GASKET 4H9008 - Caterpillar

Uninterruptible Power Supply: UPS 1000S (S/N: CZS1-UP) UPS 1000Z (S/N: EDZ1-UP) UPS 120 (S/N: CNK1-UP) UPS 1200S (S/N: CZT1-UP) UPS 1200Z (S/N: HDR1-UP) UPS 150 (S/N: CPC1-UP) UPS 250 (S/N: BEE1-UP; CNM1-UP; APZ1-UP) UPS 300 (S/N: CNJ1-178,180-271,273-308,312-352,376-418,420-425,427-476,477-UP; CPZ1-312,315-319,321-321,323-323,325-325,331-331,351-364,366-378,379-UP) UPS 301 (S/N: CSY1-UP) UPS 500 (S/N: CSE1-UP) UPS 600 (S/N: CTX1-UP) UPS 750 (S/N: CPM1-UP) UPS 900 (S/N: CRY1-UP) UPS500G (S/N: TYD1-UP) UPS600G (S/N: DLD1-UP)Introduction
This Special Instruction describes the Inspection procedure for the MMUs experiencing Load Cell - CM errors that are accompanied with high packet errors and corrective actions for affected units.Note: the MMU must be online and running at nominal speed prior to viewing number of packet errors (Ctrl-j).ReferenceRefer to Systems operation, Testing and Adjusting, RENR9988, "UPS 120, UPS 150, UPS 250, UPS 300, UPS 301, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supplies".Important Safety Information
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.A person must be alert to potential hazards. This person must also have the necessary training, skills, and tools in order to perform these functions properly.Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance of a potential hazard.Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. Avoid using a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar. If used, ensure the safety of the operating personnel and others.Procedure
Inspect any MMU experiencing nuisance Load Cell - CM errors accompanied with high packet errors. Perform corrective actions as noted in the following procedure.
Connect to the suspect MMU with UPSView.
Enter service level password or higher.
Perform Ctrl-j to view number of packet errors between FWI and the APC (FWI CRC Error Count). This also resets the error counter.
Wait 30 seconds then perform Ctrl-j a second time. Take note of how many packet errors are present.
Disconnect UPSView.
High voltage may be present. The power source must be disconnected before working on the equipment. Failure to disconnect the power source could result in injury or death. Verify that the equipment is not energized before performing any maintenance. This work must be performed by trained personnel with correct tools and procedures.
Inspect FWI to APC ribbon cables. Move cables a few inches toward the front of the cabinet. Ensure that cables do not touch the AC filter capacitors.
Illustration 1 g03488837
Incorrect Routing
Illustration 2 g03488838
Correct Routing
Inspect RPS ribbon and Top Thermistor cables. Move cables away from side of flywheel.
Illustration 3 g03488839
Before
Illustration 4 g03488840
After
Replace clamp on FWI-J2 ribbon cable with solid core toroid ( 250-3458 Ferrite Bead ) with 4 wraps.
Illustration 5 g03488856
RPS ribbon cable with camp - ferrite
Illustration 6 g03488857
RPS ribbon cable with solid core toroid
Add two 420-5384 Clamps to ribbon cable between