- 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)
- UPS 1000Z (S/N: EDZ1-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. AVSpare 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 AVSpare. 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.
- 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.
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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. |
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- Inspect RPS ribbon and Top Thermistor cables. Move cables away from side of flywheel.
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| Illustration 1 | g03488837 |
Incorrect Routing | |
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| Illustration 2 | g03488838 |
Correct Routing | |
- Replace clamp on FWI-J2 ribbon cable with solid core toroid ( 250-3458 Ferrite Bead ) with 4 wraps.
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| Illustration 3 | g03488839 |
Before | |
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| Illustration 4 | g03488840 |
After | |
- Add two 420-5384 Clamps to ribbon cable between FWI and APC.
Note: This cable already has a solid core toroid with 4 wraps.
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| Illustration 5 | g03488856 |
RPS ribbon cable with camp - ferrite | |
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| Illustration 6 | g03488857 |
RPS ribbon cable with solid core toroid | |
- Reconnect UPSView to the effected MMU.
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| Illustration 7 | g03488876 |
- Enter service level password or higher.
- Perform Ctrl-j to view number of packet errors between FWI and the APC (FWI CRC Error Count) and reset the error counter.
- Wait 30 seconds and perform Ctrl-j a second time. Take note of how many packet errors are present.
- If many packet errors are noted, or unit continues to experience Load Cell - CM errors; have your Technical Communicator to contact AVSpare DSN for additional support.
- If the number of packet errors is reduced from those noted in Step 4, repeat steps 1 through 14 for all applicable MMUs.
Note: At least a 75 percent reduction in packet errors should be observed.
- Other things to look for:
- Ensure that APM heatsinks are not grounded.
- Ensure that FWI cables are not routed near high voltage components.
- Ensure FWI to APC ribbon cables are fully connected.