Carel uC2SE, User Manual

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60
ENGLISH
μC 2 SE - +030220426 - rel. 2.1 - 09.06.2010
Hc1 to Hc4: compressor operating hour limit exceeded warning
When the number of operating hours for the compressor exceeds the maintenance threshold
(as default equal to zero, and consequently the function is disabled), the maintenance request
signal is activated. The buzzer and the alarm relay are not activated, however the warning relay is
activated (with the expansion card fi tted).
Epr, EPb: EEPROM error
A problem has occurred when saving the parameters to the unit’s non-volatile memory
(EEPROM); in the event of an Epr error, the μC
2
SE continues to perform the control functions with
the data present in the volatile memory (RAM), where there is a physical copy of all of the data.
After the fi rst power failure the confi guration will be lost. The buzzer and the alarm relay are not
activated. If the occurs when starting the unit, “EPb”, the controller will not operate.
ESP: communication error with expansion card
If the controller loses communication with the expansion card, the entire system will be stopped
to avoid adversely aff ecting the unit. The alarm relay is activated and the display will show the
message, with the red LED on steady.
EL1-2: warning, zero crossing error circuit 1-2
If the controller detects errors in the power supply, control may be lost over the fan speed. In this
case, the display will show a warning, and the fans will be controlled at maximum speed. The
alarm is reset automatically, so as to not aff ect the operation of the unit. If the expansion card is
used, the warning relay is activate)
dF1-2: warning, end defrost circuit 1-2 due to maximum time
If the defrost ends after the maximum time when end defrost by temperature or from external
contact has been selected, the unit displays the text dF1 for circuit 1 or dF2 for circuit 2.
The message is cancelled using the delete alarm procedure or when the next correct defrost
cycle is completed. The buzzer and the alarm relay are not activated. If the expansion card is used,
the warning relay is activated (if used).
A1: antifreeze alarm outlet limit circuit 1
The alarm is only detected in water chillers (H01= 2, 3, 4, 5 or 6) by the evaporator water outlet
probe (B2/B6) or, if the electronic expansion driver (EVD) is connected to the tLAN, based on
the evaporation temperature sent by the driver. The evaporator water outlet temperature is
compared against the threshold A01, while the evaporation temperature is compared against the
threshold A14.
The compressors in circuit 1 and the condenser fans in circuit 1 are immediately stopped, the
buzzer and alarm relay are activated, and the display starts fl ashing. If the μC
2
SE is in Standby, the
alarm condition is not detected, and only the heaters are managed. Reset depends on parameter
P5:
1. in the event of automatic reset, the unit restarts automatically if the temperature is above the
value
A01+A02 or A14+A02.
2. in the event of manual reset, the unit can restart manually even if the alarm is active.
After the time A03, if the alarm persists the unit will stop again.
For air/air units the parameter becomes the antifreeze-outlet limit alarm set point. If the outlet
limit is active, the freecooling damper is forced closed and the message SUL is shown on the
display.
A2: antifreeze alarm circuit 2
As for A1 but relating to circuit 2
Ht: high temperature warning
This alarm is activated when the threshold is exceeded (read by B1), set for the parameter P16. It is
delayed at power ON by the parameter P17 and causes the activation of the alarm relay and the
buzzer, without deactivating the outputs. It is reset automatically when conditions that caused the
alarm are no longer present.
Lt: low temperature warning
For direct expansion units (H01=0, 1) the alarm is used to measure a low room temperature using
probe B1 or B2 (depending on par. A06). The alarm may be reset manually or automatically, and
depends on the parameter P05. If the expansion is present, the corresponding relay is activated; in
the event of μC
2 SE module only, the alarm relay will be used.
AHt: high temperature warning when starting the system
The advice does not activate the relay, and displays the message “AHt”.
ALt: low temperature warning when starting the system
The advice does not activate the relay, and displays the message “ALt”.
ELS/EHS: warning, low/high power supply alarm
If the power supply voltage is too low or too high, the corresponding message is displayed.
In these cases, the correct operation of the μC
2 SE is no longer guaranteed. In the low voltage
conditions only the requests to deactivate the loads are eff ected. Any start-up requests remain
pending. The high voltage condition involves the deactivation of all the energised relays.
L: Low load warning
The warning does not activate the relay and displays the message “ L ”; reset is automatic.
tEr: terminal communication error
This alarm is only shown if μC 2 SE has been connected to a terminal. The alarm is generated a fi xed
time (30 s) after μC 2 SE loses contact with the terminal. In this case the unit is disabled for safety
reasons.