Today at ~11:10 am, IP3 (LVEA 2x 1250 l/s IP) failed leading to a slight pressure rise in the corner. Seen on all LVEA pressure gauges (BSC2, HAM6, etc.). Attached snapshot shows the two pumps behavior at the time of failure, pump ion current on left column, output voltage on right.
Gerardo and I went to the mechanical room to diagnose the controller, upon arrival both channels on the Dual Vac controller had tripped off. We reset the high voltage and powered on the IP. Channel 1 (corresponding to Pump A in CDS) would only reach 300 V and then would trip the controller. Channel 2 (Pump B would reach 7kV no issue but would trip when Channel 1 tripped). We then swapped to a Gamma MPC controller to test if the controller was the problem. We saw the same exact behavior where Pump A would only reach 300V and Pump B was ok at 7kV.
We then swapped back to the DualVac controller after confirming it was not the issue, but with only Pump B connected and powered on. We are continuing to monitor to make sure Pump B remains steady. In parallel, Travis and Mark are testing the HV cable to the pump to see if there are any shorts. Results to follow.
If the cable is not the culprit we will HiPot the pump to see if there are any shorts, pump will be isolated from main volume during this test. To be continued.
Using the Agilent FieldFox N9912A we measured the cable length with the following parameters:
Mode = DTF (VSWR), F_Start = 2.0MHz, F_Stop = 450.0MHz, Points 801, Resolution 261mm
Start Distance 5.0m, Stop Distance 170.0m
The cable end was detected at 80.79m from the start of the launch cable, launch cable was about 1m.
The cable measurement was similar to the other cables measured.
When measured with the DMM, this cable measured open, but when the connector was moved, it displayed ~6M ohms, this would normally not be an issue, but due to the high voltage in this location it may be an issue, recommend hipot.
M. Pirello, F. Clara, G. Morenao, T. Sadecki, J. Vanosky
Problem solved, see in aLog 84826