Eaton Rapid Link RAMO5, Manual

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2 Engineering
2.8 STO function
56
Rapid Link 5 · RAMO5 · RASP5 10/19 MN034004EN www.eaton.com
The STO function is approved for use as a fail-safe method even in cases in
which the STO signal is not present and a single fault has occurred in the
drive.
The drive was accordingly tested in accordance with the following safety
standards:
The values specified here can only be observed if the STO function is
requested at least once every three months and if the RASP5 speed control-
ler is installed in an environment whose values meet the permissible limits:
• Ambient temperature range: -10 to +50 °C, taking into account any limits
that depend on frame size and protection.
• Maximum altitude for rated operation: 1000 m above sea level,
• Relative humidity: < 95 % (non-condensing).
The RASP5 variable frequency drive must always be free of frost and
moisture.

DANGER
In certain applications, additional measuring and monitoring
equipment may be needed in order to meet the requirements
for the system’s safety function.
The STO function does not include motor braking, and the
RASP5’s braking function cannot be considered a fail-safe
method by itself.
If a motor braking function is required, an appropriate safety
relay and/or a mechanical braking system or a similar method
must be used.
EN ISO 13849-1 PL e Cat. 3 MTTF
d
10000 years (High) DC
avg
91 % (Medium)
IEC61508 SIL 3 PFH
d
: 1.5 x 10
-10
1/h
(1.5 % of SIL 3)
(High demand or continuous
mode)
PFD
avg
(T1 = 20 years): 1.6 x 10
-5
(0.2 % of SIL 3)
(Low demand mode)
IEC62061 SIL CL 3
IEC61800-5-2 SIL 3
Cat. = Category
DC
avg
= Average Diagnostic Coverage
MTTF
d
= Mean Time to dangerous failure
PFH
d
= Probability of dangerous failure per hour
PFD
avg
= Average probability of dangerous failure on demand
PL = Performance level
SIL = Safety Integrity Level
SIL CL = Safety Integrity Level Claim Limit