Displaying report 1-1 of 1.
Reports until 06:41, Thursday 14 February 2019
H1 PSL (PSL)
peter.king@LIGO.ORG - posted 06:41, Thursday 14 February 2019 - last comment - 07:25, Thursday 14 February 2019(46941)
Reference cavity alignment tweak
Tweaked alignment into the reference cavity.

    When I exited the enclosure, as soon as the air shower door closed, all HEPA fans and the make up air fan died
and the controller indicated that the air conditioning units were off.

    An observation I have noticed is that with the change made to the air conditioning set temperature, the heater
drive for the pre-modecleaner behaves quite differently - most likely because it no longers sits as high above
ambient temperature as it once did.  As a result it limits the time that can be spent in the enclosure to about
half an hour before a dance between the pre-modecleaner losing lock and the reference cavity losing lock.  As the
FSS is trying to re-acquire, the pre-modecleaner PZT voltage heads towards the low end causing a delay as to
when the FSS re-acquires because the pre-modecleaner drops out of lock.  All of which makes re-alignment an exercise
in patience.
Comments related to this report
peter.king@LIGO.ORG - 07:21, Thursday 14 February 2019 (46942)
After getting the FSS to lock, I went back outside to the LVEA to find that all the HEPA fans and
air conditioning units were now on.  They were switched off.  There's something not quite right
with the controller panel at the moment - for what ever reason.
Images attached to this comment
peter.king@LIGO.ORG - 07:25, Thursday 14 February 2019 (46943)
I've turned the make up air fan to 100% to aid bring the temperature down a little faster.

    The make up air fan was turned off at ~08:30 am.
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