| I have been using submersible pumps for my 45 tons pond as the main filtration pump since 1999. I have not had an incident where my koi is electrocuted. The pump will fail after one to three years of operation depending on the manufacturer, some last longer than others. The nature of failure I encountered are 1) Open circuit in magnetic coil. The pump just stop running, electric circuit intact, no tripping. 2) Pump seal leakage, water ingress into magnetic coil cause current leakage. In this situation the Earth Leakage Circuit Breaker in my main distribution board would trip until the pump is switched off.
All submersible pumps that I have used are filled with turbine oil and I have never encountered any oil leakage in the event of pump failure. I could be lucky though.
My pump is located inside filtration chamber. But I have seen many ponds converted from water garden pond where there is no bottom drains. The submersible pump would be sunk inside the pond itself. From my observation the koi do swim around the sub pump and not avoiding it. Therefore I conclude that the koi do not seemed to be adversely affected by the sub pump. |