Ross Mackay Forum Moderator 93 Posts
Re: What's Causing The Pump To Trip?21 November 2008 at 1:29pm
The first question that leaps to my mind is “what happened in June of 2008 to cause this tripping problem?” You are right in thinking that, since it started at a specific time, some parameter has changed. However, it could easily be the design or the layout. I would focus on that question.
The trick here is to be relentless in your investigation. When people tell you that nothing has changed, they often mean that what has changed is something that they think has no relation to the problem. They could be wrong.
I would also check the “upset conditions.” Have they changed? Has something happened to cause the system curve to flatten out, thus requiring all three pumps to operate at a much lower head? I’m assuming that we’re talking about centrifugal pumps in parallel and that it is the standby pump motor that is tripping out due to an overload condition.
Remember if no one has changed anything about the pump in June 2008, then the pump is not the problem. The centrifugal pump is a slave to the system, so we must look to the system for the problem.