ZIEHL STWA1 User manual

ZIEHL industrie –elektronik GmbH + Co KG
Daimlerstr.13, 74523 Schwäbisch Hall, Germany
+ 49 791 504-0, [e-mail], www.ziehl.de
Temperature Relays and MINIKA® Mains Monitoring Digital Panelmeters MINIPAN® Switching Relays and Controls Measuring Transducers Grid- and Plant Protection
Operating manual STWA1
updated: 2018-12-10 Fu
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- Current transformer for AC current detection - accessories for current relay STW
Table of contents
1Application and short description......................................................................................................... 1
2Overview of functions............................................................................................................................ 1
3Important Information ............................................................................................................................ 2
4Installation .............................................................................................................................................. 2
5Connecting diagram............................................................................................................................... 3
5.1 Tips................................................................................................................................................ 3
6Technical data ........................................................................................................................................ 3
7Housing................................................................................................................................................... 4
1 Application and short description
Current transformers STWA1 are inductive working single-ended current transformers. Due to the applied
measuring principle, these current transformers are only suitable for alternating current. The current
transformer STWA1 is used together with ZIEHL current relay type STW for current detection and control of
extraction systems. The level of the current to be monitored is limited to 100 A continuously, 300 A for max.
10s. The electrical connection is made via the lead out black cable.
2 Overview of functions
•Current transformer for alternating current detection
•connection to current-relays type STW
•no supply-voltage required
•plug-in current transformer (Ø 11 mm)
•length of the fixed connection cable 1000 mm

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3 Important Information
To use the equipment flawless and safe, transport and store properly, install and start professionally and
operate as directed.
Only let persons work with the equipment who are familiar with installation, start and use and who have
appropriate qualification corresponding to their function. They must observe the contents of the
instruction’s manual, the information which are written on the equipment and the relevant security
instructions for the setting up and the use of electrical units.
The equipment is built according to DIN / EN and checked and leave the plant according to security in
perfect condition. If, in any case the information in the instruction’s manual is not sufficient, please contact
our company or the responsible representative.
Instead of the industrial norms and regulations written in this instruction manual valid for Europe, you must
observe out of their geographical scope the valid and relevant regulations of the corresponding country.
DANGER!
Hazardous voltage!
Will cause death or serious injury. Turn off and lock out all power
supplying this device before working on this device.
DANGER!
In a non-loaded (open) secondary circuit of the current transformer STWA1 high
voltages are induced at the secondary terminals.
For primary currents > 16 A, this voltage can be dangerous for human beings.
An "open mode", i.e. operation of the current transformer without secondary wiring,
should be avoided.
4 Installation
The current transformer STWA1 is intended for installation in dry rooms. The STWA1 can be mounted as
follows:
•simply plug over the conductor to be monitored
•STWA1 e.g. secure with cable ties
DANGER!
The current transformer STWA1 is suitable for current detection in insulated cables.
At applications with non-insulated conductors the operator must take care for touch
safety. The insulation of the connection cables of the STWA1 must not be damaged.
When laying the cable, make sure that there is sufficient distance to not
isolated live parts (such as busbars).
If necessary, use an additional electric insulation hose.

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5 Connecting diagram
See operating manual of ZIEHL current relays type STW.
Attention!
There may only one conductor be lead through the transformer!
Attention!
The connecting cable can be extended up to 50 m. When laying parallel to
power cables use twisted or shielded cables.
Attention!
The polarity of the current transformer output (white marking on the cable) must be
observed only if several current transformers are connected in series to increase the
sensitivity.
5.1 Tips
Limit too high (current in wire too low):
•Loop through wire several times
Limit too low (small loads shall not be recognized)
•Connect a resistor (0,25 W / 200 V) in parallel to the current transformer STWA1(H)
➢- - resistor 750 Ohm = enhancement by factor 2x
➢- - resistor 330 Ohm = enhancement by factor 4x
➢- - resistor 150 Ohm = enhancement by factor 10x
Because of high tolerances we recommend to determine the best value by try out.
6 Technical data
Input / primary conductor
Rated thermal continuous current Icth
AC 100 A
Thermal rated short-time current Ith
AC 300 A for 10 s
Rated frequency
50/60 Hz
Max. Operating voltage Um
0.72 kV
Output
Max. output voltage U at Icth = 100 A
200 V peak (not limited)
Max. short circuit current I at Icth = 100 A
140 mA eff.
Test Conditions
EN 61010-1
Type test voltage
AC 2500 V 50 Hz 60 s
Installation conditions
Permissible ambient temperature
-25 °C ... +70 °C

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Permissible storage temperature
-25 °C …+70 °C
Installation height
< 2000 m over N.N.
Climatic conditions
5-85% rel. F., no condensation
Vibration resistance EN 60068-2-6
2 … 13.2 Hz ±1 mm 13.2 ... 100 Hz 1 g
2…25 Hz ±1.6 mm 25 ... 150 Hz 5 g
Housing
clip-on
Housing material
Polyamide PA66 blue
Flammability
UL94 V-2
Grouting
2 component-silicon RTV627
Protection class
IP 20
Outside diameter
31.3 mm
Height
18 mm
Connection cable
Wire LiYv 7x 0.25 (0.34 mm²) AWG 22 black
Wirelength
2 x 1000 mm
Stripping length
10 mm
Opening for primary conductor
11 mm
Mounting position
any
Weight
~ 43 g
Subject to technical changes
7 Housing