Discovery MR750 3.0T System Service Methods
5690009-2EN Revision 4
Object ID: 00000018WIA30430130GYZ
Topic ID: id_12373292 Version: 1.23
Date: Oct 11, 2021 3:47:52 PM

PDU/PGR Cabinet Replacement

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
1	Not Applicable	25 hours	1 hours

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
ESD Grounding Wrist Strap	1	-	-	-
Safety Glasses	1	-	-	-
Work Gloves	1 pair	-	-	-
MR Equipment Room Hoist Kit	1	-	5196226	-
Non-Magnetic Tool Kit	1	-	5113258	-
Water Removal Pump Kit (located in HEC)	1	-	5369683	-
5 gallon pail with handle	1	-	2239133	-
Cabinet Dollies	1	-	Order part 5338391 from UMI	-

Table 3. Consumables
Item	Quantity	Effectivity	Part number	Manufacturer
Cable ties	-	-	-	-
Towels or absorbent pads	-	-	-	-

Table 4. Replacement parts
Item	Quantity	Effectivity	Part number	Manufacturer
32-Channel PGR Cabinet	1	-	See FRU Manual	-
Lifting Bracket, XGA (or XGA2) and XPS FRU (comes with the PGR cabinet)	1	-	5263794	-
Hoist Bracket, HDv RF Amplifier (comes with the PGR cabinet)	1	-	5262278	-
Coolant, 4 gallons – non-copper corrosive, algae resistant	1	-	5174313-4	-

Table 5. Safety

Warning

Electric Shock Hazard!

High voltages are present in the PGR PDU/Gradient Cabinet.

LOTO the PGR breaker at the Main Disconnect Panel (MDP) before proceeding. See the “MR service Safety Manual,” PN 5452735.

CAUTION

Possible personal injury or equipment damage.

Components could fall while using the hoist.

Before putting weight on the hoist, be sure that the hoist chain links are aligned properly. This prevents the chain from binding up or becoming kinked, which is nearly impossible to correct when the chain is under tension.

Table 6. Required conditions
Condition	Reference	Effectivity
Power to the PDU from the Main Disconnect Panel (MDP) must be locked out and tagged out before starting this procedure. See the MR Service Safety Manual, PN 5452735. Power to the HEC remains on to permit cryogen compressor operation during this replacement.	-	-

About this task

Overview

This procedure describes removal and replacement of the components in the PGR cabinet in the instance where a PDU has failed, requiring a PGR cabinet containing only a PDU. Under normal replacement procedures, the only part that is replaced during this procedure is the PDU.

Topic ID: id_SL3446274-1103492

Disconnect Cabinet

Procedure

Turn off the power electronics pump on the HEC cabinet. Stop the pump by pressing ▲ F3 simultaneously. Turn the PPMP circuit breaker to the OFF position.
LOTO the PGR breaker at the MDP panel. See the MR Service Safety Manual, PN 5452735.
Turn the supply and return valves between the HEC and the PGR cabinet to the OFF position.

Figure 1. Turn OFF Supply and Return Valves
Drain enough coolant from the PGR cabinet so that when the fittings are disconnected at the top of the cabinet coolant does not flow into the cabinet. Perform this by placing the open end of the drain hose into a pail, and connect the other end to the quick disconnect on the return fitting (red hose) on a XPS or the RF amplifier. Connect the hand pump to the return fitting (red hose) on a XGA (or XGA2) assembly, and manually pump until approximately 1 gallon of coolant is removed (or enough to empty the hoses above the PGR cabinet).

Figure 2. Drain Coolant
Place towels around the top of the PGR to catch excess coolant. Using an adjustable wrench, disconnect the fitting connecting the coolant hose to the cabinet. After the cabinet is disconnected disconnect the drain hose. Follow local regulations for proper disposal of the coolant that was removed.
Disconnect the gradient load cables, data cables, and power cables from the top of the cabinet. Disconnect the fiber optic cables from inside the cabinet. Remove these cables from the cabinet so that the cabinet may be moved.

