EVCO c-pro mega RACK - Manual (Page 97)

C-PRO MEGA RACK & C-PRO GIGA RACK APPLICATION MANUAL
Page 97
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Flashes slowly if only one of the compressor and fan setpoints is altered.
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Remains on if both setpoints are altered by the time bands.
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Remains off if there is no condition.
To enter time band management, press and hold display key K2 for approx. 2 seconds.
6.7.4 Digital input setpoint alteration
For both compressors and fans, the program envisages the possibility of managing the compressor
DI secondary setPoint offset and fan DI secondary setPoint offset parameters, which, depending on
the digital input status (different for compressors and fans) sum an offset to the main setpoint in
order to allow variation. It is possible to set the digital input logic by altering the parameter Other
DI logic (PH19, itself a parameter relating to the digital input on/off logic).
To set this function, it is necessary to configure the parameter DI enabling secondary setpoint
(PH25) and set the position where the digital input relating to the compressors and relating to fans
will be connected. If this value is not set, the function will remain disabled.
6.7.5 Supervisor setpoint alteration
For both compressors and fans, the program envisages the possibility of managing the compressor
SUP secondary setPoint offset and fan SUP secondary setPoint offset parameters, which, depending
on the state of a variable set by the supervision protocol (different for compressors and fans) sum
the adjusted offset to the main setpoint in order to allow variation.
To set this function it is necessary to configure the parameter supervisor secondary setpoint
enabling (PH26) and the status enable by means of the exported variable. If this value is not set, the
function will remain disabled.
6.7.6 Manual operation
The program allows setting a manual compressor and fan function. In this state, devices do not
participate in rotations nor in the calculation of thermoregulation, however, they are sensitive to any
alarms.
Manual operation of devices is useful when functional tests must be conducted on the machine, in
order to test the integrity and correct operation of the mechanical components.
Compressors
Manual or other operation of the compressors is guaranteed by the parameter compressor enable:
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If set to the value “A” it defines the normal behaviour of the device
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If set to the value “M” it disables the compressor and switches it to manual operation.
A manually functioning compressor does not participate in regulations, and may be forced into the
number of steps it is capable of providing (even over its increments, where configured) by setting
the parameter compressor forcing (found in the Service -> Compressor forcing menu). The number
of steps a manually functioning compressor can provide is limited to the number of increments that
have been set during machine configuration.
As already mentioned, the compressor is, in any case, sensitive to alarms and the relevant
consequences.