Bohn PRO3 Installation And Operation Manual page 18

TROUBLESHOOTING
The following table shows a number of situations that may occur on the various models.
The most frequent causes and corresponding checks are described:
Problem
the compressor does not start
(signaled by the compressor LED flashing)
the temperature is over the set limits but there
is no alarm message and the buzzer, if fitted,
does not sound
alarm IA is signaled (multifunction input)
without actually being active
the alarm connected to the multifunction
input is not detected
the defrost is not activated
the manual defrost is not activated and the
defrost LED flashes
the high temperature alarm is shown
after a defrost
the display remains frozen even
after the defrost
after modifying a parameter the controller
continues working with the old values
the evaporator fan does not start 1
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P R O T O P M O U N T P A C K A G E D R E F R I G E R A T I O N S Y S T E M
3
Cause
• compressor delay set defrost post
• dripping in progress
alarm delay set
the multifunction input generates an
alarm when the contact opens
alarm delay set or parameter
programming error
defrost duration too short (dP)
interval between defrosts dI=0:
in this case the defrost is not activated
the end defrost temperature is too low or
the evaporator temperature is too high
compressor protection times set
the alarm delay after defrost is too
short or the alarm threshold is too low
the ambient temperature has not yet
reached the set point or alternatively
the time d8 has not elapsed
the instrument has not updated the old
value or alternatively the parameter setting
procedure has not been ended correctly
by pressing the SET button for 3 s
1. a compressor and fan start delay has
been set
2. if F0=1 (fan managed by fan controller)
• the evaporator is "hot": the evaporator
temperature can be read by selecting
parameter /d
• dripping in progress
• F1 (evaporator fan control set point)
too low
• post-dripping delay set
3. if F0=0
• F2=1 and the compressor is off
• dripping in progress
• post-dripping in progress
Checks
parameters c0, c1 and c2 and dd
parameters Ad, c6, d8
connection of the input and whether
this is closed in normal operation
1. if A4=1
2. the status of digital input A7
parameters dP and dI
parameters dt and d/ (defrost probe)
parameter d9 (select d9=1)
parameters d8 and AH
wait or reduce d8
turn the instrument off and on again
or alternatively reprogram the
parameters correctly
1. parameter c0
2. parameters F0, F1, Fd, dd and d/
3. parameters F0, F2, dd and Fd