As Augie stated 240 volts phase to phase, 208 volts {120 * √3} high leg to ground or to the neutral.
how useful is 208v L-N?
About as useful as single phase when connected L-L. Problem is you will not find a single pole circuit breaker rated for more than 120 volts unless you get into the 277/480 series breakers.
Yes, I agree. My point was how useful is 208v L-N?
But you can use a 2-pole 240V L-G rated breaker (which are not that hard to order) and get the valid L-N voltage of 208V.
The problem isn't getting the voltage, it is what happens when you use it. Most 2-transformer, open-delta, banks were not sized with this loading in mind.
About as useful as single phase when connected L-L. Problem is you will not find a single pole circuit breaker rated for more than 120 volts unless you get into the 277/480 series breakers.
In my past expereince, it generally means some one gets a new drill.
Or a new vacuum cleaner, or a new vending machine, or a new alarm system.In my past expereince, it generally means some one gets a new drill.
Or a new vacuum cleaner, or a new vending machine, or a new alarm system.
As far as I'm concerned, this is one configuration I wish was never offered.
I know it may be more efficient for serving Motor Loads or the like, but I would offer 208/120v or 480v.
Theres still (1) Service in our small town on a Community Hall that is 240v Delta, all the rest have been
done away with, and I can't wait until this one bites the dust also.
Where there is an existing 240/120 3ph4w system it's a mater of what it will take to change to a 208Y120 3ph4w system.
As far as a new system goes I don't think the delta with a lighting tap is that popular to a new installatin anymore.
Come to rural areas, and farms, there is a lot of delta systems around. There are advantages and disadvantages of both wye and delta systems, especially in the 120-208/240 voltage range. 480 volts is always 277/480 Y unless there is not all three phases or is a limited load and it is supplied by open delta configuration to save on costs on the primary side of things. If running to a remote area it costs extra $$ to run the extra conductor to get a wye when an open delta will get the job done. And it definitely is better than having a single phase service and a phase converter in most cases.It's not that common as you've said.
And also I have had more then one establishment where the power company has changed over the existing
services from 240/120 3ph 4w system to 208/120v 3ph Y on a Service Upgrade,and the number of single
pole spaces that now become usable that were once a "Space Only" is quite nice.
The biggest kicker is if someone does'nt go in and relabel the voltage on all of the panelboards to
read, 208/120 3ph 4w, it gives the appearance of still being 240/120 3ph 4w at first glance.
Come to rural areas, and farms, there is a lot of delta systems around. There are advantages and disadvantages of both wye and delta systems, especially in the 120-208/240 voltage range. 480 volts is always 277/480 Y unless there is not all three phases or is a limited load and it is supplied by open delta configuration to save on costs on the primary side of things. If running to a remote area it costs extra $$ to run the extra conductor to get a wye when an open delta will get the job done. And it definitely is better than having a single phase service and a phase converter in most cases.