Today we were measuring voltages on the secondary of a 480V/277V transformer and saw that one of the L-G readings was 268V which seemed a bit low. All other L-G were about 277V and all L-L readings were 480V.
Should we be concerned with this low reading? What would cause this one reading to be low?
Transformer secondary has EGC going to enclosure, but does not have grouding electrode conductor (GEC) from transfomer to ground grid. Is this GEC required? I always thought is was required by code for SDS's?
Should this absence of the GEC make a difference on voltage readings by leaving the neutral floating? Even with the neutral not tied to ground, I always though that we should still read 277V between L-G since we are reading from hot leg to the neutral point weather it was grounded or not. Could this reading be b/c neutral is not tied to ground?
Should we be concerned with this low reading? What would cause this one reading to be low?
Transformer secondary has EGC going to enclosure, but does not have grouding electrode conductor (GEC) from transfomer to ground grid. Is this GEC required? I always thought is was required by code for SDS's?
Should this absence of the GEC make a difference on voltage readings by leaving the neutral floating? Even with the neutral not tied to ground, I always though that we should still read 277V between L-G since we are reading from hot leg to the neutral point weather it was grounded or not. Could this reading be b/c neutral is not tied to ground?