[Dsg-hallb_magnets] Solenoid tests and modifications

[Pablo Campero]

Hello, 




To summarize the test and modifications performed on the Solenoid we can mention: 




1. On 09/05/2018 it was performed a test to verify the timing between the PLC SOE and FastDAQ data/ FastDump switch opening. 

Solenoid ramped up to 100 A (two times) and fast dumped intentionally later to monitor the sequence of the events and the timestamps for the FastDAQ data. During this test QD#1 tripped first after the Fast_Dump button was pushed. 

As the outstanding of this test, it was found the following timing differences based in the SOE timestamps and FastDAQ data timestamps: 

Test #1: 

FastDAQ_QD1 - SOE _Fast Dump Relay was ~ 270.8 ms. 

FastDAQ_IDCCT1 - FastDAQ_QD1 was ~36.6 ms 

SOE_QD1 - FastDAQ_QD1 was ~ 34 ms. 

Test #2 : 

FastDAQ_QD1 - SOE _Fast Dump Relay was ~ 284.2 ms. 

FastDAQ_IDCCT1 - FastDAQ_QD1 was ~26.3 ms 

SOE_QD1 - FastDAQ_QD1 was ~ 34.7 ms. 



For more details about this tests please refer: https://logbooks.jlab.org/entry/3593687 




2. Today 09/07/2018 it was performed the swapping of QD#1 and QD#2 units by two QD spares modified. 


Two spare Quench Detector units were modified by DC group with the aim to find more stability during the magnet operations. Modifications were applied to their hardware components as follow: 

- Changed eight potentiometers for each channel (2 potentiometers per channel, one is used for gain and the other for balance). Pots changed from 12 turns to 25 turns. 

- Modified LED voltage source wiring. LEDs used as indicators for QD-Ch lower/upper and Sum. 

The following steps were followed for the swapping of the QDs: 

2.1. Ramped down the Solenoid to 0 A. 

2.2. Connected a external power source to enable control power in the MPS. 

2.3. Took off and disconnected QD#1 and QD#2 units from the controls rack. 

2.4. Installed modified QDs, re-connected power cable, and signal/control cables. 

2.5. Found issues with the modified QD replaced as QD#2. (fixed later by Onish/DC group- changed Octo/component on QD#2 board) 


2.6. Tuned QD#1 and QD#2. Set up gain/ balance pots and set voltage thresholds as previous ones (0.1 and 1.5 V) 

2.7. Recorded values at which QD channels tripped. 

2.8. Set up delay time thresholds (200 and 999 ms)for each channel and make sure that all were recorded in the QDs memory. 

2.9 Tested QDs by tripping them when thresholds were exceeded. 

2.10. Removed control power for MPS and put it back to normal. 




After tunning was completed and returned all controls/instrumentation(VT panel) to normal operations the solenoid was ramped up to 250 A, it will be kept at this current over this weekend. 

The next step will be ramp the Solenoid up to full current (2416 A) on Monday and test the modifications made in QDs. 




Best Regard, 

Pablo 













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