User manual

40
ENGLISH
ir33 +030220441 - rel. 2.5 - 16.06.10
7.4 Defrost management parameters
Code Parameter Model UOM Type Min Max Def.
d0 Type of defrost -SYF  ag C 0 4 0
dI Interval between defrosts -SYF hours F 0 250 8
dt1 End defrost temperature, evaporator -SYF °C/°F F -50 200 4.0
dt2 End defrost temperature, aux evap. -SYF °C/°F F -50 200 4.0
dt3 End defrost temperature, evap. probe 3 -SYF °C/°F F -50 200 4.0
dP1 Maximum defrost duration, evaporator -SYF min F 1 250 30
dP2 Maximum defrost duration, aux evap. -SYF min F 1 250 30
d3 Defrost start delay -SYF Min C 0 250 0
d4 Enable defrost on start-up -SYF  ag C 0 1 0
d5 Defrost delay on start-up -SYF min C 0 250 0
d6 Display on hold during defrost -SYF - C 0 2 1
dd Dripping time after defrost -SYF min F 0 15 2
d8 Alarm bypass after defrost -SYF hours F 0 15 1
d8d Alarm bypass after door open -SYF h/min C 0 250 0
d9 Defrost priority over compressor protectors -SYF  ag C 0 1 0
d/1 Display of defrost probe 1 MSYF °C/°F F - - -
d/2 Display of defrost probe 2 MSYF °C/°F F - - -
dC Time base for defrost -SYF  ag C 0 1 0
dC1 Time base for alarm delay ’c6’ and ‘d8’ -SYF  ag C 0 1 0
d10 Compressor running time -SYF hours C 0 250 0
d11 Running time temperature threshold -SYF °C/°F C -20 20 1.0
d12 Advanced defrost -SYF - C 0 3 0
dn Nominal defrost duration -SYF - C 1 100 65
dH Proportional factor, variation in dI -SYF - C 0 100 50
Tab. 7.e
Important warning: afor the set times to become immediately operational, the instrument needs to be turned o and on again.
If this operation is not carried out, timing resumes operation the next time it is used.
d0: Type of defrost
For the instruments  tted with defrost relays:
• d0=0 electric heater defrost by temperature;
• d0=1 hot gas defrost by temperature;
• d0=2 electric heater defrost by time, Ed1 and Ed2 not displayed;
• d0=3 hot gas defrost by time, Ed1 and Ed2 not displayed.
• d0=4 eletrical heater temperature defrost by time, Ed1 and Ed2 not displayed.
Defrosts can be performed for all models:
• by temperature, using the defrost probe  tted on the evaporator. In any case, the defrost will be stopped after a maximum set
safety time (dP1 and dP2). The warnings Ed1 and Ed2, “end defrost due to maximum duration” (parameter ‘A8’) can be disabled;
• by time: without the defrost probe;
• by time with temperature control: based on the evaporator temperature, the function is similar to the mode where d0=0. Once
the temperatures dt1 and dt2 have been reached, the controller deactivates the defrost output and then reactivates it if the
related evaporator probes measure a temperature below dt1 and dt2 -1°C. This occurs for the entire duration of the defrost set
using the parameter dP.
Note:
• model S does not have a defrost relay, and consequently the defrost can only be performed by
stopping the compressor and selecting end of defrost by time or temperature. If the alarms Ed1 and Ed2 are not disabled, when
activated, they can be cancelled by pressing PRG and  together for more than 5 seconds. In any case, the signals Ed1 and Ed2
are reset automatically at the start of the next defrost operation.
• if control with two compressor steps is selected (with or without rotation, H1 or H5= 12 or 13) the defrost is performed acting
on both steps.
Default: d0=0 => electric heater defrost by temperature.
dI: Interval between defrosts
The defrosts are performed cyclically at an interval equal to the value of dI in hours (or minutes, see parameter dC), counted from
the end of the previous defrost. The duration of the defrost therefore does not therefore a ect the interval between defrosts. The
interval dI is also maintained when the unit is OFF. If the interval dI expires when the controller is OFF, when it is started again a
defrost is performed.
If dI =0 => the defrost is never performed except when forced from the keypad (manual defrost), from the supervisor or from
the digital input (see parameter A4, A5, A9), or from the Real Time Clock.
Important: PTo ensure regular defrosts, the interval between defrosts must be greater than the maximum defrost duration, plus
the dripping time and post-dripping time.
Note: during the defrost, the temperature alarms are disabled.
Default: dI =8 hours.
dt1: evaporator end defrost temperature set point
This parameter is used to set the end defrost temperature, measured on the evaporator. In any case, the maximum defrost duration is
equal to the value, in minutes, set for parameter dP1.
• if when a defrost is requested, the temperature measured by the defrost probe on the evaporator is greater than the value set for
the end defrost, the cycle is not performed (including the dripping and post-dripping phases). The same is true for the defrost on
start-up, from digital contact, from RTC and from the keypad;
• if the defrost probe on the evaporator is faulty or disabled, the controller performs a timed defrost, with a duration equal to the
value set for parameter dP1;
• if the end defrost set point is not reached within the time set for parameter dP1, the defrost is stopped. If enabled (parameter A8),
the error signal Ed1 is displayed, which persists until the start of the next defrost cycle.
In the defrost by temperature, the parameter establishes the threshold for activating or deactivating the corresponding defrost relay.
Default: dt1=4°C.