Carel k.Air, User Manual, Page: 63 / 192

63
Functions k.air +030220981 rel. 1.2 - 01.12.2020
30220980_200_R01
TotRegReq
Step 1
Step 2
Step 3
Step 4
Fig. 9.s
Coil with binary steps
This coil uses binary logic to increase the number of control steps by reducing the number of digital outputs. The relationship
between outputs and control steps is as follows:
Cont r ol s tep = 2^digi tal o u tp u t s - 1
Each load connected to the digital outputs must have twice the power as the previous one. The table and image below show
the activation sequence with two outputs and three steps.
R equest D igital output 1 D igital output 2
33% ON OFF
66% OFF ON
100% ON ON
Tab. 9.s
30220980_201_R01
TotRegReq
Step 1
Step 2
Fig. 9.t
Coil with 3-position valve
This confi guration is used to control a 3-position valve using two digital outputs: one to control opening and one to control
closing. The valve travel time can be set for control and to estimate the position.
k.air optimises the opening and closing commands in order to reduce activation of the outputs.
Direct expansion coil with integrated management
This confi guration, available only on k.air mini, involves the installation of a refrigerant circuit using the inputs/outputs, unipolar
expansion valve and communication with the Power+ inverter on the controller, so as to integrate direct expansion architecture
with high effi
ciency. The unit and source heat exchangers are placed respectively in the fresh air intake and exhaust air fl ow.
There is just one circuit with one compressor, which can also be on/off . For BLDC compressors, one of 200 compressor models
can be selected, each pre-mapped with electrical parameters and envelope protection data.
See the chapter “Integrated direct expansion” for more information.