D. Wang reports that recently the overhead crane has been exhibiting a delayed start (approx. 1 min) when operating in local mode. This issue applies to the main hoist's up/down functionality only and does not seem to apply to other motion axes. T. Kauss briefly investigated but did not find any obvious cause.

This issue will be monitored and investigated over the following weeks and this log will be updated as more information becomes available.

Suggested troubleshooting steps:

• Isolate the issue to local or remote mode to confirm this suspicion (it appears to be present in both local and remote mode)
• With help from someone locally operating the crane, confirm at the receiver in the control room whether signals are coming through for up/down commands immediately, or whether the receipt of signals itself is delayed. At the same time, confirm whether the PLC input card is receiving the command signals from the receiver immediately or in a delayed manner. (it appears that the command signals are being received by the VFDs - the issue seems to be on the output side)
• Time the delay, and repeat to confirm if the timing is consistent every time as reported by D. Wang (it appears timing is inconsistent. After a weekend of no use, it was approximately 2 minutes. After a few hours of no use, it was around 10 seconds).
• Check if delay is present across various crane positions in the target hall (completed by D. Wang - result: yes)
• Inspect controls hardware in the cabinet in the control room, as well as the remote IO on top of the crane, for obvious issues (checked cabinet but not remote IO - nothing obvious)
• Go online with the PLC and test up/down commands to see if the program indicates any obvious issues (note: this may not actually help - seems to be an electrical issue isolated to the VFD-related electronics)
• Mechanical inspection of the motor (not likely an issue)
• Disconnect motor, repeat test of trying to command up/down motion and see if the motor itself had any effect on the delay

Update, 2024-09-09 [DW]:  Confirmed both local and remote mode have the same problem on delayed main hoist functional issue after crane was switched on. The delay time is 1 minutes 40 seconds to 2 minutes. It happens mostly when first time the crane was switched on. But if the crane was not used in the rest of day after first time switching on , the problem showed again 5 to 6 hours after in same day.

Update, 2024-09-09 [AN]: Checked again around 11:30am... tested running both hoists A and B in remote mode. Upon first attempt to lower hoist, no motion occurred. Hoist A VFD exhibited fault code 51, and Hoist B exhibited fault code 52. Both hoists appeared to receive the command from the PLC to attempt to move. Both hoists (initially) had their "ready" status as ON. When attempting to move, however, hoist B's ready status dropped out. Note also that the delay observed between the failed attempt to start, and when motion was actually possible, was only approximately 10-20 seconds. Perhaps this correlates to the fact the crane was recently operated this morning. It is suspected that the charging circuit for hoist B's DC bus voltage is faulty.
Tomorrow, another test will be performed by checking A and B independently to see if one can run but the other cannot.

Update, 2024-09-10 [AN]: Tested the crane using only Hoist A: working upon first power-up of the day. Tested using only Hoist B: not working, fault 52 re-appears. We are certain the issue lies with Hoist B. Furthermore, upon observing the motor contactors and status LEDs when attempting to energize the motor, the following is observed:

• For Hoist A (normal, working operation) - on power up K1 toggles on (in). When pressing down button, K7 toggles (in). The hoist begins to move.
• For Hoist B (non-functioning), on power up K1 toggles on (in). When pressing down button, K7 does NOT toggle. K1 toggles OFF (it should not) then comes back, then triggers the fault.

Upon further inspection it was noted that for K1 for Hoist B, there appears to be a snubber (XEB2202) wired in across the A1 and A2 terminals of the contactor. The fact that a time-dependent circuit is involved matches earlier theories about a charge-timing related issue. Suggested action: attempt to remove the snubber and test again to determine if the issue persists.

Update, 2024-09-11 [AN]: Under work permit I2024-09-10--3, the following was tested and observed:

• Run Hoist B to confirm it is not working (expected behaviour) - confirmed
• Power off crane, remove the snubber from Hoist B's contactor K1
• Power on crane, attempt to run Hoist B - the hoist did not run
• It was noticed also that Hoist A did in fact have a snubber installed as well - it was hidden. The snubber for Hoist B's capacitance was measured and confirmed to match what it should be, so it is suspected that it is working fine.
• This indicates that the snubber is not the issue. The snubber was reinstalled and the system returned back to normal state. Tested - working.

