Coreco OPd Error Code
Carel RTN400 controller — Door-open alarm
Source: Coreco_rtn400_instruction_sheet_9is24288-1_rel0413_en_termostatos.pdf
What does Coreco OPd mean?
On the Coreco controller (Carel RTN400), OPd is door-open alarm: digital input activated (door open for a time greater than tdO); label Opd recorded in folder ALr, alarm icon permanently on; regulation blocked as requested by dOd.
Symptoms
- Display/record shows OPd
- Alarm icon permanently on
- Rising cabinet temperature while the door is open
Common causes
- Door open longer than the tdO delay
- Door not closing / misaligned seal
- Door switch or wiring fault
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Diagnostic steps
Close the door
OPd is the door-open alarm; shut the door and confirm it clears.
Check the door switch
Verify the door closes and the switch reports closed when shut.
When to call a professional
If the door is closed but the alarm persists, have a qualified technician test the door switch/wiring.
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Other Coreco Error Codes
Control probe (probe 1) error — signal interrupted, short-circuited or incompatible probe
Evaporator / defrost probe (probe 2) error — signal interrupted, short-circuited or incompatible probe
Condenser / product probe (probe 3) error — signal interrupted, short-circuited or incompatible probe
Immediate or delayed alarm from the multifunction digital input (external alarm)
Open-door alarm from the door-switch digital input
Low-temperature alarm — measured temperature below set point by more than parameter AL
High-temperature alarm — measured temperature above set point by more than parameter AH
Unit parameter reading (data) error — saved configuration data error
Operating parameter reading (data) error — manual reset
Defrost ended by timeout — last defrost stopped on maximum duration, not on temperature
Defrost running — status message shown during a defrost cycle (not an alarm)
Dirty-condenser warning/alarm — pre-alarm (cht) between Ac-AE and Ac, then alarm (CHt) when Ac is exceeded and refrigeration stops (manual reset)
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