EVCO c-pro nano CHIL - Manual (Page 104)

C-PRO NANO CHIL AND C-PRO MICRO CHIL – APPLICATION MANUAL
Pag. 104
6.6 Compressor Management
The program is capable of managing up to a maximum of 3 compressors of the same power for each
circuit, thus 6 compressors in total. To each compressor digital inputs for protection devices can be
associated, as well as digital outputs for ON/OFF switching.
Switching ON/OFF is guaranteed by lateral-band or neutral-zone thermal regulation (see previous
chapter) and by some timings which protect the various starting points.
6.6.1 Compressor statuses
To each compressor, an operating status is associated, which is visible from the relative LED or in
the status template from the main menu. A compressor can take on the following statuses:
- Disabled: The compressor has not been configured, the display shows “dIS”.
- On: The status display shows “On”.
- Waiting to switch ON: The compressor is waiting for protection timings, before switching
ON. The status display shows “tOn”.
- Off: The status display shows “Off”.
- Waiting to switch OFF: The compressor is waiting for protection timings, before switching
OFF. The status display shows “tOFF”.
- Alarm: The compressor is in alarm status. The status display shows “ALAr”.
- Manual: The compressor is in manual operating mode. The status display shows “MAnU”.
In the maintenance operator menu, via parameters PM01, PM02, PM03, PM04, PM05 and PM06, it
is possible to read the number of operating hours of the corresponding compressors. To zero these
hours when required, it is sufficient to enter a “0” value using the ENTER key.
6.6.2 Rotation of compressors
Rotation of compressors is a procedure which enables balancing – as far as possible – of the number
of operating hours and start-ups of each compressor.
In the case of twin circuits, rotation must manage – whenever possible – the distribution of circuit
compressor requests in such a way as to privilege a balanced operation of both circuits.
Rotation does not affect any compressors in alarm status or manual operation mode, and is capable
of dynamically switching ON other compressors, in case one or more of them should be in alarm
status.
Via parameter PC01, the program is capable of managing 4 types of rotation: FIFO, LIFO, FIFO +
number of hours, LIFO + number of hours.
1) FIFO
This method follows the “First In First Out” logic, i.e. the first compressor to be switched on will
have to be the first to be switched OFF again. This operating logic could initially lead to a great
difference in the number of operating hours between the various compressors, but, after the initial
phase, the hours should more or less equalise.
This type of rotation has a peculiarity in cases where not all configured compressors within the
plant are switched ON; indeed, if for example the first compressor is switched ON and then OFF
again, the next compressor to be switched ON will be the second one. The last compressor to be
switched OFF is stored in memory, then the next compressor in the sequence is switched ON, so as
to avoid always using the same compressor, thus exploiting in a better manner all configured
elements.