English (US)
20
10.3.5 Buttons on pump
The operating buttons
and on the control panel can be set
to these values:
•
Active
•
Not active.
When set to
Not active
(locked), the buttons do not function.
Set the buttons to
Not active
if the pump should be controlled via
an external control system.
10.3.6 Pump number
A number between 1 and 64 can be allocated to the pump. In the
case of bus communication, a number must be allocated to each
pump.
10.3.7 Digital inputs
The digital inputs of the pump (terminal 1, fig. 4, 7 or 12) can be
set to different functions.
Select one of the following functions:
•
Min. (min. curve)
•
Max. (max. curve)
•
External fault
•
Flow switch
•
Dry running
(from external sensor) (only three-phase pumps).
The selected function is activated by closing the contact between
terminals 1 and 9, 1 and 10 or 1 and 11. See figs 4, 7 and 12.
See also section
13.2 Digital input
on page 26.
Min.:
When the input is activated, the pump will operate according to
the min. curve.
Max.:
When the input is activated, the pump will operate according to
the max. curve.
External fault:
When the input is activated, a timer will be started. If the input is
activated for more than 5 seconds, the pump will be stopped and
a fault will be indicated. If the input is deactivated for more than
5 seconds, the fault condition will cease and the pump can only
be restarted manually by resetting the fault indication.
Flow switch:
When this function is selected, the pump will be stopped when a
connected flow switch detects low flow.
It is only possible to use this function if the pump is connected to
a pressure sensor.
If the input is activated for more than 5 seconds, the stop function
incorporated in the pump will take over. See section
10.3.8 Stop
function
on page 20.
Dry running
(only three-phase pumps):
When this function is selected, lack of inlet pressure or water
shortage can be detected. This requires the use of an accessory,
such as these:
• a Grundfos Liqtec
®
dry-running sensor
• a pressure switch installed on the suction side of a pump
• a float switch installed on the suction side of a pump.
When lack of inlet pressure or water shortage (
Dry running)
is
detected, the pump will be stopped. The pump cannot restart as
long as the input is activated.
10.3.8 Stop function
The stop function can be set to these values:
•
Active
•
Not active.
When the stop function is active, the pump will be stopped at very
low flows. The controller will stop the pump to protect the pump
as follows:
• avoid unnecessary heating of the pumped liquid
• reduce wear of the shaft seals
• reduce noise from operation.
Fig. 29
Difference between start and stop pressures (
'
H)
˂
H is factory-set to
10 % of actual setpoint
.
˂
H can be set within the range from 5 % to 30 % of actual
setpoint.
Low flow can be detected in two different ways:
1. A built-in "low-flow detection function” which functions if the
digital input is not set up for flow switch.
2. A flow switch connected to the digital input.
1. Low-flow detection function
The pump will check the flow regularly by reducing the speed for
a short time. If there is no or only a small change in pressure, this
means that there is low flow. The speed will be increased until the
stop pressure (actual se 0.5 x
˂
H) is reached and the
pump will stop. When the pressure has fallen to the start pressure
(actual setpoint - 0.5 x
˂
H), the pump will restart.
When restarting, the pumps will react differently according to
pump type:
Single-phase pumps
The pump will return to continuous operation at constant pressure
and the pump will continue checking the flow regularly by
reducing the speed for a short time.
TM
00
77
44
18
96
Stop pressure
˂
H
Start pressure
H
Q
DBP-1 - GRUNDFOS PUMP CRE - 99392005
Summary of Contents for SPKE Series
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