Et: Exchange Time; Cf: Carrier Frequency; Ac: Acceleration; Ae: Enabling The Anti-Blocking Function - DAB MCE-150/P Installations- Und Wartungsanleitungen

Example 2:
A pump set comprising 2 inverters (N=2 detected automatically) of which all inverters are active and
simultaneous (default setting NA=N and NC=NA) and one as reserve (IC=reserve on one of the two inverters).
The effect is as follows: the inverter not configured as reserve always starts up first; if the pressure reached is
too low, the second inverter, configured as reserve, also starts up. In this way, the use of one inverter in
particular is preserved (the inverter configured as reserve), but is always available as a support when
necessary in the event of increased hydraulic loads.
Example 3:
A pump set comprising 6 inverters (N=6 detected automatically) of which 4 are set as active (NA=4), 3
simultaneous (NC=3) and 2 as reserve (IC=reserve on two inverters).
The effect is as follows: a maximum of 3 inverters start up simultaneously. Operation of the 3 inverters enabled
for simultaneous mode is implemented in rotation between the 4 inverters to remain within the maximum
operating time of each ET. In the event of a fault on one of the active inverters, no reserve unit is started up
as no more than three inverters can be started up at a time (NC=3) and there are still three active inverters
present. The first reserve unit intervenes only when one of the remaining three has a fault; the second reserve
is started up when another of the three (including the first reserve) has a fault.
6.6.9

ET: Exchange time

This sets the maximum continuous operating time of an inverter within a group. It is only applicable on pump
sets with interconnected inverters (link). The time can be set to between 10 s and 9 hours, or to 0; the factory
setting is 2 hours.
When the time ET of an inverter has elapsed, the system starting order is re-assigned so that the "expired"
inverter is set to minimum priority. This strategy aims at reducing use of the inverter that has already been in
operation, and to balance operating times of the various units in the group. Despite assignment as the last unit
in the starting order, if the hydraulic load requires intervention of this specific inverter, it is started up to
guarantee adequate system pressure.
The starting priority is re-assigned in two conditions, according to the time ET:
1) Exchange during pumping process: when the pump is active continuously through to exceeding the
maximum absolute pumping time.
2) Exchange on standby: when the pump is on standby but 50% of the time ET has been exceeded.
If ET is set to 0, exchange occurs on standby. Each time a pump in the group stops, a different pump will be
activated on restart.
If the parameter ET (maximum working time) is set to 0, exchange occurs on each restart, regardless
of the effective working time of the pump.

6.6.10 CF: Carrier frequency

This sets the carrier frequency of the inverter modulation. The value set as default, is the correct value in most
cases, and therefore modifications are not recommended unless fully aware of the changes made.

6.6.11 AC: Acceleration

This sets the speed of variation with which the inverter varies frequency. This acts both on the start-up phase
and during control. In general, the pre-set value is optimal, but in the event of problems during start-up or HP
errors, it can be modified or reduced as required. Each time this parameter is modified, it is advisable to check
that system control is still efficient. In the event of problems of oscillation, lower the GI and GP gain values;
see paragraphs 6.9.4 and 6.6.5. A reduction to AC will slow down the inverter.

6.6.12 AE: Enabling the anti-blocking function

This function serves to avoid mechanical blockages in the event of prolonged disuses; it acts by periodically
activating the pump in rotation.
When this function is enabled, every 23 hours the pump complete an unblocking cycle lasting 1 minute.
ENGLISH
116