Wilo Control MR-Lift - Level Measurement; Test Run Without Pump

8
English
Therm.1
Switches the pump off after
exceedingthepermissible
temperature value. After
cooling down the pump is
readytowork(chapter3).
Therm.2
Switches the pump off after
exceedingthepermissible
temperature value. The
pump can be restarted after
cooling down the pump and
after the failure has been
accepted(chapter3).
If no thermal protection is
connected to terminals 21,
22, the terminals shall be
bridged.
2.2.2. Control and signal circuit terminals
Connectionterminalsof:
• oatswitches
• thermal protections
• externallevelsensor
NOTE!
All connections must be
made at
non-potential status. De-
livery of external voltage
to any of the connectors
may result in damage to
the controller.
Alarm relay contact termi-
nals:
• terminals1,2–12VDC
potential contacts
• terminals3to6–
non-potential contacts
2.3. Level measurement
MR-Lift is equipped with 2 methods for measur-
ingthelevelofliquidinthetank–linearmeas-
urement(internalsensororexternalpressure
sensor4-20mA)andoatswitches.
2.3.1. Linear level measurement
Measurement of water column pressure in the
range 0 - 100cm.
If the pump is operating in an explosive atmos-
phere, the pump station must be equipped with a
oatindicatinglackofliquid.Removethejumper
from the NLinputandconnecttheoat.Incase
of lack of liquid the display shows “No liquid”, the
alarm will sound and the pump will be stopped.
When using a screw pump the pump station also
mustbeequippedwithaoatindicatinglackof
liquid.
2.3.1.1. Internal sensor
Connectpressurelineofdiameter8x6mmto
the metal connector on the right of the device.
Required pressure can be obtained by use of one
ofthefollowingmethods:
1. Closed cast iron bell hung in the tank.
2. Spargepipemethod:tubeorironbellplacedin
the tank, supplied with bubbles generated by the
membrane pump.
2.3.1.2. External pressure sensor 4-20mA
Externaltwo-wiresensormustbeconnectedto
terminals30(+)i31(-).Thesensorispoweredby
stabilized voltage of 20V.
2.3.2. Float switches
Float inputs work as normally open.
Operation with 2
oatswitches
Operation with 3
oatswitches
Operation with 3
oatswitcheson
a single wire
Choosethe“oats”optionfromthelevelmeas-
urement menu. The display shows the status of all
threecontacts:NL,SW,HL.TheSWoatturnsthe
pump on and off and its hysteresis determines
the difference between the level of turning the
pumponandoff.TheHLoatindicatesahigh
level.TheNLoatindicatesalackofliquid.Ifthe
pumpisoperatinginanexplosiveatmosphere,
thepumpstationmustbeequippedwithaoat
indicating lack of liquid. When using a screw
pump the pump station also must be equipped
withaoatindicatinglackofliquid.
Ifaninappropriatestatusoccurs(e.g.NL=0,
SW
=1),thealarmisturnedonandthefollow-
ingmessageisdisplayed:“Floatswitcheswrong
sequence”. Check the status, remove its cause
and accept the alarm. This alarm does not result
in blocking the pump’s start and the pump will
workdespitefailuresofoatswitches.TheHL
oatturnsthepumponimmediately,regardless
ofoatsSW. It must be noted that the high level
oatswitchterminalisalwaysactive,evenif
another method of level measurement has been
chosen from the menu.
2.4. Test run without pump
To check working of the control system with no
pump connected, proceed in accordance with the
followinginstructions:
1. Turnthepowersupplyon(itisenoughtoconnect
L1,N,PE).
2. Fromthemenuset“Maximumcurrent”to0.0A.
Otherwise an alarm will occur and the message
“No load” will be displayed.
3. From the menu turn off the “Therm.protect1”.
Otherwise an alarm will occur and the message
“Thermal fault 1” will be displayed.
4. Close terminals 21, 22. Otherwise an alarm will
occur and the message “Thermal fault 2” will
occur.