D
daveelectrician
I am currently on quite a big CCTV installation in a new power station.
The original job was to install 2 locally fed DBS fed from 2 new centre tapped 110v transformers to free up ways on the 110v DBS adjacent and supply some of our cameras ( with incorporated heater), the other cameras were to be fed from DBS which are local. The install is now complete and one of the electrical bosses had came to inspect the job,straight away he has said I can't feed the cameras from the DBS as they are centre tapped for the sockets and equipment can't be fed from these transformers. I have had to strip out my other swa's and feed them from my new DBS through a step down transformer.
Does anybody know why equipment can't be fed from centre tapped transformers? Forgot to say that cameras are 24v so need to convert 110v to that voltage at the cameras.
Another question is with my original transformer, I was going to put positive on the brown phase and negative on the black using double pole mcbs, now that I am using a step down do I still terminate my DBS this way or do I terminate it as per usual 3phase DBS with single phasing kit using single pole mcbs?
The original job was to install 2 locally fed DBS fed from 2 new centre tapped 110v transformers to free up ways on the 110v DBS adjacent and supply some of our cameras ( with incorporated heater), the other cameras were to be fed from DBS which are local. The install is now complete and one of the electrical bosses had came to inspect the job,straight away he has said I can't feed the cameras from the DBS as they are centre tapped for the sockets and equipment can't be fed from these transformers. I have had to strip out my other swa's and feed them from my new DBS through a step down transformer.
Does anybody know why equipment can't be fed from centre tapped transformers? Forgot to say that cameras are 24v so need to convert 110v to that voltage at the cameras.
Another question is with my original transformer, I was going to put positive on the brown phase and negative on the black using double pole mcbs, now that I am using a step down do I still terminate my DBS this way or do I terminate it as per usual 3phase DBS with single phasing kit using single pole mcbs?