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Rockwell Automation Publication 1606-RM111A-EN-P - July 2020
Lifetime Expectancy and
Mean Time Between Failure
The redundancy module has two input channels, which are completely
independent from each other. The dual-input redundancy module can be
considered as two single redundancy modules combined in one housing. The
only common point is the circuit trace that ties the two separate circuits
together at the output.
The Mean Time Between Failure (MTBF) values in the following table are for
the entire dual-input module. If you need the MTBF number of only one path,
double the value from the table.
Terminals and Wiring
The terminals are IP20 fingersafe constructed and suitable for field wiring and
factory wiring.
Wiring rules:
•
Use appropriate copper cables that are designed for minimum operating
temperatures of:
- 75 °C (167 °F) for ambient up to 55 °C (131 °F)
- 90 °C (194 °F) for ambient up to 70 °C (158 °F)
•
Follow national installation codes and installation regulations.
•
Ensure that all strands of a stranded wire enter the terminal connection.
•
Unused terminal compartments should be securely tightened.
•
Ferrules are allowed.
Input / Output Current Conditions
N+1 Redundancy
Input: 2 x 10 A
Output: 20 A
1+1 Redundancy
Input: 2 x 5 A
Output: 10 A
Notes
Lifetime expectancy
(1)
Min
113,000 h
309,000 h
at 24V and 40 °C (104 °F)
Min
320,000 h
874,000 h
at 24V and 25 °C (77 °F)
MTBF
(2)
SN 29500, IEC 61709
—
7,837,000 h
20,310,000 h
at 24V 40 °C (104 °F)
—
19,408,000 h
46,382,000 h
at 24V 25 °C (77 °F)
MTBF
MIL HDBK 217F
—
1,774,000 h
1,817,000 h
at 24V and 40 °C (104 °F) (Ground Fixed GF40)
—
2,709,000 h
2,782,000 h
at 24V and 25 °C (77 °F) (Ground Fixed GF25)
—
3,675,000 h
3,707,000 h
at 24V and 40 °C (104 °F) (Ground Benign GB40)
—
5,620,000 h
5,674,000 h
at 24V and 25 °C (77 °F) (Ground Benign GB25)
(1)
The Lifetime expectancy values that are shown in the table indicate the minimum operating hours (service life) and are determined by the
lifetime expectancy of the built-in electrolytic capacitors. Lifetime expectancy is specified in operational hours and is calculated according to
the manufacturer specification of the capacitor. The manufacturer of the electrolytic capacitors only states a maximum life of up to 15 years
(131,400 h). Any number that exceeds this value is a calculated theoretical lifetime, which can be used to compare devices.
(2) Mean Time Between Failure (MTBF) is calculated according to statistical device failures, and indicates reliability of a device. It is the statistical
representation of the likelihood of a unit to fail and does not necessarily represent the life of a product. The MTBF value is a statistical
representation of the likelihood of a device to fail. An MTBF value of, for example, 1,000,000 h means that statistically one unit fails every 100
hours if 10,000 units are installed in the field. However, it cannot be determined if the failed unit has been running for 50,000 h or only for 100 h.
Attributes
Values and Descriptions
Type
screw terminals
Solid wire
6 mm
2
max
Stranded wire
4 mm
2
max
American Wire Gauge
AWG20…10
Wire diameter max
2.8 mm (0.110 in.) (including ferrules)
Wire stripping length
7 mm (0.28 in.)
Screwdriver
3.5 mm (0.138 in.) slotted or cross-head No 2
Recommended tightening torque
1 N•m, 9 lb•in