Smoke And High Temperature Detector; Dirty Filter Detector - Johnson Controls York YKN2Open board Technical Information

• If the thermostat is in HVAC mode (cool, heat or auto), there is no kind of demand and the air quality
is correct, the unit is at a standstill.
– If there is air quality demand:
♦ The indoor fan is activated.
♦ The outdoor air economiser damper opens to a maximum of 75%.
♦ The exhaust fan, renewal fan and the wheel motor are activated.
• If the thermostat is in HVAC mode (cool, heat or auto), there is HVAC demand and the air quality is
correct, the energy recovery unit is at a standstill and the heat and cool stages are activated.
– If there is air quality demand:
♦ The exhaust fan, renewal fan and the wheel motor are activated.
♦ The outdoor air economiser damper opens to a maximum of 75%.
• If the thermostat is in cool HVAC mode with an outdoor temperature lower than 20 ºC (economiser
favourable), there is a demand for cold and the air quality is correct, the energy recovery unit is at a
standstill and the outside damper is opened to cool the room.
When the outside damper is opened more than 30%, the exhaust and renewal fan outputs are
activated up to a maximum of 75%, in accordance with the supply temperature.
– If there is air quality demand:
♦ The exhaust fan, renewal fan and the wheel motor are activated.
♦ The outdoor air economiser damper opens to a maximum of 75%.

4.5.8 Smoke and high temperature detector

The smoke detector and high temperature accessories use the same accessory board.
In the case of fitting the two accessories, only one control board must be used and the two closed contacts
for smoke and temperature control must be placed in series in the accessory board input.
When a contact opens, the unit stops and an alarm is triggered. The accessory board output relay closes.

4.5.9 Dirty filter detector

Its function is to indicate whether the filters should be changed.
When entry is detected (closed contact) the output is activated and it is indicated in the thermostat with
communication, until the faults / incidents are reset.
Operation
Switching of the accessories
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4.5
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