Reports until 16:09, Tuesday 26 July 2016
H1 SEI
hugh.radkins@LIGO.ORG - posted 16:09, Tuesday 26 July 2016 - last comment - 21:38, Tuesday 26 July 2016(28653)
EndX HEPI Pump Servo Shutdown with OverVoltage Error

JimW, JeffK, HughR

Around 1900 utc, the pressure dropped and the servo drive went to max; from afar, this looks like a fluid level trip.  Jeff went to the end station and found that the front panel red light was still on indicating it was not a fluid level trip.  Opening the controller panel to access the VFD revealed the OU3 error indicator.  Last aLog with this problem found with quick search was at EndY July 2015.  Maybe it is a warmer weather problem.  Brought control servo output to 0, reset VFD to clear the error and then brought things back under servo control, around 2200utc.  Jeff noted the fluid levels were same as before--no fluid problems.

Comments related to this report
jeffrey.kissel@LIGO.ORG - 16:25, Tuesday 26 July 2016 (28654)
Link 

Pictures from the investigation attached.

First: The front of the fluid level indicator of the HEPI pump fluid reservoir.

Second: The "iso" view of the fluid level indicator, showing that the fluid level with the pump servo OFF (or "stopped" or tripped like it was when we found itp) is at 9 2/16 inches, which matches the level in early June when the level was last checked without the pump running.

Third: a look inside the Variable Frequency Driver (VFD) enclosure taking a picture of the VPD while in its "OU3" (for Output Voltage 3) error. The "reset" button to which Hugh refers is in the bottom left corner.
Images attached to this comment
john.worden@LIGO.ORG - 21:38, Tuesday 26 July 2016 (28665)
Link

According to the manual OU3 is an "over voltage error while at constant speed". - see attached page.

Other VFDs on site have similar issues which we think is due to spikes on the 3 phase supply. 

Richard can tell you more.

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