Grundfos Control MPC-Serie Installationsanleitung Seite 39

8.7.16 Standby pumps (4.2.3)
Fig. 55 Standby pumps
Description
The function allows you 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 will be 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 the 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 zero. The function is
disabled.
8.7.17 Forced pump changeover (4.2.4)
Fig. 56 Forced pump changeover
Description
The function ensures that the pumps run for the same number of
operating hours.
In certain applications, the requirement remains constant for long
periods and does not require all pumps to run. In such situations,
pump changeover does not take place naturally, and forced pump
changeover may thus be required.
Once every 24 hours, CU 352 checks if any pump running has a
larger number of operating hours than pumps that are stopped. If
this is the case, the pump will be stopped and replaced by a
pump with a lower number of operating hours.
Setting range
You can enable and disable the function. You can set the hour of
the day at which the changeover is to take place.
Setting via the operating panel
• Settings > Pump cascade control > Forced pump changeover.
1. Select: Enabled.
2. Set: Time of day for changeover.
3. Select interval for pump changeover.
Factory setting
The function is enabled. The time is set to 03:00.
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