From wagner@fnal.gov Thu Nov 15 07:57:30 2001 Date: Wed, 14 Nov 2001 19:14:31 -0600 From: Bob Wagner To: mukherjee@fnal.gov, Morris Binkley , JC Yun , ambrose@fnal.gov, burkett@cdfsga.fnal.gov, Nigel Lockyer , Robert Roser , Ken Schultz Subject: Second pass at COT wire pull procedure [ Part 1, Text/PLAIN (charset: ISO-8859-1 "Latin 1 (Western Europe)") ] [ 228 lines. ] [ Unable to print this part. ] [ The following text is in the "iso-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Procedure to Extract the broken sense wire. Background: ------------------- -The broken wire is SL5-161-S11. It is broken about at the pultrusion and much is certainly "coiled up" at the WEST endplate, where P11 and P12 are shorted to ground (3.2ohm and 4.2ohm on WEST, respective). The wire extends down and touches SL6-185-P0 somewhere on WEST side of the chamber (77 ohms from EAST and 14 ohms from WEST). -We wish to extract the wire from the chamber, cut it cleanly at the West endboard and pot the stub with corona dope. Since the stringing engine is not yet operational, we will use pullies attached to the survey IBEAM (the cell just happens to be at a convenient location for this). Preparation: ------------------- -Tue, 11/13: Mount WEST I-beam and measure distance to beamline and endplate. --Distance from surface of I-beam to beamline center: 10 3/8" --Distance from B0 side of I-beam to Quad side of Extrusion: 38" -->Calculate nominal pully height on EAST (low side) and WEST (done on 11/14 by Aseet) -Wed, 11/14: Practice removing a scrap wire plane from the prototype. -->11/14 17:43: One practice run was successfully done on the stringing prototype. At least one more practice run will be done on 11/15 before the procedure (JHA) is finalized. -Wed, 11/14: Measure the "Before" leak rate. Run a P5 line for "after" leak checks. (Del and company). -->??? Was this done ??? -- I will check in the morning of 11/15. -Wed, 11/14: Drain the SUVA. (Rob and company) Note that our electronics will be off until the repair is finished. -->11/14 08:50: 3v off to ASDQs at switches, caution tag about SUVA. -->11/15 Check with Dean or Bruce early morning for removal of line on WEST. -Wed, 11/14: Pull power cord on USE LV filter box (kills 5v) -->11/14: DONE. -Lock out high voltage (keys in cabinet). -->11/14 08:50: Crowbar box keys removed and locked in cabinet. Procedure: ----------------- -Verify: High voltage locked out and power cord pulled from USE LV filter box. ---> 11/14 DONE. -Remove HVDBs and ASDQ DBs from area. Use judgement as to how many are necessary. HV daisy chain must also be moved out of the way. It's not clear whether or not ASDQ angle brackets can stay (likely not): If time, do this on Wed 11/14. --Suggest start by removing ASDQ DBs 5-158/159, 160/161 and 162/163; HVDBs 5-159, 160, 161, 162. --> 11/14 DONE. **During any part of the procedure, we must not allow conductors to fall into the chamber region. Back-up work with tape, etc., when necessary.** -Crack open the HV motherboard on the WEST and ASDQ motherboard on the EAST -- With hot knife, score a "break" in the bead along the extrusion. This will prevent the crack from spreading in phi. --Use chisels and such, as per Ken's instructions, to remove epoxy around MB. -Mount the pulleys at the nominal calculated position on the IBEAM (see above). The pulleys and jacks are mounted to unistrut uprights via angles, so that their coarse position can be easily changed. The fine positioning will later be done with the jacks. -Double check that the pully washers are oriented properly (ie, the pulley really does lock). To lock the pulley, always tighten the wing nut WITHOUT the washer. -Speaker phones should now be hooked-up to allow good communication between the EAST and WEST endplates. Have walkie-talkies there as a back-up. -Attempt to shine the laser pointer through the slot ends to better align the pullies. (If this is difficult, a further procedure will deal with the problem below). I. WEST 1. Attach a safety string to board. 2.CA a G10 piece to the endplate, separated to the endboard edge by the thickness of a parallel. (Later carefully clean off the CA). This will later allow the correct "re-seating" of the wire plane even if the "nib" is bad. Tape it to prevent accidental knock-off. 3.Crack off G10 piece on wedge side of endboard. 