beautypg.com

6 safety manual – JUMO 701150 14597 safetyM STB/STW - Safety Temperature Limiter and Safety Temperature Monitor Operating Manual User Manual

Page 50

background image

6 Safety Manual

2014-05-01

50

M

Motor

Appendix I

MTTF

Mean Time To Failure

Appendix C

MTTF

c

Mean time to critical failure

3.1.25

MTTF

d

Mean time to dangerous failure

n, N, N

Number of units

6.3, D.1

N

low

Number of SRP/CS with PL

low

in an SRP/CS combination

6.3

O, O1, O2, OTE

Output device, e.g. drive unit

6.2

P, P1, P2

Possibility of avoiding the danger

A.2.3

PES

Programmable electronic system

3.1.22

PL

Performance Level

3.1.23

PLC

Programmable Logic Controller

Appendix I

PL

low

Lowest Performance Level of a SRP/CS in an SRP/CS combination

6.3

PL

f

Required Performance Level

3.1.24

r

a

Demand rate

3.1.30

RS

Rotary encoder

Appendix I

S, S1, S2

Severity of violation

A.2.1

SW1A, SW1B, SW1

Position switch

Appendix I

SIL

Safety Integrity Level

Table 4

SK (Cat.)

Category (B, 1, 2, 3, 4), structure as basis to achieve a certain PL

SRASW

Safety-Related Application Software

4.6.3

Formula symbol or
abbreviation

Description

Definition
or location