Using three phase MCCB for singel phase lighting circuits.
Using three phase MCCB for singel phase lighting circuits.
(OP)
I have some lighting circuits connected to a three phase system. For normal running, three phases will be used for lightings. When the normal supply is not available, the generator kicks in but it will onyl be able to supply one phase of the lighting instead of three phases. This is done through a switch.
However I am only using one three phase MCCB at the distribution board. Will there be any problems in supplying single phase circuits with three phase MCCB?
However I am only using one three phase MCCB at the distribution board. Will there be any problems in supplying single phase circuits with three phase MCCB?






RE: Using three phase MCCB for singel phase lighting circuits.
That said, this situation is so unusual that I seriously doubt it is covered in any electric installation codes. So if inspectors in your country are anything like those here in the US, they have the ultimate authority and can reject anything they are not comfortable with, especially if it is not covered by regulations. That part where I said "...and any future user..." is a potential sticky point in my opinion.
By the way, some newer electronic trip circuit breakers have built-in phase loss protection that may get in the way. Under Voltage Trip coils would be a problem as well. Another potential pitfall is if the breaker has a shunt trip coil for fire shutdown, you would want to make sure the shunt trip coil power is coming off of the generated phase.
RE: Using three phase MCCB for singel phase lighting circuits.
I sounds like you have 3 single phase loads connected to 3 single phase conductors A,B and C. Therefore the generator will be supplying a single phase voltage to the lights. I am having a problem with how you will connect the 3 circuits to the single phase conductor from the generator. If the loads are all on the same phase normally, then no problem.
RE: Using three phase MCCB for singel phase lighting circuits.
RE: Using three phase MCCB for singel phase lighting circuits.
Can the three phase MCCB at board A be used for this application?
RE: Using three phase MCCB for singel phase lighting circuits.
You may have issues with a newer electronic trip breaker as noted by jraef. If the generator is supplying lighting only, you may be able to install the transfer switch after the MCCB.
respectfully
RE: Using three phase MCCB for singel phase lighting circuits.