Control System - Electra DELTA 22 Service Manual

11.

CONTROL SYSTEM

11.1 General Functions and Operating Rules (for single split
models)
The DCI software is fully parametric.
All the model dependent parameters are shown in Blue color and with Italic style
[parameter].
The parameters values are given in the last section of this control logic chapter of the
service manual.
11.2 System Operation Concept
The control function is divided between indoor and outdoor unit controllers. Indoor unit is the
system 'Master', requesting the outdoor unit for cooling/heating capacity supply. The outdoor
unit is the system 'Slave' and it must supply the required capacity unless it enters into a
protection mode avoiding it from supplying the requested capacity.
The capacity request is transferred via indoor to outdoor communication, and is represented
by a parameter called 'NLOAD'. NLOAD is an integer number with values between 0 and
127, and it represents the heat or cool load felt by the indoor unit.
11.3 Compressor Frequency Control
11.3.1 NLOAD setting
The NLOAD setting is done by the indoor unit controller, based on a PI control scheme.
The actual NLOAD to be sent to the outdoor unit controller is based on the preliminary
LOAD calculation, the indoor fan speed, and the power shedding function.
Indoor Fan Speed Maximum NLOAD Cooling
Low
Medium
High
Turbo
Auto
Mode
Cool
Heat
SM DUO38 1-E.1 GB
NLOAD limits as a function of indoor fan speed:
Max NLOADIF1C
Max NLOADIF2C
Max NLOADIF3C
Max NLOADIF4C
Max NLOADIF5C
NLOAD limits as a function of power shedding:
Power Shedding OFF
No limit
No limit
CONTENT
CONTROL SYSTEM
Maximum NLOAD Heating
127
127
127
127
127
Power Shedding ON
Nominal Cooling
Nominal Heating
11-1