2 - Schneider Electric CZ, s.r.o.
2 - Schneider Electric CZ, s.r.o.
2 - Schneider Electric CZ, s.r.o.
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Presentation<br />
Machine safety<br />
Hoisting applications examples<br />
Example of Safety chain<br />
with Emergency stop to reach Performance level c<br />
1<br />
2<br />
3<br />
Examples of safety chain with<br />
emergency stop<br />
Safety chain to reach Performance level PLc / SIL1<br />
> > Safety module type XPS AXE + Emergency Stop with 1 NC contacts<br />
A typical example of hoisting for manually controlled machine - the operator has to<br />
monitor the load of the crane and check there are no people near to the load. The<br />
operator must be trained and informed how to drive the machine. The operator<br />
monitoring is the first safety barrier.<br />
In case of any trouble the operator must stop the machine by pushing at the<br />
emergency stop. The emergency stop is the second safety barrier. What is now the<br />
safety level required for the emergency stop?<br />
Because of the operator is monitoring the area, it can be considered that the<br />
frequency and the exposure times are short.<br />
Performance level required in this case is PLr = c<br />
To reach to required PL (PLc), the following architecture of Category 1 type<br />
(1-channel) is proposed:<br />
4<br />
Required<br />
performance<br />
level PLr<br />
3 x 400 VAC<br />
24 VDC<br />
5<br />
6<br />
7<br />
8<br />
9<br />
Starting point for the<br />
evaluation of the<br />
contribution to the<br />
risk reduction of a<br />
safety function<br />
S = Severity of injury<br />
S1 = Slight (normally reversible injury)<br />
S2 = Serious (normally irreversible) injury including death<br />
F = Frequency and/or exposure time to the hazard<br />
F1 = Seldom to less often and/or the exposure time is short<br />
F2 = Frequent to continuous and/or the exposure time is long<br />
P = Possibility of avoiding the hazard or limiting the<br />
harm<br />
P1 = Possible under specific conditions<br />
P2 = Scarcely possible<br />
(1) Fault relay contact<br />
Motor<br />
Brake<br />
control<br />
Brake<br />
R2C (1)<br />
R2A (1)<br />
Related products:<br />
> > Emergency stop - Harmony XB4, See chapter 8<br />
> > Limit switch OsiSense XF, See chapter 9<br />
> > Preventa Safety Module XPS AXE, See page 7/28<br />
> > TeSys contactor (nominal load), See chapter 5<br />
> > Variable Speed Drive Altivar 312, See chapter 6<br />
The performance level reached (reference SISTEMA and <strong>Schneider</strong> <strong>Electric</strong><br />
SISTEMA library) with this combination of products is<br />
> > PLc and<br />
> > PFH(1/h) of 2,31e -6 which corresponds to SIL1.<br />
10<br />
7/22
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