At this time the root cause remains unknown, but the snubber has been eliminated from the possibilities.

It appears that the issue can be isolated to the fact that contactor K1 momentary toggles off when attempting to operate the hoist. This short blip would explain the fault code related to insufficient line voltage. The drawings indicate the only way that K1 can turn off is if the 48 VAC supply from the transformer drops out momentarily, or if an unnamed relay located (presumably) in the VFD momentary toggles.

Further troubleshooting steps could include:

• Probe for 48VAC at A2 terminal of K1 and attempt to operate the hoist - see if it drops off briefly. If so, the issue is either the transformer or the relay contact in the VFD. Perform continuity check across the relay contact, repeat attempt to operate hoist, and determine if it is the relay contact causing the issue. This test will significantly isolate the issue.
• Check inside Hoist B's VFD circuitry and measure the DC bus voltage during attempted operation, and compare to Hoist A. There may be an issue with the charging circuit inside the inverter.

Update, 2024-09-13 [AN]: Under work permit I2024-09-10--3, the following was tested and observed:

• Probe the A2 terminal of K1 for Hoist B with respect to the transformer's 0V output upon initial power-up of the system: ~53VAC measured (should be 48VAC but 53 is acceptable)... this confirms that the appropriate relay coil voltage is present upon power-on, as expected because it is observed that the relay toggles upon power-up.
• Continue probing A2 while attempting to jog Hoist B down, with min-hold set on the multimeter to check for voltage drops: the voltage measured was approximately 24VAC during one attempt and 36VAC during another. This implies that K1's coil voltage does in fact drop out instantaneously, resulting in K1 very briefly disengaging which causes the observed VFD vault. The fact that the measured min voltage is different can be attributed to the mulitmeter's sampling rate, catching the voltage during its decline towards 0.
• Because of the aforementioned test results, it is confirmed that there is an issue associated with K1's coil voltage briefly dropping out when attempting to run the hoist. There are only two reasons this could happen: 1) the transformer power output of 48VAC actually drops, or 2) the relay contact in series with this (located inside the VFD) opens up as a result of a VFD fault. The latter is more likely.
• Upon investigating the VFD further, it was determined that another fault code was present prior to the above mentioned code 52. This fault code happened very briefly at the same time as K1 toggling, but was then covered up by code 52. This fault code is 2, which states that there's an overvoltage condition - the DC bus voltage has exceeded 911 VDC (135% of device maximum nominal voltage of 500V). This can be attributed to a supply voltage surge in which it is raised 35% above its nominal value.
• Note: line-to-line voltages were measured at the input to K1 after the "warm up period" and the issue was resolved, when the hoist was sitting idle. These were measured to be almost exactly 480VAC. This represents a reference condition.
• What seems to be happening is that when the hoist motion attempts to start, there is a line voltage surge for some reason (back-emf?) which causes this fault condition for a temporary instant, but then when the voltage dissipates the fault instantly clears. This explains why contactor K1 very briefly flickers during motion attempt - the fault is only briefly present. But then, fault code 52 takes over and remains present (because of the line voltage disruption).
• Still, the root case of this issue is unknown. It is not confirmed whether there is actually a voltage surge or not (to be measured next week), and why it seems to only happen for the first ~2 minutes of the day.
  It could be attributed to one of the following reasons:
  • Coil voltage rectifying diode partial failure inside K1... the diode may need time to "warm up"
  • Brake solenoid partial failure for Hoist B (causing additional friction which leads to overvoltage condition for the motor)... the brake may need time to "warm up"
  • Charging capacitor issue in DC bus voltage charge circuit inside the VFD

Suggested troubleshooting steps:

• Probe line-to-line voltage at input terminals to K1 during attempt to operate Hoist B in max-hold mode: check for surge, record values
• Probe DC bus voltage during the same condition, record value
• Determine if the above indicate a true overvoltage condition, and determine why this may be

Update, 2024-09-16 [AN]: Under work permit I2024-09-10--3, the following was tested and observed:

• Probe L1-L2, L2-L3, and L1-L3 line voltages on input side of contactor K1 for Hoist B with max hold set on multimeter to confirm whether there is a surge when attempting to move the hoist - no surge was observed. 480VAC constant was measured in each case.
• There may be another issue causing the DC bus overvoltage condition (an issue with the motor or an issue with the drive itself)

