SIEMENS
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Siemens IK PI · 2015
AS-Interface
Slaves
Modules with special functions
Overvoltage protection modules
4
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Overview
AS-Interface overvoltage protection module
The AS-Interface overvoltage protection module (protection
module) protects downstream AS-Interface devices or individual
sections in AS-i networks from conducted overvoltages which
can be caused by switching operations and remote lightning
strikes. The location of the protection module forms within the
lightning protection zone concept the transition from zone 1 to
2/3. Direct lightning strikes must be coped with using additional
protective measures at the transitions from lightning protection
zone 0A to 1.
With the AS-Interface overvoltage protection module, it is now
also possible to integrate AS-Interface in the overall overvoltage
protection concept of a plant or machine.
The module has the same design and degree of
protection (IP67) as the AS-Interface K45 compact modules. It is
a passive module without AS-i IC and as such does not need its
own address
on the AS-Interface network. The module can be
used to protect the AS-Interface cable and the cable for the aux-
iliary voltage from overvoltage. Overvoltages are discharged
through a ground cable with a green/yellow oil-proof outer
sheath. This cable is fixed in the module and must be connected
with low resistance to the system's ground.
Rated discharge current
I
sn
The rated discharge current is the peak value of a surge current
of the form 8/20
s (microseconds), for which the protection
module is designed in accordance with a specified test pro-
gram. With waveform 8/20, 100 % of the value is achieved after
8
s and 50 % after 20
s.
Protection level U
p
The protection level of a protection module is the highest
momentary value of the voltage at the terminals, established in
individual tests and characterizes the capability of a protection
module to limit overvoltages to a residual level.
Configuration guidelines
The grounding of protection modules and the units to be
protected must be effected through a shared grounding point.
If insulated devices are protected, their mounts must be
included in the grounding points.
Sample application
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Selection and ordering data
AS-
Inter-
face
AS-
Inter-
face
NSA0_00093a
OVP = Overvoltage protection
Mounting plate
Application
Device with
ground terminal
Device without ground terminal
→ Grounding of the mounting plate
Application
OVP
Version
Article No.
AS-Interface overvoltage protection module
3RK1901-1GA01
Delivery includes mounting plate
(for wall and standard rail mounting)
NSA0_00092b
AS-
Inter-
face
A
B
AS-
Inter-
face
AS-
Inter-
face
AS-
Inter-
face
OVP = Overvoltage protection
OVP
OVP
protected range
Zone 1
Zone 1
Zone 2
Protection approx. 5 m to the right
Equipotential bonding
(system earth)
Protection approx. 0.5 m to the left
© Siemens AG 2014