larrybartowski
Member
I'm working on the 13.8kv main switchgear of a large hospital. There are 13.8kv to 120v control transformer's with 1 amp primary fuses (for the 120v controls on the board) that have failed multiple times over the past year.
I've gathered information off of the power quality meter on each of the 13.8kv branch breakers within the switchgear and they are consistently reporting "negative sequencing". I'm not an engineer, so this is new to me. 2 Questions:
1. Is it safe to assume that because all of the 13.8 branch breakers are reading similar voltage imbalances, that this is a utility issue? Or is possible something downstream of the main switchgear could cause this?
2. What are some potential causes of consistent utility voltage imbalances?
I've gathered information off of the power quality meter on each of the 13.8kv branch breakers within the switchgear and they are consistently reporting "negative sequencing". I'm not an engineer, so this is new to me. 2 Questions:
1. Is it safe to assume that because all of the 13.8 branch breakers are reading similar voltage imbalances, that this is a utility issue? Or is possible something downstream of the main switchgear could cause this?
2. What are some potential causes of consistent utility voltage imbalances?