Transcript MP3-Main-Issues-29-03-2010_mzx

MP3 List of main Issues
during 22-28 March 2010
MP3 - Team
Main issues on previous week
Circuit
Problem
Intervention
on field
Remarks
RB.A12
(22 March)
Communication lost on one main dipole magnet
YES
RB circuit safe if I<2000A, but for higher energy, the
heater power supplies must be charged.
NO
Wrong FGC parameters for slow abort and zero
voltage crossing
dI/dt (RU.L4) < 0.3A/s, dI/dt (RU.R4) < 0.08A/s
if I < 50A, U_res threshold = 2V
if I > 50A, U_res threshold = 100mV
RU.L4 / RU.R4
Many trips during controlled ramp down, even
(22,23,24 March) when using ‘correct’ di/dt
RQTD/RQTF
(23, 25 March)
Tripped several times because of too fast
trimming correction or wrong seqeunce when
disabling the tune feedback.
Tripped several times. Why?
NO
NO
5th trip for RCO and 4th trip for RCD in 6 days. In all
5 events RCO goes first.
RB.A23
(27 March)
Discharging Heater Power supply on MB.B20R2
YES
Fault on front-panel connector
IT
(27, 28 March)
Inner triplet circuits trip frequently when being
stopped with a Slow Power Abort
NO
ROF.A45B2
(28 March)
Tripped during pre-cycle without apparent
indication of a fault in the converter
tbc
Needs detailed analysis by EPC expert, probably
related to not synchronized sequence of switching
OFF nested converters
Fault is most likely related to the AC contactor state
contact, might need EPC intervention, tbc
RB.A45
(28 March)
Blocked nQPS crate in B33R4 during beam
injection
NO
Reset of crate solved problem, but beam had to be
dumped and sector switched off
RQX.R2
(28 March)
Trip of main triplet circuit at injection level
NO
No apparent reason for trip (no signal above
threshold), but ‘noisy’ Q2 signals, tbc by QPS expert
RCO.A56B2
(22,24, 25,26)
MP3 Team
Main issues on previous week
Circuit
Problem
Intervention
on field
Remarks
RB.A12
(22 March)
Communication lost on one main dipole magnet
YES
RB circuit safe if I<2000A, but for higher energy, the
heater power supplies must be charged.
NO
Wrong FGC parameters for slow abort and zero
voltage crossing
dI/dt (RU.L4) < 0.3A/s, dI/dt (RU.R4) < 0.08A/s
if I < 50A, U_res threshold = 2V
if I > 50A, U_res threshold = 100mV
RU.L4 / RU.R4
Many trips during controlled ramp down, even
(22,23,24 March) when using ‘correct’ di/dt
RQTD/RQTF
(23, 25 March)
Tripped several times because of too fast
trimming correction or wrong sequence when
disabling the tune feedback.
Tripped several times. Why?
NO
NO
5th trip for RCO and 4th trip for RCD in 6 days. In all
5 events RCO goes first.
RB.A23
(27 March)
Discharging Heater Power supply on MB.B20R2
YES
Fault on front-panel connector
IT
(27, 28 March)
Inner triplet circuits trip frequently when being
stopped with a Slow Power Abort
NO
ROF.A45B2
(28 March)
Tripped during pre-cycle without apparent
indication of a fault in the converter
tbc
Needs detailed analysis by EPC expert, probably
related to not synchronized sequence of switching
OFF nested converters
Fault is most likely related to the AC contactor state
contact, might need EPC intervention, tbc
RB.A45
(28 March)
Blocked nQPS crate in B33R4 during beam
injection
NO
Reset of crate solved problem, but beam had to be
dumped and sector switched off
RQX.R2
(28 March)
2 trips of main triplet circuit at injection level
NO
No apparent reason for trip (no signal above
threshold), but ‘noisy’ Q2 signals, tbc by QPS expert
RCO.A56B2
(22,24, 25,26)
MP3 Team
RQX.R2
• RQX.R2 tripped twice while at injection current (450A)
–
–
–
No magnet quench at this low current
Heaters fired in both events (21:46 and 01:32), without clear indication as to the source
of the (QPS) trigger
No apparent fault of the power converter
MP3 Team
RU.L4
• RU.L4 still show frequent trips during controlled ramp downs
– Problem related to incorrect ramp rate solved (now 0.3A/s)
– Seems zero-voltage crossing problem, as QPS threshold will be raised
when <50A, propose to align ramp rate with RU.R4, ie 0.08A/s to
delay zero voltage crossing into <50A region
MP3 Team
RQTD/RQTF
Resistance of 2 Ω in parallel on the circuit
• Note for operators : 600A detectors must be properly reset before restarting the machine
• Frequent problems due to teething problems with tune feedback
–
Procedures and sequence fixed during the week
MP3 Team
RCO.A56B2 + ROF.A45B2 + IT
•
•
•
ROF.A45B2 tripped with a fault which seems related to the AC contactor
state contact -> might need an intervention to replace the power module
(tbc by EPC) -> Currently not vital for beam operation
RCO.A56B2 and RCD.A56B2: 5th trip for RCO and 4th trip for RCD in 6 days.
In all 5 events RCO goes first, all events seem triggered by U_RES jumping
to 250 mV in a step function (needs detailed analysis with EPC and QPS) ->
Currently not vital for beam operation
IT in general: Repetitive trips when switching them OFF or after Slow Power
Aborts -> needs to be analysed by EPC, rather important as > pre-cycles
MP3 Team