Aquametro Oil & Marine CONTOIL VZF II, Mounting And Operating Instructions

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40
Limiting output
Setup menu: function for Output1 or Output2
Time
Q Lim
min
Q Lim
max
active
active
inactive
inactive
% of Q Lim
% of Q Lim
Flow
rate
Hysteresis
Hysteresis
NO NC
active
inactive
Work State
The function Limit allows you to set an alert whenever
predefined flow rates are exceeded.
Signal behavior:
Limit defines upper (Q Lim
max
) and lower (Q Lim
min
) flow rate
thresholds which, when exceeded, activate a switch (alert).
In order to prevent oscillating between active and inactive
states when the flow rate fluctuates about a threshold,
hysteresis bands (see adjacent diagram) can be defined in
which the switch will remain active once it has been
triggered to this state. When the flow rate passes below or
above these bands, the switch will be deactivated.
The hysteresis bands are calculated as a percentage of the
threshold values (Q Lim).
The switch can be used for remote control or alarm systems.
Parameters that can be set:
Lower flow rate
[LIMIT MIN]
: QLim
min
≥0 (factory setting: Qmin)
Upper flow rate
[LIMIT MAX]
: QLim
max
≤Q
max
(factory setting: Qcont)
Hysteresis
[HYST]
: 0...9 % (factory setting: 1 %)
The switches that are activated by the above parameters can be set to NO (Normally Open) or to
NC (Normally Closed). This choice is dependent on your needs.
Limit switch [NO] : Contact closes when the limits are exceeded .
Limit switch [NC]
: Contact opens when the limits are exceeded.
Example:
If the limit
[LIMIT MIN]
is set to 100l/h and
[HYST]
is set to 5%, then the hysteresis is 5 % of
100 l/h or 5 l/h. This means that as soon as the flow rate rises above 105 l/h the switch will be
deactivated if it is active.
If the limit
[LIMIT MAX]
is 200l/h and
[HYST]
is set to 5%, then the hysteresis is 5 % of 200
l/h or 10 l/h. If the switch is active then it will be deactivated as soon as the flow falls below
190 l/h.