Suggested troubleshooting steps:

• Probe DC bus voltage during the faulted condition, record value
• Disconnect the motor from the drive and check motor winding resistances before and after the "warm up" period to see if there is a change, and also compared to Hoist A
• With the motor disconnected, attempt to run the drive - determine if fault code 2 shows up or if the drive appears to be working.. this may eliminate the motor from the list of potential issues

 Update, 2024-09-16 [AN]: Under work permit I2024-09-16--3, the following was tested and observed:

• Probed DC bus voltage on Hoist B's VFD prior to attempting to move hoist, and during the attempt to move it. In both cases it remained a constant 690 VDC. No temporary spike was observed. This is also lower than the threshold that the VFD's manual stated the fault would typically occur at (~911 V) so it casts doubt on whether this is the root cause of the problem.
• Probed DC bus voltage for Hoist A's VFD, for comparison - same measurement.

Suggested troubleshooting steps:

• Disconnect the motor from the drive and check motor winding resistances before and after the "warm up" period to see if there is a change, and also compared to Hoist A
• With the motor disconnected, attempt to run the drive - determine if fault code 2 shows up or if the drive appears to be working.. this may eliminate the motor from the list of potential issues
• Swap VFDs between Hoist A and B to determine if the problem tracks the drive
• Swap K1 between Hoist A and B

Update, 2024-09-16 [AN]: Under work permit I2024-09-16--3, the following was tested and observed:

• Measured motor winding resistance between every combination of lines for both Hoist A and B (for comparison). Note: this was done mid-day, prior to any use of the crane for the day. In each case, the resistance was measured to be 2.2 Ohms. There is no difference between the A and B. This is not likely the root cause of the issue.

Suggested troubleshooting steps:

• With the motor disconnected, attempt to run the drive - determine if fault code 2 shows up or if the drive appears to be working.. this may eliminate the motor from the list of potential issues
• Swap VFDs between Hoist A and B to determine if the problem tracks the drive
• Swap K1 between Hoist A and B

Update after email discussion with Kone service tech, 2024-09-23 [AN]:

The Kone service tech said "This is a obsolete inverter and there is not a direct replacement available or parts for repair .  It is recommended to replace inverter with a conversion panel. The conversion panel consists of new, correctly sized components including D2V inverter, to have the same functionality as original panel. All components mounted and prewired to a back panel that fits directly inside the existing enclosure. All inputs and outputs are terminated at a terminal strip. Interconnecting wiring diagrams are also provided for ease of installation. The lead time for a conversion panel is approximately 10-12 weeks after receipt of a Purchase order."

A quote will be obtained from Kone for the replacement.

Update after K7 swapping between hoist A and B with Jason, Mike, Julie, 2024-10-09 [DW]:

Contactor K7 was swapped between hoist A and B. On hoist B we saw F52 fault and K7 did not engage in properly. On hoist A we saw F51 fault which is "stop limit has be tripped" and K7 also did not engage in properly. After 2 minute wait, both hoist A and B are back to normal. The plan for tomorrow: switch to A hoist and test. right after, switch to B and test. 
UPDATE FOR PAST THREE DAYS TESTS AND PROGRESS.  DAVID WANG 2024-10-12
2024-10-09 noon. Left crane with power on for 1 hour. switched off power on crane for rest of day to Thursday morning test.
2024-10-10 morning. Set to A hoist only. Switched on main power and tested hoist A down. It was normal, no delay. Right away switched to hoist B and tested hoist B down . It was normal, no delay. Switched to A and B and tested hoist up and down. It was normal, no delay.

2024-10-10 noon.  Replaced spark quenchers on hoist B K1 and K7. Tested crane after replacement. Everything works fine. Used crane to lift up F308 around 1:30. Then switched off crane for next morning test.

2024-10-11 morning. Set to A and B. Tested crane hoist down twice 2-3 seconds each time with 3 second between. No fault. Hoist worked fine.  3 second after, tested hoist up and found  K7s were not on on both A and B. 10 seconds after tested hoist up again and it worked. Then tested all crane movements. Everything was normal. Crane was used for spent target moves to 2:30pm . Then switched off.

