PISTON 2N6730 - Caterpillar

Uninterruptible Power Supply: UPSB505 (S/N: YTM1-UP)Introduction
This Special Instruction contains information of new IGBT driver assembly that has been released to production to decrease the IGBT failure rate and limit the effects of an IGBT failure.Do not perform any procedure in this Special Instruction until you have read this Special Instruction and you understand this information. Use only proper tools and observe all precautions that pertain to the use of those tools. Failure to follow these procedures can result in personal injury.ReferenceTesting and Adjusting, UENR1799-00, "UPSB505 Uninterruptible Power Supply UPS Battery - 50Hz"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 should 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 that might involve a potential hazard.Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, the user must ensure that it is safe for the user and for other people to use.The user should ensure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.
Power source must be disconnected before working on equipment.Failure to disconnect power source could result in injury or death.
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.
Personal injury or death can result from high voltage.Moisture can create paths of electrical conductivity.Make sure that the electrical system is OFF. Lock out the starting controls and tag the controls "DO NOT OPERATE".
New IGBT Driver (DRV6T)
Redesign of the IGBT Sub-Assembly
Illustration 1 g03544976
Old Design of IGBT
Illustration 2 g03544980
New Design of IGBTUPSB505 New Driver Architecture
The new driver architecture of UPSB505 are shown in the Illustration 3 and 4.
Illustration 3 g03551176
(1) New IGBT driver boards DRVxT + new snubber caps (2) New Ribbon Cable (3) New Ferrite for dry contact EMC protection
Illustration 4 g03551318
(4) New Firmware AQ mini (5) New INOUT Board (6) New Cable between INOUT and EXPUT Board (7) EXPUT rev JA miniNew EMC plate for 500KVA Integrated parallel only.
Illustration 5 g03551337
(8) EMC plate installedIGBT Driver Comparison
The comparison between the current driver design and the new driver design is given in the following Table 1.
Table 1
500 KVA Current Design    500 KVA New Driver Design