8
uptime
m
e
gazine · 01/09
renewable
energy
Severity
Type Description
RequiredAction
1
Danger Severe progressing failure
Immediate action. Operating the turbine has a serious risk of
functional loss and possible severe consequential damage.
2
Alert
Considerable progressing failure
Action as soon as possible. Recommended within 2 weeks.
3
Alert
Progressing failure
Action when convenient. Recommended within 2 months.
4
Alert
Small or no progressing failure
Action at next service.
5
Good
No abnormalities detected
No action required.
6
System Hardware system problem
Correct as soon as possible.
Cost efficient
implementation
ofcondition
monitoringon
alargeand
geographically
dispersed fleet
The examples from the previous
section clearly indicate the potential
benefits which condition monitor-
ing can bring to the operation and
maintenance of wind turbines. But
as outlined in the introduction a cost
efficient and successful condition
monitoring programme requires both
centralised monitoring and efficient
integration into the information- and
workflow of the service departments.
On a technical level systems must be
implemented which can cope with the
fact that both transient events (wind
gusts, yawing etc) and real faults can
initiate a cascade of warnings and
alarms. But the service department
Table 1. Severity classification of
alarms with estimated lead time to
service action.
Figure 5. The Alarm Manager
program evaluates incoming
and previous alarms.