Topic ID: id_SL3446281-1103492

Remove Cabinet

Procedure

The PGR cabinet containing all the components must now be moved utilizing the moving dollies. The moving dollies can be ordered online at www.umi-dollyshop.com.
The dollies have the following features to aid in their use:
- Wheel locking pin - Keeps the wheels locked into a certain direction
- Parking brakes - Hold the cabinet in position
- Slide and lock - Allows dollies to be removed in limited space (15 inches or 381 mm)
- Twinning hardware - Connects each dolly to the other dolly during transport without a cabinet
Remove any seismic mounts from the PGR cabinet, if necessary.
Install the six bushings, three on each side, to the bottom of the cabinet (these came with the moving dollies).

Figure 3. Installation of Bushings
Maneuver the dolly so that all three bushings slip into the slide lock on the attachment plate.
Slide the dolly sideways to position the bushings in the lifting part of the attachment plate.

Figure 4. Position Dollies on Bushings
Raise the dolly by turning the jackscrew clockwise. This locks the dolly into position.
Secure to dollies with strap. Make sure the strap goes through the slot of the attachment plate, and the clamp is on the flat surface of the dolly.
Tighten the strap and close the clamp.
Lift the cabinet off of the floor by turning the jackscrew clockwise until the cabinet surface is 1 inch above the floor.

Alternate raising each dolly in 1/4 inch (6 mm) increments until the cabinet is above the floor. (The image below shows a pallet; however, the cabinet will no longer be on the pallet.)

Figure 5. Secure Dollies to Cabinet
Move the cabinet to a temporary location where there is enough space for each of the components to be removed. The cabinet should be in close proximity to the new PGR cabinet to allow for ease of component removal and replacement. Lower the cabinet to the floor and remove the dollies.

Topic ID: id_SL3446294-1103492

Position FRU Cabinet

Procedure

Move the FRU PDU/PGR cabinet into the place of the old cabinet. Unfasten screws for each angle shipping bracket and remove bracket from each side of cabinet. Follow Step 2 through Step 7 (above) to remove the cabinet from the pallet.
Lift the cabinet off the pallet by turning the jackscrew clockwise until the cabinet surface is free from the pallet surface.
Slide the pallet out from under the cabinet. Save this pallet to be used in returning the original PGR cabinet.
Lower the cabinet by turning the jackscrew counterclockwise until the cabinet is about 1 inch (25 mm) above the floor.

Alternate lowering each side of cabinet.
Move the FRU PDU/PGR cabinet into the equipment room and lower the cabinet into place.
Remove the dollies for attachment to the original PGR cabinet.

Topic ID: id_SL3446301-1103492

Replace Components

About this task

Do NOT perform the Finalization steps in the individual procedures. These will be completed when all component replacements are complete in the new PGR cabinet.

Procedure

Make sure the PDU in the new PGR cabinet is set up correctly (input voltage selection, AUX box versus PEM, etc.). See Teal PDU Installation and Maintenance for instructions on setting up the PDU.
Remove the three LEM DC current transducers located above the XGD amplifiers and reinstall them into the new PGR cabinet. A Phillips screwdriver and tie wraps are required for this replacement. Tie wraps are needed to connect the gradient output cable to the cable bracket.
Remove the X, Y, and Z XGD amplifiers and reinstall them into the new PGR cabinet by following the XGD Amplifier Replacement procedure.
Remove the three XGD fan box assemblies and reinstall them in the new PGR cabinet by following the XGD Fan Box Assembly Replacement procedure.

Notice

To avoid swapping axes, make sure the Octavius cables (the cables connecting J3 on the XGA (or XGA2) modules to J3 on the XPS modules) are connected to the correct units. The labels on the cables show the axis for which they are intended.

Remove the X, Y, and Z XPS units and reinstall them into the new PGR cabinet by following the XPS Replacement procedure.

