6.4 Dirty filter sensor
The level of air filter clogging in the delivery line is checked by a differential pressure switch that measures the
difference in pressure before and after the filters.
An alarm appearing on the controller display will signal the need to either replace or clean the filters. The unit
continues to operate even when the "filters dirty" message is active.
The cut-in value of the warning message is factory set and can be changed at a later stage by turning the knob of the
differential pressure switch with a graduated scale using a screwdriver.
The table shows the cut-in values set at the factory for the dirty filter differential pressure switch, depending on the
type of filter installed.
Filter type
G4 (EN779:2012) - ISO Coarse 75% (EN ISO 16890)
F5 (EN779:2012) - ePM10 50% (EN ISO 16890)
G4 + F6 (EN779:2012) - ISO Coarse 75% + ePM10
70% (EN ISO 16890)
G4 + F7 (EN779:2012) - ISO Coarse 75% + ePM1 50%
(EN ISO 16890)
G4 + F9 (EN779:2012) - ISO Coarse 75% + ePM1 85%
(EN ISO 16890)
If the filter type is changed after unit installation, we recommend changing the calibration of the dirty
filter differential pressure switch, as shown in the table.
To reduce clogging of the heat exchanger in units supplied with plate heat exchanger, provision has been made for a
filtration stage on the outside air line. The level of outside air filter clogging is not monitored by the dirty filter sensor
installed in the unit.
We recommend performing a check of the outside air filters when the alarm message concerning the
air filters in the delivery line appears.
Filter clogging reduces the air flow rate and, as a result, the unit performance. We recommend that the filters be
cleaned as timely as possible after the alarm message appears.
Translation from original instructions
Packaged Rooftop
50
Pressure switch calibration [Pa]
200
250
250
300
300
We reserve the right to make changes without any prior notice.
UATYA
4P645202-2