Correct installation
For the installation of electrical systems in areas with explosive gas atmospheres of group II, rule IEC 60 079-14 (EN 60079-14) will apply.

Electric circuits of protection types d, e, q, o, m, p
Installation in the panel is identical to ”standard” installation, however the pro-
cedures for connecting Ex equipment must be followed. This refers, for example to voltage, current, fuses and motor protection equipment, etc. The require-
ments for specific products must be taken from their corresponding test certifi-
cates, standards and prescriptions as well as from the guidebook. It is only permitted to work on electric circuits within the Ex-area (for example when connecting to Ex-e terminal box if the voltage has been switched off). An Ex-e terminal box should only be opened after the voltage has been switched off.

Electric circuits of protection type „i“ (intrinsically safe)
For the planning and operation of switchgears and control systems installed in the safe area, but which contain circuits leading into the Ex-area, certain requirements should be considered. This applies especially to intrinsically safe circuits. Intrinsically safe circuits and non-intrinsically safe circuits should be kept separate. Minimum distances (distances) between bare connections must be observed, the cables must not produce any inadmissible external induc-
tance or capacitance. The maximum admissible electrical limits of Ex-i equip-
ment must be observed at all times. Intrinsically safe and non-intrinsically
safe electrical circuits should not cross, however it is allowed between two in-
trinsically safe circuits. Intrinsically safe circuits must be clearly marked.

Intrinsically safe circuits are marked by a „light blue“ color. This color is re-
commended for all intrinsically safe circuits to prevent confusion and/or linking up to a non-intrinsically safe circuit. Examples: cabels, cables, cable conduits, dampers, connection boxes, cable connectors,...

A minimum distance of 50 mm should be allowed between intrinsically safe and non-intrinsically safe circuits, and a minimum distance of 6 mm between two different intrinsically safe circuits. During installation the cables of intrinsically safe and non-intrinsically safe circuits should be laid out separately!

Suggestion on how to create a pannel
It is necessary to keep intrinsically safe and non-intrinsically safe equipment separate. It is recommended, in this case, that a sufficient distance be kept, to avoid extra costs in the future.

Large transformers, frequency rectifiers, large relays and other electric equip-
ment that may influence intrinsically safe circuits by inductance or capacitance should be installed at a sufficient distance. As a precaution Ex-i equipment should have a suitable cover to protect it from incorrect handling. The appro-
priate standards and regulations must be observed.

Schischek actuators are approved for direct installation and operation in explosion risk areas, as they are of the highest explosion groups and temperature class and are suitable for all gases, vapors, steam and dust. The electrical connection is made via an explosion proof terminal box (type ExBox-...). Please ensure during installation that all cables are securely fixed and connected in such a way that they are protected from mechanical damage.

In this example the control system consists of an actuator and a ExCos-D transducer with ExPro probe. The combination can be installed directly into the Ex area. The transducer converts the probe signal into an active signal (0...10 VDC or 4...20 mA) for input in a PLC systems. The output signal from the controller goes directly to the actuator. Between sensor and control-
ler is no additionally Ex i module and also no intrinsically safe (IS) wiring methode required. For the actuator and transducer the maximum permissible surface tempe-
ratures have to be taken into account.

In applications for fire/smoke dampers, the actuator has to reliably return the damper to its safety position via an external switch/contact. The actuator will return the damper to its safety position by an internal spring. The contact comes from a safety thermal trigger type FireSafe which is direct connenced to the actuator.

In this example the control system consists of an actuator and a ExCos-D transducer with ExPro probe. The combination can be installed directly into the Ex area. The transducer converts the probe signal into an active signal (0...10 VDC or 4...20 mA) for input in a PLC systems. The output signal from the controller goes directly to the actuator. Between sensor and control-
ler is no additionally Ex i module and also no intrinsically safe (IS) wiring methode required. For the actuator and transducer the maximum permissible surface tempe-
ratures have to be taken into account.

In this example the control system consists of a valve actuator and an ExCos-D trans-
ducer with ExPro probe. The combination can be installed directly into the Ex area. The transducer converts the probe signal into an active signal (0...10 VDC or 4...20 mA) for input in a PLC systems. The output signal from the controller goes directly to the actuator. Between sensor and control-
ler is no additionally Ex i module and also no intrinsically safe (IS) wiring methode required. For the actuator and transducer the maximum permissible surface tempe-
ratures have to be taken into account.

In this example the control system consists of an actuator and a differential pressure ExCos-P transducer. The combination can be installed directly into the Ex area. The transducer converts the differential pres-
sure signal into an active signal (0...10 VDC or 4...20 mA) for input in a PLC sys-
tems. The output signal from the controller goes directly to the actuator. Between sensor and controller is no additionally Ex i module and also no intrinsically safe (IS) wiring methode required. The controller, situated in the safe area will, depending on changing circumstances being monitored, control a fan (must be Ex proof) or a mo-
dulating damper actuator (also Ex proof) to maintain the required air volume/pressure.

Thermostats are passive switching equipment without any electrical energy supply of their own (type TB...). The switching function is performed mechanically. The integrated switches are within a circuit designed as intrinsically safe by using a switching module (type EXL-IRU-1). The switching module should be installed in the safe area. The output contact can be used for sequence functions (relays, contacts, direct circuit..).

Hygrostats are passive switching equipment without any electrical energy supply of their own (type FB...). The switching function is performed mechanically. The integrated switches are within a circuit designed as intrinsically safe by using a switching module (type EXL-IRU-1). The switching module should be installed in the safe area. The output contact can be used for sequence functions (relays, contacts, direct circuit..).

For monitoring air filters in hazardous areas, only passive differential pressure switches (type DBK...) can be used. The switching function is mechanical and is an intrinsically safe (IS) circuit that is supplied via a switching module (EXL-IRU-1). The switching module must be installed in the safe area. The output function can be used for switching relays, contacts etc.

For monitoring fans in hazardous areas, only passive differential pressure switches (DBK-...) or air paddle (type WFBK-...) can be used. The switching function is mechanical and is an intrinsically safe (IS) circuit that is supplied via a switching module (EXL-IRU-1). The switching module must be installed in the safe area. The output function can be used for switching relays, contacts etc. Switching modules to indicate fan failure, are delivered with integrated time running relay with delay on start up.

For monitoring fans contact less in hazardous areas, only inductive sensors (NBW-...) can be used. The switching function is mechanical and is an intrinsically safe (IS) circuit that is supplied via a switching module (EXL-IRU-1). The switching module must be installed in the safe area. The output function can be used for switching relays, contacts etc. Switching modules to indicate fan failure, with integrated time running relay with delay on start up, monitor the fan shaft rotation via a inductive sensor.

For frost protection in hazardous areas you can use a frost thermostat (type TBK-...)
in the duct together with a switching module ( type EXL-IRU-1). The passive sensor in the hazardous area is connected via an intrinsically safe circuit (IS) to the switching module , mounted in the safe area. The output contact can be used to follow up functions (relays, contacts, ect…).