Jesco MEMDOS E, Operation Manual

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3. Function
Motor-driven diaphragm dosing pumps of the MEMDOS series are used in industry in the process engineer-
ing sector, and in water treatment and wastewater processing.
The MEMDOS E and MEMDOS DX are available in two overall sizes:
• Size 1: max 160 l/h delivery capacity
• Size 2: max 380 l/h delivery capacity
MEMDOS E
The MEMDOS E is used where no control is required for constant dosing. In this case, the power supply is
connected directly to the motor terminal box. To adapt the dosing capacity, either the stroke length can be
adjusted manually from 0 to 100%, or the motor speed can be controlled by means of a separate frequency
converter. The MEMDOS E is optionally available with electric remote adjustment of the stroke length (ATE).
The MEMDOS E can be operated in Zone 1 hazardous areas if the corresponding drive is taken into consid-
eration. Further information can be found in section 12.
MEMDOS DX
The "smart" MEMDOS DX is used where the dosing pump is to be integrated in controls or control circuits.
The MEMDOS DX allows adaptation to a large variety of different control signals and system monitoring
equipment. The signals required for external activation of the dosing pump can be from simple potential-
free closing contacts of water meters or controllers, or analogue 0/4...20 mA signals. For contact actuation
(pulse control), the stroke frequency can be adapted by division or multiplication. For internal operation (own
stroke), the dosing pump can be adjusted continuously between 0 and max. 142 strokes/min, depending on
version.
Principle of operation
a
Diaphragm
b
Diaphragm rod
c
Return spring for suction stroke
d
Tappet plate
e
Drive eccentric
f
Stroke limit eccentric
Like the roller bearings, the worm gear set of
the single-speed gear runs in an oil bath. Dosing
takes place when movement of the drive eccentric
e
causes movement of the diaphragm rod
b
.
The suction stroke is produced by the return
movement due to spring force. Stroke length is
adjusted by limiting the tappet return movement
using a manually adjustable eccentric disc as the
end stop (stroke limiting eccentric
f
). The adjust-
ment range is from 0 to 100%.
a b c d
e
f
min.
max.
max.
8
| Operation & Maintenance Instructions | Function