---------------------- Forwarded by Mark V Walker/EWC/Enron on 04/22/2002 
05:16 PM ---------------------------


Garth Ripton
04/22/2002 07:09 AM
To: Paul Landers/EWC/Enron@Enron
cc: Mark V Walker/EWC/Enron@ENRON, Kevin Cousineau/EWC/Enron@ENRON 

Subject: Repair/Maintenance counter behavior

Hi Paul,

Sorry I didn,t get back to you after you called on Friday. I went over the 
Bachmann code over the weekend (and, today, confirmed the timer behavior with 
Gert). If the turbine is in "maintenance" for any reason such as the physical 
maintenance switch is on or any manual mode is active due to:

1. Hydraulic service switch on (status 47)
2. Rotor lock engaged (status 108)
3. Generator fan service switch on (status 148)
4. Axle box maintenance switch on- battery power disconnected from pitch 
motors (status 164)
5. Hub control box switch is in manual position (status 165)
6. Release brake button in the top-box is activated (status 171)
7. Manual pitch setting is active (status 185)
8. Manual generator speed setting is commanded (status 186)
9. Manual torque setting is commanded (status 187)
10. Manual disconnection from the power grid (status 188)
11. Manual yaw operation is commanded (status 189)
12. Manual generator fan operation is commanded (status 191)

then the maintenance timer will increment. If the manual repair switch is set 
while the maintenance mode is active then the repair timer will increment 
(and the maintenance timer will stop incrementing). This should answer Mark 
Walkers concern that the maintenance/repair switch will always take 
precedence over any manual mode command.

Also note that there should be a correction to the list that Erik was 
publishing for which timers are incremented during various fault conditions. 
Fault 165 increments "maintenance time" not "system OK" time.