Product Selection and Project Engineering
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917460330020
2019-05-13·HB00·III·en·03
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Electronic relay module
Series 9174
5
Product Selection and Project Engineering
Maximum inductance of an ohmic circuit (conductor inductance)
Design the inductance of the conductor when switching ohmic loads as follows based on
the switching current:
Typical values: 0.6 mH/km. Ask the cable manufacturer for the exact specification.
Maximum capacitance of a resistive circuit (conductor capacitance)
The maximum capacitance of the conductor is limited to 220 nF. This results in a typical
conductor length of 1 km.
DANGER! Explosion hazard during operation without a back-up fuse!
Non-compliance may result in serious or even fatal injury.
Only plan and operate the device if the required specification is met
(see the "Technical data" chapter).
When using the 8560/51-4242 Ex e fuse, do not exceed a short-circuit current
of 80 A.
Use one fuse for each device.
DANGER! Explosion hazard due to modules overheating!
Non-compliance may result in serious or even fatal injury.
Ensure compliance with the maximum switching frequency,
maximum capacitance, maximum inductance and characteristic of the connected
binary output (see following tables and chapter "Technical Data").
Maximum switching current [A]
Maximum inductance of the conductor
2
200 μH
1
800 μH
0.5
3 mH
Additional circuitry with a freewheeling diode is recommended. R. STAHL offers
compatiable accessories from Series 8453 (e.g. 145169 article number,
SB 550 encapsulated diode for installation in Zone 1 or 2).