Signalling - Johnson Controls York YKN2Open board Technical Information

Probes
Opening or short circuit in the liquid probe, outdoor or indoor
An incident is signalled in the corresponding probe if the value read is lower than ‑33.5 °C
(NTCTPABIERTA), or higher than 93.5 °C (NTCTPCORTO).
If this incident is produced in the liquid probe in heat mode, repeated defrosts are carried out with a
maximum duration of 10 minutes or entry detection of the high-pressure switch signal.
In the case of crossed coils, if an error is detected in the outdoor probe, both fans are started up.
Opening or short circuit in the discharge probe
An incident is signalled in the discharge probe if its value is lower than ‑20 °C (DISTPABIERTA) or higher
than 150 °C (DISTPCORTO).
Opening or short circuit in the accessories probe
An incident is signalled in the discharge probe if its value is lower than ‑33.5 °C (NTCTPABIERTA) or
higher than 93.5 °C (NTCTPCORTO).
Accessories
The accessories can be in three states:
• Connected without being set.
• Connected, set and functional.
• Set but not functional (inhibited).
In this last case an incident is signalled for inhibited accessory, this implies the detection of faults in the
communication, therefore inhibiting the accessory and its outputs are deactivated.

5.2.2 Signalling

Signalling faults is carried out on two levels. One for incidents and another for faults.
Incidents
Incidents do not stop the unit and are indicated by a green LED on the electronic board.
N O T E
If there is no fault, the this LED will flash at a constant frequency.
When an incident is produced, the LED passes through three flashing sequences.
1. The first indicates the affected compressor:
• One flash for stage 1.
• Two flashes for stage 2.
• Three flashes for stage 3.
• Four flashes for others.
2. There is a short pause.
3. The LED indicates the type of incident.
4. There is a short pause.
5. The LED indicates the detected incident.
6. There is a longer pause.
7. The sequence is repeated throughout the duration of the incident.
The incidents are restored when the condition that generates them ceases.
Malfunctions 5
Causes 5.2
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