Nord Drivesystems SK 510P - 3 Options

Functional Safety – Supplementary manual for series SK 500P
54 BU 0630 en-2020
Example
In the section “Example of multiple device operation”, a minimum input voltage of 
_24,
21.1  was
determined for the example of application class B. If in this example, the width of the test pulse is
t
OSSD
= 0.85 ms the minimum input voltage is increased by a further 1.0 V to 
_24,
22.1 . If in this
example a 24 V voltage source with a tolerance of 10 % is used (V
Q,min
= 21.6 V), this would be too
small, i.e. a source with a smaller tolerance, a shorter test pulse width to the OSSD, or a larger cable
cross-section are required.
Pos: 32 4 /Allg emein/ Allg emeing ültig e Mod ule/---------Sei tenumbr uc h k omp akt --------- @ 13\mod_1476369695906_0.docx @ 2265495 @ @ 1
Pos: 325 /A nleit ung en/El ek tr onik /Saf ety /8. Z us atzi nfor m ation en/ 7. Sich erh eits ein st ufung en/ !Sic her hei ts einst ufu nge n @ 1 5\mod_1485524952598_388.docx @ 2317090 @ 2 @ 1
7.2 Safety categories
Pos: 32 7 /Anlei tung en/El ektr onik/S afety /8. Zus atzin form ationen /7. Si cherh eitsei nst ufunge n/IEC 60204-1: 201 6 @ 44\mod_1594804675848_388.docx @ 2646337 @ 3 @ 1
7.2.1 IEC 60204-1:2016
(German version EN 60204-1:2018)
The requirements of category 0 and category 1 stop functions can be fulfilled by the Safe Pulse Block.
Controlled stopping of a category 1 stop function is not fail-safe via the standard functions of the
frequency inverter. The switch-over to the category 0 stop function is fail-safe.
Pos: 32 9 /Anlei tung en/El ektr onik/S afety /8. Zus atzin form ationen /7. Si cherh eitsei nst ufunge n/618 00-5-2:2016 @ 44\mod_1594804770366_388.docx @ 2646375 @ 3 @ 1
7.2.2 IEC 61800-5-2:2016
(German version EN 61800-5-2:2017)
The requirements for the Safe Torque Off (STO) function and the safety integrity level SIL 3 can be
fulfilled with the safe shut-down method Safe Pulse Block.
The requirements for the “Safe Stop 1 time-controlled” (SS1-t) function and the safety integrity level
SIL 2 can be met with the combination of Safe Pulse Block and Safety Digital Input.
With the SS1-t function, there is no safe monitoring of motor speed reduction or motor speed by the
frequency inverter. If a risk analysis shows that monitoring is necessary, this must be performed by an
external safety control unit. The solution for the SS1-t function described in the examples corresponds
to characteristics as per IEC 61800-5-2:2016, Section 4.2.3.3, Paragraph c) “Triggering of motor
speed reduction and triggering of the STO function after an application-specific time delay". The motor
speed reduction is carried out via the standard functionality of the frequency inverter and is not fail-
safe. Switchover to the STO function is carried out as fail-safe via an external safety control unit, e.g. a
protective switching device.
I.e. triggering of the motor speed reduction via the Safety Digital Input can meet the safety integrity
level SIL 2. The externally performed transition to the STO function can meet the safety integrity level
SIL3.
NOTE: Controlled stopping by the SS1-t function can fail without detection. Because of this, the SS1-t
function cannot be used if such failure could cause a hazardous situation in the end application.
The fault response function of the Safety Digital Input is the STO function. If a fault is detected in the
Safety Digital Input during motor speed reduction, the motor outputs are switched off by the software.
This behaviour corresponds to the STO function.
Pos: 333 /A nleit ung en/El ek tr onik /Saf ety /8. Z us atzi nfor m ation en/ 7. Sich erh eits ein st ufung en/ IEC 615 08: 201 0_01 [S K 5 00P] @ 4 4\mod_1594804552539_388.docx @ 2646299 @ 3 @ 1
7.2.3 IEC 61508:2010
(German version EN 61508:2010)
The shut-down method Safe Pulse Block for implementing the STO safety function meets the
requirements for safety level SIL 3. The Safety Digital Input for triggering motor braking for the function
SS1-t meets the requirements for safety level SIL 2 (see 7.2.2 "IEC 61800-5-2:2016")
Pos: 33 6 /Allg emein/ Allg emeing ültig e Mod ule/---------Sei tenum bruc h k omp akt --------- @ 13\mod_1476369695906_0.docx @ 2265495 @ @ 1