2024-10-12 morning: Set to A and B.  Right after power on, tested hoist up for 5 seconds. wait 3 seconds, tested hoist down for 5 seconds. Repeated same up and down test within 3 seconds.  No fault. the hoist A and B works fine. Tested N-S,E-W movement. all good.  at the last, tested hoist up and down 10 seconds each. Hoist A and B are still good. The plan for next morning test: Leave crane power off to Tuesday morning and test hoist A+B(48 hours power off). Also plan to replace spark quenchers on hoist A /K1 and K7 if any delay is found on Tuesday morning test. 
2024-10-15 morning: Set to A and B. tested hoist up and down one click on each. I saw K7 momentarily "on" then drop off symptom as before. I saw F51 on A and F52 on B. Switched to A right away and tested. A works fine. Then switched to B and tested. B works fine. The total test time from A+B to B then to A is about 30 seconds. Then i switched back to A+B for checking. everything works fine as anticipated.

2024-10-16  A-K7 snubber was replaced yesterday after morning test . Tested hoist A+B this morning after 24 hours crane power off. Hoist A+B works fine on both up and down. 

2024-10-17 Tested A+B hoist this morning after 22 hours crane power off. Hoist A+B works fine on both up and down.

2024-10-18 Tested A+B hoist this morning after 24 hours crane power off. Hoist A+B works fine on both up and down.

2024-10-21 Tested A+B hoist this morning after 72 hours crane power off. The delay issue on hoist B appeared. Hoist A is fine. B/K7 was momentarily on then dropped off. By the same time B/K1 was momentarily dropped off then on with F52 code.

2024-10-22 Tested A+B hoist from target hall this morning after 22 hours crane power off.  hoist A+B  works fine on both up and down.

2024-10-22 noon.  Swapped  hoist A/K1 and B/K1. Crane power off at 9:30am after flask/pail repacking job.

2024-10-24. Tested A+B hoist this morning after 46 hours crane power off. Hoist A+B works fine on both up and down. Crane will be left as power off for 48 hours for next test.

2024-11-21. In the past month ,I tested crane multiple times. 24 hours power off test results are good always. 48 hours or longer power off test results are not consistent. Hoist B had 15 to20 seconds delay on early checks after last e -log. But in recent  6 days power off check and 3 days power off check, the hoist B has no delay. The next step: 1, keep on multiple days power off check. 2, replace Hoist B K1 (line+auxiliary) contactors with new parts.

2024-11-25. tested hoist A+B this morning after 4 days crane power off. No delay. everything works fine. Replacement contactors for K1 have been requested. Line contactor is in 5 weeks back order status from Digikey so we will replace Hoist B K1 next year in January mostly.

2024-12-02. Tested hoist A+B this morning after 4 days crane power off. No delay. everything works fine. It looks like  no delay status is stable now by watching on past 40days morning check result. Daily and multiple days check on hoist B  will be kept on.

2025-01-02. Tested hoist A+B this morning. The last time of crane using in 2024 should be 18th Dec. No delay . Crane works fine.

HALCW resin tank has been replaced. The old tank is stored in middle-west silo now. The field on old resin tank bottom is about 3.5 msv/ hr(on contact). By shielding it into silo and putting two lead blankets on the top cover of the silo,The general field 1 feet above this silo is 25usv/hr. And, The field around the silo area are less affected. This old tank will stay there as long as possible.  For the new resin tank during preparation, It was found that on return line side, the 1.25" pipe thread plug with return line tube  was very difficult to be installed onto the female thread adapter which is welded onto to tank body. It was jammed in half way of threading onto tank at manufacturer. This plug was removed out first and inspected. The first and second male threads were galled.  Maico repaired the thread on a lathe. The female thread on the tank was tapped. A tight spot was found during the tap. After that, the return line plug could be installed onto the tank properly.  The new tank was installed into the vessel and connected back to HALCW system. Water are refilled into new tank. During refill air were trapped into the system. This caused  pump restarting problem. By Several times of starting up the pump, stopping the pump and venting,  Most air were breathed out of  system. Finally,The system was restarted by supply water to ITW( without module) only. ITE and resin can circuits were brought back to system after that without problem.

