Operation And Maintenance; Overview Of Functional Tests; Diagnostics; Installation And Maintenance In High Altitudes - Danfoss iC7 Series Operating Manual

Operating Guide | iC7 Series Functional Safety

Operation and Maintenance

8

Overview of Functional Tests

8.1
Safety functions in the drive do not require scheduled functional tests or proof testing. Refer to application-specific standards and
requirements for scheduled functional and proof testing. Drive safety system mission time is 20 years. After 20 years, the whole unit must
be replaced.
COMPONENT FAILURE IN FUNCTIONS RELATED TO SAFETY
If a component failure occurs in functions related to safety, the drive must be replaced by authorized personnel.
It is not allowed to modify or repair the safety circuitry in any way.
l

Diagnostics

8.2
The iC7 drives include many diagnostic functions to ensure the integrity of safety functions. Diagnostics are, for example, temperature
monitoring, internal voltage monitoring, and safety function monitoring. The drive issues functional safety-related fault codes if any are
present. For safety-related fault codes, see
The Diagnostic Test Interval (DTI) depends on the safety function and the diagnostic function. The maximum DTI and Fault Reaction Time
(FRT) for each safety function are listed in
If functional safety-related diagnostics detects a failure, the relevant safety functions are always set to a safe state.
Multiple undetected hardware failures may lead to a mode where an external STO request does not lead to the de-energizing of the
motor. The PFH/PFD and MTTF values stated in
other STO-related, internal failures lead directly to an unrequested activation of the STO function, or affect only 1 of the 2 redundant STO
channels.

Installation and Maintenance in High Altitudes

8.3
If the drive is used in high altitudes, additional measures must be taken to ensure the integrity of the safety system. Since the safety
system includes controllers which are affected by cosmic radiation, it must be taken into account that the cosmic ray flux is higher in high
altitudes. The higher the flux of cosmic rays is, the higher is the risk of Soft Error Rate (SER) affected to the controllers.
To mitigate this issue, the safety system controller software must be updated at certain intervals depending on the altitude of the
installation. The software update rewrites the Read Only Memory (ROM) of the safety system and also forces the Random Access Memory
(RAM) to be reinitialized. This process resets any undetected failures in the memory which might be caused by cosmic rays.
Because SER affects the PFD and PFH values of the drive, the performance of the safety system is affected by high altitude. PFD and PFH
values are given for different altitudes and the given values assume that the safety system software is updated according to
Table 12: PFD and PFH Values, Altitude, and Safety Software Update Interval
Altitude
Sea level
1000 m (3300 ft)
2000 m (6600 ft)
Danfoss Drives Oy © 2024.09
WARNING
9.4 Event List.
10.1 Functional Safety Standards and
10.1 Functional Safety Standards and Performance
Safety software update
interval
No need for maintenance up-
dates for altitude reasons
5 years
4 years
Performance.
reflect the probability of this fault. Any
Average probability of
dangerous failures on
demand (PFDavg)
-4
1.8*10
-4
1.8*10
-4
1.8*10
AQ477043679710en-000102 / 172K2965A |
Operation and Maintenance
Table 12.
Average frequency of
dangerous failures per hour
(1/h) (PFH)
-9
3.5*10
-9
3.5*10
-9
3.8*10
33