2
User
Guide RS8GD602 © Danfoss 2015-10
Optyma
Plus
TM
Introduction
Application
Condensing unit control
Advantages
• Condensing pressure control in relation to outside temperature
• Fan variable speed regulation
• On/off or variable speed regulation of the compressor
• Heating element control in crankcase
• Day/night controller operation
• Built-in clock function with power reserve
• Built-in Modbus data communication
• Monitoring discharge temperature td
• Oil return management control at variable speed control
Principle
The controller receives a signal for demanded cooling, and it then
starts the compressor.
If the compressor is controlled by variable speed, the suction pres-
sure (converted to temperature) will be controlled according to a
set temperature value.
Condenser pressure regulation is performed again following a
signal from the ambient temperature sensor and the set reference.
The controller will then control the fan, which allows the condens-
ing temperature to be maintained at the desired value.
The controller can also control the heating element in the crank-
case so that oil is kept separate from the refrigerant.
For excess discharge temperature, the liquid injection will be acti-
vated in the suction line.
Functions
• Control of condensing temperature
• Control of fan speed
• On/off control or speed regulation of the compressor
• Control of heating element in crankcase
• Liquid injection into economizer port
• Raising the condenser pressure regulation reference during night
operation
• Both internal and external start/stop cooling
• Safety cut-out activated via signal from automatic safety control
Regulation reference for condensing temperature
The controller controls the condensing temperature in relation
to the ambient temperature. A set point is entered for how much
higher the reference must be. The reference can be raised at night.
Day/Night
The controller has an internal clock function which changes
between daytime and night operation.
During night operation, the reference is raised by the 'Night offset'
value.
This day/night signal can also be activated in two other ways:
• Via an on/off input signal - DI2
• Via data communication.
Reference
Night offset
Night
Day
Day
Set Point
Tamb