 Before removing the old tank, We drained water out of old tank to decay tank. Since the resin tank is largely filled with  resin, and water are soaked into resin, we only can drain out less than 10 liters water out of tank. Also, The drain caused some part of return line on pumps have to been drained. This is the main reason air was trapped in system during the new resin tank water refilling. For the future replacement, we should not drain water in old tank. It does not worth to do it. 

Attach TH HALCW resin tank replacement procedure here.

2022-02-17 reload replacement procedure and draining schematic.

HALCW MP2 is switched onnow. There is a small amount of air trapped in system. The pump works fine.  Water level and system resistivity will be monitored for a while.

LALCW P5 and P6 are switched on  for cooling HALCW.  HALCW MP2 is in operation now.

HALCW MP2 is switched on this morning after yesterday cooling tower maintenance. LALCW P5 and P6 pumps are started by isac operator  as well. The system is good so far.

With both stations in operation,ITE dump supply gauge reading is 27 psi. ITW is 20 Psi.  I adjusted ITW dump pressure to 25 psi by changing the return line side pressure relieve valve.

ITE full operation+ ITW no TM: ITE dump pressure 27psi, ITW dump pressure 27psi.

2019-01-30: Water only supply to 2A beam lines only on both side, No TM2 and TM4 in water loop.  ITE dump pressure 27psi, ITW dump pressure 27psi.

High  active water pump is started. The system resistance is recovering now. Everything works fine so far. Check ITW and ITE water leak after pump is started. Tiny very slow seep on two small ball valves pack seal. No big concern.                                 

High active water are purged to holding tank at B2  level. There should be around 48 gallons are purged out of system. No purging on dump circuits on both ITW/ ITE.

Adrian and co installed a new T to be able to add an instrument loop for O2 and pH monitoring on the low conductivity water systtem (photo). See WP I2021-04-09-4

High active water system is refilled. Air are drained out of  system before pump to be started. Following sequence are used to bring the whole system back to operation:

1. close ITE , open ITW. Switch on the pump. Only 2A beam line related 5 water circuits are in loop in ITW.  Switch off pump when system pressure is stable above 100 psi.

2. Close ITW, open ITE. Switch on the pump. Only 2A beam line related 5 water circuits are in loop in ITE. Switch off pump when system pressure is stable above 100psi.

3. Open ITW, Open ITE. Switch on pump. both ITW and ITE beam line related water circuits are in loop.  Switch  off pump when system pressure is stable above 100psi.

4. Close ITE open ITW.  Bring ITW  target module water circuits back to loop by connecting bypass fittings on to circuits. Only bring one circuit back to system at first. Switch on pump. Wait for system pressure stabilized. Then Close ITW. bring next circuit back  to system.  Open ITW .  wait for pressure stabilized.  repeat the process until all water circuit and connected with bypass fittings in ITW.

5. Check possible leak on valves, fittings, and flow sensors in ITW pit.

6. Go to electrical room, check all ITW water signal status.

7. Close ITW, Open ITE. Repeat same procedure as step 4 on ITE target module water circuits.

8. Check possible leak on valves, fittings and flow sensors in ITE pit.

9. Go to electrical room, check all ITE water signal status.

10. Open ITW.  At this stage, full ITE station and half of ITW station water circuits are in operation.  Check possible leak on pumps, valves, fittings, gauges on water station at TH west end.

11. Keep system in operation. Watch on - tank level , system pressure, and conductivity on resin circuit and whole system.

 The valves #V10 & V11 beside high active water pumps were replaced in Target Hall, pics attached.

 A 3/8 inch drain valve on return cooling line was replaced in ITE. In the meantime two 1/2 inch valves labeled FEBIAD COIL and ENTRANCE COLLIMATOR RETURN at ITW were replaced . The 2 inches leaky supply/return water valves in ITW were repaired as well. Pls check pics

attached here for detail.

Two filters on HALCW resin circuit have been replaced. O-ring 235# were changed on both filter cartridge houses.  25micron  10"x 2.5" 3M cartridge new filters  are used. Old filters are not very dirty. They are bagged and stored in vacuum pit. Residual water from cartridge houses are collected and stored in high active storage jug with sealed cap.  No leak on resin circuit before and after the job.