4."Angle out" wedge while "angling in" temporary wedge to a perpendicular position at cell center. II.EAST Repeat I.1 to I.4 for EAST. III.BOTH EAST and WEST 1.Large portions of the EAST and WEST slots are now clear, so one can see through to the other side. Shine the laser through the opposite slot and better align the pullies on both WEST and EAST. 2.Crack off epoxy between ledge and endplate. 3.Remove safety strings one at a time and attach stringing hooks to pulley. Attach 2.5 lb weights to each pulley. Shine the laser from opposite end and again adjust the pulley position. Lock all pullies. IV.WEST 1.Unlock the WEST pulleys. 2.Remove the wedge and pull the ledge free by hand (usual way). Adjust pulleys so that the endboard is free and centered in the slot. Lock the pulleys. V.EAST: Repeat IV for EAST. One may have to make another centering iteration on each side. -Look inside for the wire. -Unlock the EAST pulleys. -Have Mylar funnel available on the WEST side to help prevent wires from rubbing the edge of the slot if needed. -Put fingers on WEST pulleys (for a break) and unlock the WEST side. Rotate pulleys with thumb and index finger and start moving the plane from the slot. GO SLOWLY. Soon after moving, lock the WEST pullies and re-center the endboard in the slot. People on the EAST will make sure that the EAST endboard passes freely through the slot. -After the endboard clears the slot by a few inches, lock the WEST pulleys. -Pull the broken wire out of the chamber. Have an ohmeter handy to track progress (eg, does the short in 6-185-P0 disappear). Save the wire and measure the length to confirm that all is out. -Snip the wire epoxy and pot the stub with corona dope. -Lock the EAST pulleys and unlock the WEST pulleys. -Use a Mylar "funnel" to help guide the EAST endboard into the slot. -Using the thumb and index finger technique, release the EAST pulleys and move endboards back into the slot. People on the WEST can keep their endboard well centered by hand. Some back and forth may be necessary. (If one could not tell whether the remaining 1/2 wire has reasonable tension, pull the East endboard through the slot and examine the wire.) -Latch the WEST ledge and install the wedge. Move the endboard against the G10 piece + parallel. -Pull and latch the EAST ledge by hand. Install the wedge and move the endboard against the G10 piece + parallel. -Check for shorts with an ohmeter, before gluing the endboards back to the endplate. -Remove the G10 seating pieces and clean off the CA. -On the benchtop, modify the ASDQ motherboard for cell 161 to tie S11 to P11. -Attach the HV motherboards and check for continuity with an ohmeter. -Attach the ASDQ motherboards and check for continuity with the capmeter. Remember to put the dummy daughterboard in the ASDQ MB. -Epoxy the motherboards using DP-110 and the mylar strips (between boards). -Let set for 1/2 hour, and start flowing P5 at 60SCFH. -After about 1 hour, check for leaks and patch as necessary. -Repeat the "after" total leak rate measurement with nitrogen, then flow nitrogen at 60 SCFH. -Install the SUVA and get running again. -Install electronics, doing the usual capmeter checks as we go. -Check SL5 and SL6 at 5% HV (hopefully there will be no "battery effects"). -Use Spy or the readout to check readout connections. -Button up, install the baggie, wait until oxygen level is less than 1000 ppm before running up high voltage in nitrogen. Equipment Reminder -------------------------------- -G10 pieces and parallel to "re-seat" endboards. -Hot knife, chisels for removing motherboards. -Cork/tube attachment for vacuum. -Little weights (add to 2.5lb for pulling planes). -Corona Dope -DP110 (two new tubes). -Nitril gloves -harinets -mylar strips for gluing MBs -Wedges -angles (Aseet) -Plane puller (Kourosh, if time) -mylar funnels (both 5 and 10 mil available) -Kapton (small sheets for protected wires in slots) -CA (superglue) -Red leak detectors (syringe tips and vacuum?) -String and wires for pulling wire planes -Magnifying glass and flashlights. -capmeter and ohmeter -Q-tips and Kay-drys. -Speaker phones and walk-ie talkies