Min. Time And Max. Number Of Starts (4.2.1); Standby Pumps (4.2.3) - Grundfos Control DDD Montage- Und Betriebsanleitung

8.7.14 Min. time and max. number of starts (4.2.1)

Fig. 62 Min. time and max. number of starts
Description
The function limits the number of pump starts and stops per hour
for the complete system. It reduces noise emission and improves
the comfort of systems with mains-operated pumps.
Each time a pump starts or stops, CU 354 calculates when the
next pump is allowed to start/stop in order not to exceed the
permissible number of starts per hour.
The function always allows pumps to be started to meet the
requirement, but pump stops are delayed, if needed, in order not
to exceed the permissible number of starts per hour.
The time between pump starts must be between the minimum
time between start/stop, see section
start/stop (4.2.1), and 3600/n, n being the set number of starts
per hour.
Setting range
1 to 1000 starts per hour.
Setting via operating panel
• Settings > Pump cascade control > Max. number of starts/
hour.
1. Set:
• Min. time between start/stop.
• Max. number of starts/hour.
Factory setting
DDD-E: 200 starts per hour
DDD-EC, DDD-EF: 100 starts per hour.
This function has no influence on
(4.3.1)".
8.7.13 Min. time between
"Stop function

8.7.15 Standby pumps (4.2.3)

Fig. 63 Standby pumps
Description
The function makes it possible to limit the maximum performance
of the system, by selecting one or more pumps as standby
pumps.
If a three-pump system has one standby pump, maximum two
pumps are allowed to be in operation at a time.
If one of the two pumps in operation has a fault and has stopped,
the standby pump is started. The performance of the system is
thus not reduced.
The status as standby pump alternates between all pumps.
Setting range
The number of possible standby pumps in a system is equal to
the total number of pumps in the system minus 1.
Setting via operating panel
• Settings > Pump cascade control > Standby pumps.
• Set: Set the number of standby pumps.
Factory setting
The number of standby pumps is set to 0. The function is
disabled.
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