Xylem HYDROVAR (HV2.1 - 3.45) - Manual (Page 55)

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9.22.3 Enable sequence control
With this parameter you can select the desired start-value for the following pumps. If a pump
in the system reaches this release-frequency and the system pressure drops below the
“Required value” - “actual value decrease”, the next pump will start.
ENABLE SEQ. CTL.
48.0 Hz
Adjustable from 0.0 Hz to 70 Hz.
In general this release frequency should be set 1-2 Hz lower than the max. frequency.
If the following pump(s) are not necessary to cover a higher demand, but want to be used
for automatic change over to provide even wear or in case of a failure, the release frequency
must be set higher than the max. frequency.
This parameter is used also to start a fixed speed pump, when Simple Multicontr. is set.
When this frequency level is reached, the dry contact of the relay X2/5 – X2/6 will be closed.
With the parameter Stop Delay Fmin (chapter 9.11), you could select a delay time.
Press the ¾ button to change to the next parameter
9.22.4 Switch Interval
This parameter allows an automatic change over of the master pump and the following
pumps, in order to provide even wear and achieve even operating hours of the pumps.
This is the interval of time after which the starting sequence of the pumps is automatically
switched in order to ensure the uniform use of all the pumps available (the interval is based
on the operating time of the pumps, MOTOR HOURS parameter).
SWITCH INTERVAL
12 hours
Adjustable between 1 and 100 hours.
If an interval of more than 100 hours is selected, the automatic changeover is disabled.
Manual change of the master pump in the 1
st display with the Ï - button.
Press the ¾ button to change to the next parameter
9.22.5 Source of required value
SOURCE REQ. VALUE
OFF
By using a 2 nd required value in a multi-pump system,
there are different options to set the source of this value.
For selecting you have to choose the desired pump-address which should be the source of the
required value. Following adjustments are possible: OFF, ADR1, ADR2, ADR3 and ADR4
If an additional analogue input is active, you have to enter the address where this input is
connected. If the right address is selected, the additional input is active for the whole system,
which means that only one input is necessary also for a multi-pump system.
At active Multicontroller or Synch. Controller mode, the active value (required value 1 or 2) is
shown in the centre of the display in the first line of the first window (see chapter 8c).
If “#” is shown in the second line of the display, the pump will work with a required value
from another pump in the multi-pump system. On the pump, which is the source of the
required value, no “#” is shown.
If the source of the required value is set to “OFF”, no 2
nd required value is used, or the source
for this value is always taken of the actual master.
Press the ¾ button to change to the next parameter