Jesco FEDOS E 5, Руководство по эксплуатации

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7.5 Level monitoring
If a level monitor is connected, the jack plug has to be covered by a plastic sleeve in order to maintain the
protection class. The required sleeve is part of the level monitor (also in combination with a suction line).
With the level monitor connected, the dosing pump stops if the chemical level in the supply tank is low, in
order to prevent air bubbles from entering the suction line and the dosing head. The red LED is lit. As soon
as the level contact closes again, the dosing pump restarts.
The level sensor must be designed as a max. N.O. contact.
FEDOS is equipped with a 2-stage level monitor. When the first contact breaks (low level alert), the red LED
begins to flash. The dosing pump continues to operate. The fault signalling relay is actuated. The dosing
pump only stops when the second contact breaks (main alarm). The red LED is lit continuously.
The "low level alert" function is not available when using a 2-pin connector and a simple float switch.
NOTE!
A dummy plug (Part No. 29115) must be attached if a float switch is not connected. The dosing pump is
delivered with a dummy plug already attached. If a float switch is to be connected, the dummy plug has to
be removed before inserting the jack plug.
7.6 Pressure control and safety valves
Pressure control valves are used to optimise the dosing process. They are used:
• to increase the dosing accuracy in the case of fluctuating backpressure.
• when the dosing lines are long, in order to prevent excess delivery, since the accelerated medium
continues moving due to its own inertia even after the delivery stroke has ended.
• to prevent siphoning, if the supply pressure is higher than system pressure.
Pressure relief and safety valves are used for overload protection of the dosing pump and the associated
valves and lines. They prevent inadmissible pressure rises in the delivery side system of the dosing pump;
for example, if shutoff valves close while the pump is running, or if the injection nozzle is clogged.
7.7 Injection nozzle installation
Injection nozzles are used to inject the metered medium into the main flow, while at the same time acting
as non-return valve. The injection nozzle is usually mounted from the top into the main line. Mounting from
below is recommended only for media that have a tendency to crystallise, in order to prevent air bubbles
from being trapped in.
For media that tend to contaminate the injection nozzle, we recommend installing an injection nozzle that
can be shut off and removed for maintenance purposes.
a
b
a
Injection nozzle mounted from above,
b
Injection nozzle mounted from below (for media that tend to crystallise)
Installation | Operating Manual FEDOS E/DX |
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