DAB MCE-11/P, Инструкция по установке и обслуживанию, Страница: 103 / 600

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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 between 10 s and 9 hours; the default 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.
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 at which the inverter increases frequency. This is more significant during
start-up than during regulation. In general the default value is the optimal setting, but in the event of
problems with start-up this value can be modified.
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.