Remove and reinstall the CAM chassis in the new PGR cabinet by following the CAM Chassis Removal/Replacement section of the CAM Chassis Replacements procedure.
(For systems with an auxiliary module) Remove the auxiliary module from the PGR cabinet by following the Auxiliary Board Replacement procedure. Do NOT reinstall the auxiliary module until the terminal server replacement (Step 9) is complete.
(For systems with a power equipment monitor (PEM)) Remove the PEM from the PGR cabinet by following the Power Equipment Monitor (PEM) Replacement procedure. Do NOT reinstall the PEM until the terminal server replacement (Step 9) is complete.
Remove and reinstall the terminal server in the new PGR cabinet by following the Terminal Server Replacement procedure.
(For systems with an auxiliary module) Reinstall the auxiliary module in the new PGR cabinet by following the Auxiliary Board Replacement procedure.
(For systems with a PEM) Reinstall the PEM in the new PGR cabinet by following the Power Equipment Monitor (PEM) Replacement procedure.
Remove and reinstall the Ethernet switch in the new PGR cabinet by following the Network Switch Replacement procedure.
Remove the RF amplifier.
- (For systems with 3.0T 35 kW RF coil) Reinstall it into the new PGR cabinet by following the XRFD and Power Supply Replacement procedure.
- (For systems with 3.0T dual drive RF coil) Reinstall it into the new PGR cabinet by following the Dual Drive RF Amplifier Replacement.
(For systems with a power distribution module (PDM)) The new FRU cabinet does not have a PDM. The new cabinet contains a terminal strip and an outlet strip for all the connections that were on the PDM.
(For systems with a Cronus chassis) Remove and reinstall the Cronus chassis in the new PGR cabinet by following the XGD Cronus Chassis section of the XGD Cronus Chassis Replacements procedure.
Remove and reinstall the ICN in the new PGR cabinet by following the ICN Replacements (4100 or 4170) procedure.

If the cabinet contains two 4100 ICNs, the slide rail must be removed from the old cabinet and placed in the new PGR cabinet to allow for mounting the second ICN. Follow the procedure for mounting the ICN rails as described in ICN Conversion Manual (4170 to 4100).
Connect gradient load cables X, Y, and Z. Connect the fiber optic cable set and data cable sets according to each cable’s label. Connect remaining power cables. If necessary, reference the block diagram for cable connections.
Reconnect the coolant hoses to the PGR cabinet, ensuring the supply (blue) hose and return (red) hose are installed on the correct fittings. Open the ball valves between the HEC and PGR cabinet.
Perform the PGR cabinet PDU setup on the new PDU. Instructions are found in Teal PDU Installation and Maintenance.
When the original PGR cabinet contains only a PDU, attach the shipping pallet to the cabinet and return both the cabinet and the dollies. Instructions for returning the dollies are included with the dollies.

Topic ID: id_15241571

Finalization

Procedure

Ensure all previously closed coolant valves are now open. Turn on the PPMP CB at the HEC. Start the pump by pressing ▲+F3 simultaneously. Air will push through the HEC reservoir as coolant fills the modules in the PGR cabinet. Add the required amount of coolant to the PE tank in the HEC to get the level about 3 to 5 inches from the top of the tank. Check the ball valves in the hoses, connections at the top of the PGR, and all quick-disconnects in the PGR cabinet for leaks.
Remove LOTO to restore the power to the MDP. See the MR Service Safety Manual, PN 5452735.
Check for leaks around the PGR cabinet fittings. Check the gradient reservoir and add coolant if necessary.
Bring up the system.
Run Quick Diagnostics (15 minutes) to verify operations.
Perform Grafidy 3 Eddy Current Calibration.
Perform LVShim.
Perform DQA II Tool and Troubleshooting.
Perform Body and Head Maximum Power Setup and Calibration.
Perform UPM Calibration and UPM Functional Check – Body Mode.
Perform UPM Calibration and UPM Functional Check – Head Mode.
(For dual drive) Perform Dual Drive Quadrature Tool.
To save the new information to the config files, perform a SAVEINFO.
Run a goodbye scan on the head, body and surface. See Check Scan.