Grundfos CONTROL MPC Installation And Operating Instructions Manual page 38

Diaphragm tank size
Recommended diaphragm tank size [litres]
Pump type
-E
CRI(E) 3 8
CRI(E) 5 12
CRI(E) 10 18
CRI(E) 15 80
CRI(E) 20 80
CR(E) 32 80
CR(E) 45 120
CR(E) 64 120
CR(E) 90 180
CR(E) 120 180
CR(E) 150 180
Precharge pressure
Hydro MPC-E and -F: 0.7 x setpoint.
Hydro MPC-S: 0.9 x setpoint.
During each flow estimation (every 2 minutes), the estimating
function will disturb the discharge pressure by ±10 % of the
setpoint. If this disturbance is not acceptable, the stop function
must be based on direct flow measurement with a flowmeter or
flow switch.
The minimum flow rate can be set, i.e. the flow rate at which the
booster system changes to on/off control of the last pump in
operation.
If both a flowmeter and a flow switch are connected, the
changeover to on/off control is determined by the unit first
indicating low flow rate.
Setting range
On/off band: 5 to 30 %
Min. flow rate: 2 to 50 % of the nominal flow rate (Q
of the pumps. (Can only be set if direct flow
measurement by means of flowmeter has been
selected.)
Setting via control panel
System without flow switch or flowmeter
1. Mark the Settings menu with
2. Mark Secondary functions with
3. Mark Stop function with
4. Mark Activated with
The activation is indicated by a check mark in the box.
5. Mark On/off band with
6. Set the on/off band with
7. Mark Go to setting of flow stop parameters with
, and press .
Now the display below is shown.
Fig. 62 Stop parameters
38
-F -S
8 80
12 120
18 180
80 300
80 400
80 600
120 800
120 1000
180 1500
180 1500
180 1500
) of one
nom
.
or , and press
or , and press .
or , and press .
or .
or , and save with
8. Select one of the stop parameters with
with . If Customised settings are selected, the
parameters shown in fig. 63 must be set. See examples
below.
Fig. 63 Customised settings
Rule of thumb: Speed reduction = 2 x delta
Note
pressure for gradient.
Example 1: Increasing the stop limit, Q
• Increase the delta pressure for gradient.
• Reduce the delta time for gradient (pump stopped).
• Reduce the delta time for gradient (pump running).
• Increase speed reduction.
Parameter
Delta pressure for gradient
Delta time for gradient (pump stopped)
Delta time for gradient (pump running)
Speed reduction
Example 2: Reducing the stop limit, Q
• Reduce the delta pressure for gradient.
• Increase the delta time for gradient (pump stopped).
.
• Increase the delta time for gradient (pump running).
• Reduce speed reduction.
. Parameter
or
Delta pressure for gradient
Delta time for gradient (pump stopped)
Delta time for gradient (pump running)
Speed reduction
The stop limit depends on the tank size.
Note
min
Example of increased stop limit
min
Example of reduced flow limit
or , and save
(high flow limit)
Value
6 %
1.5 sec
2.0 sec
10 %
(low flow limit)
Value
3 %
15.0 sec
25.0 sec
6 %