WSR-88D Operational Support Facility April 14, 2000

MEMORANDUM FOR:	Operations and Maintenance Focal Points at All DOD and NWS WSR-88D Sites
FROM:	W/OSO41- Tim Crum Chief, Operations Branch
SUBJECT:	Update on TPMS Program and OSF Recommended TPS Operational Procedures
REFERENCE:	My Memos, 31 January 2000, Requested WSR-88D Transition Power Source Actions, and 24 February 2000, Update on TPS Program and OSF Recommended TPS Operational Procedures

This memo is an update on the WSR-88D Transition Maintenance Power System (TPMS) Program and an update on the OSF's recommended Transition Power System (TPS) procedures.

Several TPS units have experienced a catastrophic bearing failure or have been shut off because of audible/vibration indications that the bearings may be about to fail. Thirty of the 94 installed TPS units are turned off due to these problems, failure to pass installation acceptance tests, or awaiting engine generator modification. The government and the prime TPS contractor (Powerware) are discussing the TPS failures and the future of the TPMS Program. The resultant impacts for field sites are:

1. For sites that have their TPS units turned off, do not expect contractor repair until further notice.

2. Installation of new TPS units has been suspended until further notice.

No schedule will be provided for repair/retrofit/new installations until the contractor has provided validated fixes for the TPS unit. This validation will be accomplished through analysis and vigorous testing in the factory and field.

Reference my last memo; a change was made to the vibration detection firmware. This change is designed to detect bearings that are damaged. It will alarm at a certain vibration level and shut the unit down when the vibration levels reach a second threshold. This change was implemented on the OSF TPS and at five field sites, but results were not satisfactory. No further retrofits are expected until a more permanent fix is ready for implementation.

If your TPS unit is operating, we recommend you continue to make visual and audible checks of the unit when you are at the site. If your RDA is co-located with your office, we recommend a daily check. As in my January memo, visually and audibly observe the TPS for the following conditions:

1. Higher-than-normal vibration which may result in higher-than-normal noise,
2. High-pitched squealing noises from the TPS bearing area,
3. Strong burning smells, or
4. Magnet particles or pieces in the motor or generator control cabinets.

If you detect any of the above phenomena, we recommend that you transfer the TPS unit to maintenance bypass and shut down the unit. Then, please call the WSR-88D Hotline to report the problem as soon as practical. The Hotline will inform the government TPMS Contract Officer Technical Representative of the shut down.

If you have further questions/comments on the TPS operation, please contact the WSR-88D Hotline.