Grundfos DDI 209, Инструкция по установке и эксплуатации

Страница: 38 / 76

En
gl
is
h (
G
B)
38
9.2.6 Remote on/off
The pump can be switched off remotely (e.g. from a
control room).
•
If switched off remotely, the pump does not
respond to any input signals or to operator input.
Exception: The pump can still be stopped and
deaerated manually.
• "Stop" lights up in the display.
• The yellow LED lights up.
• When switched on remotely, the pump returns to
the state it was in before it was switched off. If,
for example, the pump was previously in "Stop"
mode, it returns to this mode once it is switched
on.
9.2.7 Memory function
Contact signals, which cannot be processed
immediately, can be stored and subsequently made
available to the pump for processing. A maximum of
65,000 contact signals can be stored.
•
Without memory: If the pump is running when a
contact signal is received, the signal is ignored.
The pump performs the current dosing, then it is
again ready to receive new contact signals, i.e. it
rejects excess contacts.
• With memory: If the pump is running when a
contact signal is received, the signal is stored in
the memory. First, the pump performs the current
dosing, then it processes the contact signals from
the memory.
The contents of the memory are deleted:
•
by switching off the power supply
• by switching the operating mode.
The contents of the memory are not deleted:
•
by actuating the remote on/off contact
• by pressing the "Start/Stop" button
• by continuous operation.
9.2.8 Flow Monitor
The pump can be equipped with a pressure sensor
(Flow Monitor pump option).
Based on the pressure measured by the sensor and
on the motor position, an indicator diagram is
created. Possible dosing faults or the exceeding of
the permissible counter-pressure are detected
reliably and indicated by the display or the error
message output.
The following errors are recognised:
• Pressure exceeded (the pump is stopped and
restarts automatically when the pressure
decreases).
• Dosing error (the pump doses 30 % to 100 % less
due to a leaking discharge valve or suction valve,
a clogged suction line or an air bubble in the dos-
ing head).
The dosing controller and dosing control functions
can be switched on and off independently of each
other. It is always possibly to display the pressure
that has been measured during operation whenever
the pressure sensor is connected.
9.3 Signal outputs
The control unit has the following signal outputs,
e.g. in order to return a signal to the control room.
9.3.1 Current signal output
The current flow rate of the pump is output as a
current signal.
• Current output 0-20 mA in the following mode:
– Current control 0-20 mA.
• Current output 4-20 mA in the following modes:
– Current control 4-20 mA
– Manual
– Contact
– Batch dosing with manual/contact start
– Timer with manual/contact start.
9.3.2 Error signal
Used to return various error states to the control
room.
9.3.3 Stroke signal / pre-empty signal /
pulse input
Depending on the relay setting, the contact output
receives a signal in these cases:
•
for each complete stroke of the pump, or
• a pre-empty signal input, or
• each pulse input at the pump.
To set the relay, see section 9.7.1 Modifying the
switch assignment .
Note
The memory function can be enabled
and disabled in the second function
level.
Caution
Depending on the operating
conditions, it may be impossible to
detect dosing errors which are caused
by leaking suction valves!
Note
For information about operating the
pump with the Flow Monitor, see
section 9.10 Flow Monitor.
Note
To use the control signal output, see
section 9.9 Current signal control
0-20 mA / 4-20 mA.
Note
The current output is linear between
4 (0) mA at flow rate = 0 and 20 mA at
maximum flow rate Q
max.
(default
setting) or the corresponding
weighting value pair.