I visually inspected HALCW system including water station section, both target pits, and de-ionizer system.  No small leak and drip was found .  The inspection in both target pits will be repeated after flow sensors are replaced.

HALCW flow sensors replacement job is done. All ITE/ITW(except ITE HS) return line water flow sensors including paddle wheels and coils are replaced.  After job, water interlock signal have been checked in electrical room .  Everything works fine. Visually inspections for possible water leak on HCLCW system have been done as well. one valve on ITE dump return line has a very small water seeping through valve stem. I will watch on it.  Other than that,  No major concern.

2023-03-08: leak on 1/2" ITE dump return line valve is fixed.

HALCW ITC:MP1/MP2 motor phase current measurement is done by Joel from electrician group. MP1:17.1A/17.2A/16.7A.  MP2: 17.9A/17.9A/17.3A.   19.5A is manufacturer notified on full load phase current.on operating  instruction manual. 

HALCW ITC:MP1/MP2 pump and motor temperature measurements result:

MP1: pump discharging  port: 78F,  motor rear bearing house:72F  , Motor housing 140F(60C). 6F difference between them is less than 15F manufacturer clarified up limit in instruction manual. 

MP2: pump discharging port:78F,  motor  rear bearing house:72F, Motor housing 122F(50C).

MP1 is better than MP2 on motor status. It could be seen on phase current measurements as well.

Other notes on pump performance:    total flow rate 60GPM , discharging gauge pressure  99 to 100 psi on both pumps with one station all of TM water circuits bypassed + other station  two of TM water circuits bypassed + both stations 2A beam related water circuits  on(2X5).

ITW, ITE, ITW +ITE total , and low active cooling water return flow meter transmitters are inspected and calibrated.  Result:

ITW , PX-750-06Di , Calibrated to  4-20 mA for 0 to 6" H2O DP, linear.    Transmitter works fine.

ITE. PX-750-06Di, calibrated to 4- 20mA for 0 to 6" H2O DP, linear.   Transmitter works fine.

ITE+ITW total, PX-750 -30 SQDI.  It looks like electronic board for square root output is broken. It can not be calibrated  to 4mA @ 0 inch H2O DP. The transmitter is calibrated to 10.25mA - 25.25mA for 0 to30" H2O DP, linear. Transmitter works fine.

 Low active cooling water return, Px-750-30di, smart.  The transmitter is broken. The output current stuck at 44.5mA on all DP.  I tried zero and reset it by following instruction manual, but failed to bring it back. The electronic boards are broken mostly. The production is discontinued by Omega Engineering. A new Omega transmitter PX3005-25WDWBI (linear) will be ordered for its replacement.

2023-06-28: A new Omega transmitter PX3005-25WDWBI (linear) has been installed back to LALCW system in target hall. Transmitter is calibration by manufacturer @ 4-20mA output@0 to 25 in H2O DP. Control group will finish the cable connection in TH, electrical room, and reprogram   on epic page on July -11th.

2023-07-12: Cable connection, formula reprogram, and epic page reboot are done yesterday by Ray.M. New transmitter works fine. All flow rates are displayed on epic page properly with new program formulas.

HALCW system O2 sensor service and calibration were done in Sep 26th. electrolyte and membrane on rose mount sensor 499ADO were refilled and replaced. Sensor was zero and full scale calibrated. The sensor works fine after the job.

100 liters of high active water from HALCW system( mostly from s-tank and pipe lines closing to pumps) are transferred to holding tank in 2A tunnel. Transfer is smooth.  it is a preparation job for ITC:MP1/MP2 refurbishment.  water sample is passed to RPG for assay.

both high active pumps ITC:MP1 and MP2 are refurbished by RH group Maico and Peter. Pumps have been installed back to system with new inlet/outlet flange gaskets. high active water surging tank is refilled with water and pumps were primed. I asked operator to switch on pumps separately. Both pumps work fine. They are quiet and pumps discharging pressure is a little bit better comparing to before refurbishment. Nitrogen gas is injecting into system. O2 level is decreasing and R is going up.

2024-04-09: Joel.S checked pumps phase current draw: MP1 16.8 to 17.1A on each phase. MP2 17.0 to 17.2 A on each phase. They are normal. Pump body temperature are below 45C which is fine.