Beckhoff EL2904 - Target Failure Measures

Product description
EL2904 23Version: 3.2.2
Product designation EL2904
• Sulfur dioxide: (300 ± 20) ppb
Protection rating IP20
Device type according to EN 61010-2-201 Open equipment
Permitted operating environment In the control cabinet or terminal box, with minimum protection rating
IP54 according to IEC60529
Permissible installation position see chapter Installation position and minimum distances
Approvals CE, cULus, ATEX, TÜV SÜD
1
A corrosive environment exists when corrosion damage becomes apparent.
Derating table for altitudes above 2000m
The derating table (table 8) from the IEC61131-2:2017 standard can be referred to for the use of the
TwinSAFE components above the specified maximum altitude.
Altitude in m Derating factor for the temperature
1
0 to 2000
2
1.0
3000 0.9
4000 0.8
5000 0.7
Note: Linear interpolation is permissible between the altitudes
1)
Ambient temperature of the device at an altitude of 2000m
2)
The air pressure and air density increase as the altitude decreases. Therefore the derating factor for 0 to
2000 m (1.0) is used for altitudes below sea level.
Calculation example
In the following example the calculation is performed for a TwinSAFE component at an operating altitude of
4000m.
Permissible ambient temperature up to 2000 m above sea level = 55°C
Permissible ambient temperature up to 4000m above sea level = 55°C * 0.8 = 44°C
CAUTION
Compliance with the temperature limits
The TwinSAFE component has a maximum internal temperature at which a switch-off takes place. This is
designed for the maximum permissible ambient temperature. If the derating factor for the temperature for
higher altitudes is used, the user is solely responsible for ensuring that the calculated maximum ambient
temperature is complied with.
4.4 Target failure measures
Characteristic numbers EL2904
Lifetime [a] 20
Prooftest Interval [a] not required
1
PFH
D
1.25E-09
%SIL3 1.25%
PFD 8.45E-05
%SIL3 8.45%
MTTF
d
high
DC high
Performance level PL e
Category 4
HFT 1