I am reviewing a set of drawings where the EE has used an undersized neutral to feed an MCC. The phase conductors are 300MCM, the neutral is #4. The only loads connected to the neutral are control transformers 347-120V. The conductors are all to run in a single conduit along with a #3/0 EGC and are protected by a 300A CB.
The Canadian Electrical Code allows the neutral to be sized to carry only the unbalanced load, so I am not concerned about code compliance. I would like to know what you think about installing an undeersized neutral. Are there safety issues, have you had experiences with faults in such installations?
