zog
Senior Member
- Location
- Charlotte, NC
I hope this is not too far off subject but will chance it. I do not condone this procedure for breaker trip testing since I come from a long line of breaker testing using the low voltage-high current testing procedures, but experienced this about 14 yrs ago.
While I was doing start-up testing on the AirTrain people mover project at SFO airport I was shocked (pardon pun) to hear of the procedure that Bombardier Transportation (formally Westinghouse Transportation) was required to use to test the trip units of the Eaton DS air frame CB in the 5 double-ended substations. I think the breaker frame sizes were in the 800A range. They would clamp copper shunts (dead shorts) using vice-grip pliers across the 600V conductor rail segments that the cars were powered from. Then on a remote command from central control wound send a close command to the breaker ...and....BOOM!!! the breaker would trip!!!! We would stand behind a transformer (chicken, I guess!) to witness to operation and record the results. Yeah, never heard of this before but it was a real world way of verifying the trip unit, cable and bus connections of each circuit during a real fault condition. The breaker contacts were inspected afterwards but did not find any problems since they are designed for this.
Has anyone ever experienced this type of testing?
Yes, I have witnessed many HEFA tests at power labs of large air frame breakers. Pretty cool stuff.