Fire detection for suppression system FDU WRS LK
The fire detection unit FDU LK could be assembled with any and operating every electric extinguishing. If it senses over temperature it releases the electric power of 24V DC 10 W to the magnetic valve. Lower warning temperature and pressure check of the agent cylinder could be set voluntary. The release by signals of electric linear sensors or temperature switches is optional as well as manual release.
Green screen displays
In the following example two temperature sensors are connected and are reading
the ambient temperature. Sensor 3 and 4 are shunted by a jumper and therefore
not active. The number of transferred messages (225) to the server is listed in parentheses.
Flashing yellow screen displays
If no sensor or jumper is connected, then the display shows < Err! >
as it is shown for example on the next photo at location T4.
If the background is yellow there is a problem, which is determined not only by the
missing sensors but either the disconnection of the solenoid or pressure sensor or it
is detecting low pressure of the agent container as well as a short circuit. A warning
message appears even if only one of the following momentums exists.
The terminals for the pressure switch and the solenoid coil are strong spring connectors
at the printed circuit board. Here is a sketch of the wire diagram thereof.
A cable set could be supplied on request.
However, this feature requires the assembly of two resistors of 500 Ω and 1 kΩ 1 W
connected direct to the terminals of the pressure switch as shown. The wiring of the
terminal to the solenoid of the magnetic valve is also monitored. The following example
of the display shows everything is in good order except the pressure sensor, which
perceives no pressure indication.
Flashing red screen displays
Now all 4 sensors are connected to the PCB, one measures the temperature
of 138 °C, which means fire in the engine compartment and therefore the
24 VDC 10 W power output was released to the solenoid and the fire alarm
is displayed on the screen. The alarm and a lower warning temperature could
be freely set.The indication board prevents optical and acoustical signals to the
driver. As an option the separate horn could be connected amplifying the noise to
90 dB in case of fire. The time of sounding could be set voluntary.
No connection or short circuit
No connection, low pressure or short circuit
sensor not in place or missing shunt
Easy Assembly of FDU-SNS in
the engine compartment
1) Attach the body with cable ties to the top of the compartment and supply 24 VDC. Brown (+).
2) Check the distance to the hot spots and cut a ½ inch Marten hose to this length and push the free end of the SEH sensor through it.
3) Press the sensor head completely into the Marten hose.
4) Lose the nut of the cable gland and insert the other end of the spiral hose.
5) Plug the free connector into the corresponding socket at the circuit board and remove the black shunt.
6) Screw the cable gland nut and close the cover of the body water tight (lP 65). Check that the rubber gasket in the lid of the body will not be damaged.
7) Place the sensor head above the dangerous hot spots .
Detector head is very sensitive for short response.
Handle with care.
Attach the SNS body with cable ties at the top of the engine
compartment and supply 24 VDC to the cable. Brown wire (1) for plus blue wire (2) for ground. Check the bar code is visible.
• Standard type has 5 sensors
• Option up to 6 engine boxes
• Up to 30 fire sensors could
communicate with the display
Fire detector SNS
We like Blackay and
Rotarex Compact Line Systems