm thinking that for front load washers, simply switching the motor from 3 phase to single phase isn't as easy as it may sound. That's because 3 phase motors are a simpler design, without the need for a starting circuit/capacitor. So to reverse them (as is advantageous when tumble washing), all the control needs to do is to switch the wiring connections. For a single phase motor, you'd probably need two starting circuits. Additionally, the starting circuit is not as efficient as three phase startup, so the motor would be operating at lower efficiency most of the time.
That is very true-you cannot use a 3ph motor on a single or two ph line without some sort of conversion-rotoverter,solid state converter.The converters make up the missing "phase".also the 3 phase motor could be run from the open delta three phase from 2 ph using the dist transformers.You can reverse single phase split phase motors by reversing the start winding.Many motors allow you to do this-usually instructions are in the motors wiring-capacitor box.If the start winding is wired like that by the factory in the motor-a reversing switch or relay can be used to reverse the motor.Then perfect for FL washers agitate cycles.No tangling!!
And here we have three-phase incoming service...
Junior *AHEM* pay attention...
three fused HOTS
Black
Red
Blue
and the white/neutral which is ALWAYS unswitched and uninterrupted, from meter to load.
The white/neutral is customarily grounded (earthed=> UK) at or near the meter.
(These are called cartridge-type fuses; they have "blades" at or above 60 amps capacity.)
Junior *AHEM* pay attention...
three fused HOTS
Black
Red
Blue
and the white/neutral which is ALWAYS unswitched and uninterrupted, from meter to load.
The white/neutral is customarily grounded (earthed=> UK) at or near the meter.
(These are called cartridge-type fuses; they have "blades" at or above 60 amps capacity.)
3- phase circuit-protection.
This is a circuit breaker panel box (consumer unit => UK)
that handles 3-phase power.
Note the breaker on the left that fits into three "slots" with a physically connected/joined handle (called common-trip). It has a blue wire going into it. This is the breaker for a 3-phase load (or a sub-panel).
The three leads feeding this box appear to be at the bottom.
[Yes, this wiring and this building is a S---hole, even by NYC standards. It is certainly not the beautiful panel Mr. X has posted, now is it....]
Jamie, I had to step in raw sewage to get this shot.
But you are off the hook..I needed it for work, anyway. LOL
This is a circuit breaker panel box (consumer unit => UK)
that handles 3-phase power.
Note the breaker on the left that fits into three "slots" with a physically connected/joined handle (called common-trip). It has a blue wire going into it. This is the breaker for a 3-phase load (or a sub-panel).
The three leads feeding this box appear to be at the bottom.
[Yes, this wiring and this building is a S---hole, even by NYC standards. It is certainly not the beautiful panel Mr. X has posted, now is it....]
Jamie, I had to step in raw sewage to get this shot.
But you are off the hook..I needed it for work, anyway. LOL
Jamie:
The cable seen above was (until recently) the only type allowed in NYC. it is called "BX" It is metal-sheathed cable (armored). This also provides the benefit of being mouse and rat proof, and shielding the occupants from stray magnetic fields that are generated when current passes through a wire.
The WHITE cables in your panel (shot #3) are plastic-sheathed and called ROMEX usually.
Grounding in BX is automatic via the outer metal covering; all junction boxes and switch/receptacle (power-point=> UK) boxes MUST be metal.
WIth ROMEX (plastic-sheathed) cable grounding takes place via a bare copper conductor; a conscious effort must be made to join all such grounding conductors. When metal boxes are used they also must be grounded.
TA TA FOR NOW.
The cable seen above was (until recently) the only type allowed in NYC. it is called "BX" It is metal-sheathed cable (armored). This also provides the benefit of being mouse and rat proof, and shielding the occupants from stray magnetic fields that are generated when current passes through a wire.
The WHITE cables in your panel (shot #3) are plastic-sheathed and called ROMEX usually.
Grounding in BX is automatic via the outer metal covering; all junction boxes and switch/receptacle (power-point=> UK) boxes MUST be metal.
WIth ROMEX (plastic-sheathed) cable grounding takes place via a bare copper conductor; a conscious effort must be made to join all such grounding conductors. When metal boxes are used they also must be grounded.
TA TA FOR NOW.
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