OSAKA
- USER MANUAL - B4U - v2 - PAG. 11
It also allows the display of the acronym "dF" ("dL" = Lb) during the
defrost and, after the defrost is finished, the message "Pd" will appear
until, after the defrost, the Pr1 temperature has not returned to the
set value. the last reading, or to the value ["SP" + "d"]) or when the
time programmed in parameter "dA" expires.
Otherwise ("dL" = oF), the display will show the temperature
measured by the Pr1 probe during a defrost.
5.9 - EVAPORATOR FAN CONTROL
The evaporator fan control works through the output configured as
"Fn" depending on certain control states of the B4U and the
temperature measured by the evaporator probe (probe configured as
"EP").
The parameters related to the fan control functions are found in the
"-Fn" folder.
If the evaporator probe is not used or is in error, the output configured
as "Fn" is activated only according to the parameters "tn", "tF" and
"FE".
With the parameters "tn" and "tF" it is possible to set the behavior of
the evaporator fans when the regulation output configured as "ot"
(compressor) is deactivated.
When the output "ot" is deactivated, it is possible to make the output
configured as "Fn" continue to operate cyclically according to the
times programmed in the parameter "tn" (activation time of the
evaporator fan at compressor stop) and " tF "(evaporator fan
deactivation time at compressor stop).
When the compressor stops, the B4U keeps the evaporator fans on
for time "tn", then turns them off for time "tF" and so on until the output
"ot" remains off.
When programming "tn" = oF, the “Fn” output will be deactivated
when the “ot” output is deactivated (the evaporator fans are off when
the compressor is stopped or the fans are running together with the
compressor).
By programming "tn" at any value and "tF" = oF, the "Fn" output will
remain activated even when the "ot" output is deactivated (the
evaporator fans are on when the compressor is stopped).
The "FE" parameter allows setting whether the fans should always
be on regardless of the defrost status ("FE" = on) or turn off during
defrost ("FE" = oF).
In the latter case, by setting the time in the "Fd" parameter, it is
possible to delay the restart of the fans after the end of the defrost.
When this delay is active, the FAN LED flashes to indicate the delay
in progress.
When the evaporator probe is used for the fan, it is conditioned by
the parameters "tn", "tF and" FE, and acts as a temperature control.
In fact, it is possible to configure the fans to deactivate when the
temperature measured by the evaporator probe is higher than the
value programmed in the "FL" parameter (temperature too high) or
also when it is lower than the value programmed in the "LF"
parameter. "(very low temperature).
Associated with these parameters there is a programmable
differential in the parameter "dF"
.
Note: Special attention should be paid to the correct use of the
temperature-based fan control functions, since in a typical
refrigeration application, the evaporator fan stops due to thermal
change.
Remember that the operation of the evaporator fans can also be
conditioned by the "door open" function of the digital inputs.
5.10 - ALARM FUNCTIONS
The parameters related to the fan control functions are found in the
"-AL" folder.
The B4U alarm conditions are:
- Probe error: "E1", "-E1", "E2," -E2 "," E3 "," -E3 "
- Temperature alarm: "H1", "L1", "H2", "L2"
- External alarms: "AL", "Pr", "HP", LP "
- Open door alarm: "oP"
The alarm function acts on the internal buzzer, if it is configured with
the "Bu" parameter, and on the desired output, if it is configured with
the "o1", "o2", "o3", "o4" parameters.
The buzzer can be configured to signal alarms by setting the
parameter "Bu" = 1 or 3 or 4 and always functions as an alarm that
can be silenced. This means that, when activated, it can be
deactivated by briefly pressing any key.
Alarms can be configured to signal them by configuring the outputs.
The possible alarms that can be configured are the following:
= On - When you want the output to activate in alarm condition and
to be able to deactivate (silence) manually by pressing any key on
the B4U.
= AL - When the output is desired to activate in alarm condition but
cannot be manually deactivated and therefore deactivates only when
the alarm condition is canceled (typical application for a light signal).
= An - When you want the output to activate in alarm condition and
to remain active even when the alarm condition has ceased (alarm
memory). Therefore, deactivation (stored alarm acknowledgment)
can only be performed manually by pressing any key when the alarm
status has been cleared (typical application for light signal).
= -t - When the operation described as En is desired but with inverse
operation logic (output activated in normal condition and deactivated
in alarm condition).
= -L - When the operation described as AL is desired but with inverse
operation logic (output activated in normal condition and deactivated
in alarm condition).
= -n - When the operation described as An is desired, but with inverse
operation logic (output activated in normal condition and deactivated
in alarm condition).
5.10.1 - TEMPERATURE ALARMS
The B4U has two temperature alarms, each with fully configurable
maximum and minimum thresholds.
The temperature alarm functions act according to the measurements
of the probes, what is configured in parameters "1y" and "2y", the
alarm thresholds programmed in parameters "1H" and "2H"
(maximum alarms), "1L" and "2L" (minimum alarms) and the relative
differentials "1d" and "2d".
Through the parameters "1y" and "2y" "it is possible to program the
alarm thresholds" 1H "," 2H "," 1L "," 2L "and they must be considered
as absolute or relative to the Set Point.
Depending on the desired operation, the parameters "1y" and "2y"
can be configured with the following values:
= 1:
Absolute referring to Pr1 with message display (HL).
= 2:
Relative to Pr1 with message display (HL).
= 3:
Absolute referring to Au probe with message display (HL)
= 4:
Relative to Au probe with message display (HL).
= 5:
Absolute referring to cd probe with message display (HL). = 6:
Absolute referring to Pr1 without message display.
= 7:
Relative to Pr1 without message display.
= 8:
Absolute referring to Au probe without message display.
= 9:
Relative to Au wave without message display.
= 10:
Absolute referring to cd probe without message display.
By means of some parameters it is possible to delay the notification
of these alarms. These parameters are:
"1P" and "2P" - are the delay times of the temperature alarms at the
start of the B4U, which if there are alarms at start-up, they will wait
for the time programmed in these parameters to pass.
If there are no alarm conditions at connection, the relative time "1P"
and "2P" will not be taken into account.
"DA" - It is the delay time of temperature alarm 1 during a defrost.
Note: Alarm 1 during defrosts and during time "dA" after the end of
defrosts is deactivated, while alarm 2 during defrosts is always
activated.
"1t", "2t" - They are the delay time for the activation of temperature
alarms 1 and 2.
Temperature alarms 1 and 2 are activated when the delay times
expire and after the times "1t" and "2t", when the measured
temperature of the probe set by the alarm rises above or falls below
the respective threshold of maximum and minimum alarm.
