Endress+Hauser Prosonic S FMU90 - The Function Test Submenu

The "relays/controls" menu
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5.3.4 The "function test" submenu
The function test is used to avoid incrustations which may occur if pumps are switched off for a long
time. If a pump has not been running for a defined time (max downtime), it is automatically
switched on for a short time (max test time).
!
Note!
The function test affects all pumps, even the standby pump.
"function test N" ( N = 1 or 2)
"function test"
Use this parameter to switch the automatic function test on and off.
Selection:
• off (default)
•on
"max. downtime" und "max. test time"
These parameters define when and how long a pump is switched on for the function test:
If a pump has not been running for the "max. downtime", it is switched on (even if momentarily
other pumps are running).
It is automatically switched off after the "max test time".
Default:
• max. downtime: 0h
• max. test time: 60 s
"switch on point" and"switch off point"
These parameters define a condition for the function test. A pump is only switched on for the
function test, if these conditions are met. Details depend on the relative position of the switching
points:
• switch on point > switch off point ("Emptying")
The function test is only performed if the level is above the switch on point.
If the level falls below the switch off point, the function test is terminated, even if the "maximum
test time" has not yet elapsed.
• switch on point < switch off point ("Filling")
The function test is only performed if the level is below the switch on point.
If the level rises above the switch off point, the function test is terminated, even if the "maximum
test time" has not yet elapsed.
Default:
• switch on point: 20%
• switch off point: 10%
⇒
function test 1 R1602
function test:
max downtime:
switch on point:
switch off point: