GST GST-AS-200 User manual

30306435 Issue 1.02
Features
Aesthetical appearance and good protection
against interference.
Simple installation and operation.
Description
GST-AS-200, GST-AS-300 Zener Safety Barrier（the
barrier）is associated with intrinsically safe products. It
provides protection by limiting the energy into
explosive environment. Used together with
explosive-proof detectors and manual call points from
GST, the barrier is suitable for protecting the automatic
control process in modern industries such as
petroleum industry, chemical industry, pharmaceutical
industry, and ship yards.
The protection of the barrier is actually the limiting of
energy. In an explosion-proof system, the barriers
ensures the energy output always be controlled under
a safe value (that will not ignite the explosive gas
mixture classified and grouped according to relative
standards) in case of any kind of fault condition.
The barrier restricts the voltage through a voltage
stabilizing diode. When the input voltage rises sharply,
the diode will be turned on and control the output
voltage below the upper limit. The current of the diode
will rise sharply when turned on. If the input voltage is
too high or high voltage lasts too long, the fuse
connected in the circuit in series will be blown to cut off
the high voltage to the devices in field. When the load
in field is in short circuit, the current-limiting resistor in
the circuit of the barrier will limit the output current
below its upper limit.
Ex Area
Safety Area
Connection & Cabling
Terminals are shown below.
Description:
No.
Terminals
GST-AS-200
GST-AS-300
1
Non-intrinsically
safe side
Positive
Polarity-
insensitive
2
Non-intrinsically
safe side
Negative
(internal
earth)
3
Intrinsically
safe side
Positive
Polarity-
insensitive
4
Intrinsically
safe side
Negative
(internal
earth)
Installation
The barrier should be installed by copper busbar.
Warning: Power must be disconnected from the
loop before installation.
GST-AS-200/300 Zener Safety Barrier
Ssfety Area

30306435 Issue 1.02
Application
The figure below shows the application of the barrier.
Non-intrinsically safe loop
Hazardous AreaSafe Area
5 6 4
3
2
1
Primary instrument
Secondary instrument
Safety Barrier
Intrinsically safe loop
Specification
Operating voltage
24V
Max. voltage allowed
Um=250VAC/DC
Max. output voltage
U0=28V
Max. output current
I0=93mA
Max. external capacitance
C0=0.083uF
Max. external inductance
L0=4mH
Ambient Temperature
－20℃～＋40℃
Relative Humidity
≤95% , non condensing
Dimensions
96.9mm×20.9mm×58.4mm
Weight
About 0.12kg
The parameters of the barrier are shown below.
Model
Voltage
(V)
End resistor
(Ω)
Basic circuit
Non-
Intrinsically
safe
Intrinsically
safe
1-3
2-4
GST-AS-200
24
330
0
GST-AS-300
24
320
320
Cautions
1. The barrier should be installed in safe area.
2. Cables from intrinsically safe side and
non-intrinsically safe side should be connected
correctly. Note the lead polarity of GST-AS-200
barrier.
3. The barrier should be earthed. The resistance at
the earth electrode should not be higher than 1.
4. It’s prohibited to test the insulation between
terminals directly using a megohmmeter. Before
testing system connection, you must disconnect
the barrier.
5. Cables, and equivalent capacitance and
inductance distribution of connected devices at
non-intrinsically safe side should meet the safety
requirements of the barrier.
6. Installation, operation and maintenance of the
barrier should comply with this manual.
Limited Warranty
GST warrants that the product will be free of charge
for repairing or replacing from defects in design,
materials and workmanship during the warranty period.
This warranty doesn’t cover any product that is found
to have been improperly installed or used in any way
not in accordance with the instructions supplied with
the product. Anybody, including the agents,
distributors or employees, is not in the position to
amend the contents of this warranty. Please contact
your local distributor for products not covered by this
warranty.
1
2
3
4
5 6
1
2
3
4
5 6
This Data Sheet is subject to change without notice. Please contact GST for more information or questions.
Gulf Security Technology Co., Ltd.
No. 80, Changjiang East Road, QETDZ, Qinhuangdao, Hebei, P. R. China 066004
Tel: [phone] Fax: [phone]
[e-mail] www.gst.com.cn