Service manual

12-17
CONTROL SYSTEM
SM CINCO 1-A.1 GB
12.5 Run Mode
Run mode is the default operation mode of the system. This is the standard operation mode that is active in field application
(at customer site).
System can go from run mode to other operation modes through keyboard or serial ports.
12.5.1 Mode Setting
12.5.1.1 General Rules
Thermal mode defines the ODU operation mode. There are three possible operation modes:
1. STBY – Standby mode
2. COOL - the unit operate at cooling cycle
3. HEAT - the unit operates at heat pump cycle (deicer will be treated as sub-mode of heat mode in the thermal
Mode setting).
The last mode will be stored in the EEPROM, and it will be restored on system power up, where the default value is
STBY.
12.5.1.2 ODU Mode Definition
The ODU define the system operation mode according these methods (ThermalModeSetting):
1. First request priority (Option 0).
The first IDU which requests different mode than STBY mode will set the new operation mode. The mode will
change once all the units exit the current operation mode.
2. Priority unit (Option 1-5).
If an IDU is defined as a priority unit, the operational mode will be defined according to that unit request, unless
the unit is at STBY mode.
3. SB Input
The ODU will change mode between COOL/HEAT and IDLE according to the SB dry contact input.
12.5.2 Compressor Speed Control
The following diagram describes the sequence of the Target Frequency calculations:
NLOAD calculation
Max/Min freq limitation
NLOAD re-calculation
(Every 1minute)
In Protection (Prot status
other than Normal)?
StepFreq control
Illegal freq checking
Final target freq
Yes
No