Carel FLSTDMFC0A, Manual

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FLSTDMFC0A pCO² refrigeration system
cod. Carel +030221991 rel. 1.0 dated 27/07/01
7
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Can be configured with or without capacity-control
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number of capacity-control steps
capacity-control step times
compressor times
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The compressors are managed by the unit based on Set Point and a differential, which can be set on the screen
(M_SETPOINT10, SET branch) and on the value read by the inlet probe.
In the default configuration, dead zone control is activated - which can be set on the screen (M_MANUF220, manufacturer
branch) - with FIFO rotation (M_MANUF220, manufacturer branch), respecting the various time settings (see the corresponding
paragraph).
For a description of dead zone or proportional band operation, please see the following paragraph.
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If the control is configured with an inverter, no capacity-control can be used
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enable inverter
inverter set point
inverter step
minimum compressor inverter opening
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The compressor inverter can be activated on the screen (M_MANUF115 manufacturer branch), if no capacity-control steps are
configured.
A lower limit can be set for the inverter (M_MANUF240 manufacturer branch),
The inverter is managed as follows:
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The inverter is set on the first compressor, which will always be the first on and the last off.
The control requires the setting of a differential (DZNI) for the control of the inverter (M_SETPOINT35 branch SET) from the
inverter Set Point (SP) and the amount to increase the value by each second.
The output of the inverter of compressor no. 1 starts increasing when the reading of probe a1 exceeds the inverter Set Point + the
differential. A decrease occurs when the reading of probe a1 is below the value of the Set Point.
In the zones between the SP and SP + DZNI, the output of the inverter is not changed. The output of the inverter is
increased/decreased every second, by the value defined as the inverter step (M_SETPOINT35, SET branch)
Caution:
when the compressor inverter is enabled and is controlled outside of the dead zone, the compressors are started in the
following way:
- compressor 1, which is managed by the inverter, is
activated as soon as there is a start request;
- if the request remains, the output of compressor 1 inverter
is increased;
- if the request is still present, and the output of the inverter
reaches 10 Volts, the other compressors are requested, one
at a time, with rotation (if selected) and respecting the time
settings.
For deactivation , the following occurs:
- the output of the inverter is decreased;
- when the output of the inverter reaches 0 Volt, the other
compressors stop, one at a time, respecting the time
settings and rotation;
- the last compressor to stop is no. 1.
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The control requires the setting of a set point and a differential
(M_SETPOINT20-50, SET branch). When the value measured
by the inlet probe is less than or equal to the value of the inverter
set point, the output of the inverter is 0 Volt. As the value
measured by probe B1 moves away from the set point, the
analogue output is increased in proportion to the deviation, until
reaching 10 Volts, when the value measured is greater than or
equal to the inverter set point + differential.
SP
RP
DZNI
0 V
10 V
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SP
0 V
10 V
RP
V
BLI
2
1
3
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