Danfoss Optyma Plus - User Manual

This document serves as a user guide for the Danfoss Optyma Plus™ controller, designed for condensing unit applications. It provides comprehensive information on the controller's functions, operational principles, connections, and troubleshooting.

The Optyma Plus™ controller is engineered to manage condensing unit operations efficiently. Its primary function is to control condensing temperature in relation to the outside ambient temperature, ensuring optimal performance and energy efficiency. The controller receives a signal for cooling demand and initiates compressor operation accordingly. For variable speed compressors, suction pressure (converted to temperature) is regulated to a set temperature value. Condenser pressure regulation is achieved by controlling the fan speed based on ambient temperature and a set reference, maintaining the desired condensing temperature. Additionally, the controller manages a crankcase heating element to prevent oil from mixing with refrigerant and activates liquid injection into the suction line if discharge temperature becomes excessively high.

Usage Features:

The controller offers a range of features to enhance usability and operational flexibility:

Fan Operation: The fan speed can be regulated internally or externally. Internal speed regulation uses terminals 5-6, while external regulation for larger fan motors with insufficient internal outlets connects to terminals 54-55, sending a 0-10V signal. The user can select the control method via menu 'F17'. The fan also has specific behaviors at start-up (Jog Speed) and low loads (FanMinSpeed) to ensure smooth operation and prevent frequent start/stops in low ambient temperatures.
Compressor Control: Compressor operation is initiated by a signal at DI1. To prevent frequent cycling, the controller incorporates minimum ON time, minimum OFF time, and a minimum time between starts. If DI3 is used as a safety stop, the compressor will immediately halt. Variable speed compressors can be controlled via a voltage signal at AO2. An oil-return management feature increases compressor speed for a short period after prolonged low-speed operation.
Temperature Monitoring and Safety: The controller monitors discharge gas temperature (Td) via sensor S3. If Td approaches the set maximum, compressor capacity is reduced. If Td remains high, the fan speed is set to 100%, and if the temperature still doesn't drop after a delay, the compressor is stopped. Liquid injection into the economizer port is activated if discharge temperature nears its maximum allowable limit.
Pressure Monitoring: High pressure monitoring detects condensing pressure exceeding limits, stopping the compressor if the C73 setting is surpassed or if a signal from the interrupted safety circuit (DI3) is received. Low pressure monitoring stops the compressor if suction pressure falls below a set limit, provided the minimum ON time is exceeded. A pump-down limit also stops the compressor if suction pressure drops below a set value.
Crankcase Heating Element Control: The heating element function is active when the compressor is stopped, based on ambient and suction gas temperatures. Power is supplied in a pulse/pause cycle to maintain the desired wattage. The Taux sensor (S5) can be used to monitor crankcase temperature.
Day/Night Operation: An internal clock function allows the controller to switch between daytime and night operation. During night operation, the condensing pressure regulation reference is raised by a 'Night offset' value. This can also be triggered by an on/off input signal (DI2) or data communication.
Digital Inputs: DI1 and DI2 offer contact functions for various purposes, including compressor start/stop, external safety functions, main switch, night setback, and alarm functions. DI3 is a high-voltage input for safety signals from low/high-pressure switches.
Data Communication: The controller features built-in MODBUS data communication. An optional LON RS-485 module can be inserted for alternative communication. Proper cabling is essential for reliable data communication.
Display and User Interface: The controller has a plug for an external display (EKA 163B or EKA 164B) for readings and operation. The display shows either suction pressure (Ts) or condensing pressure (Tc), selectable by the user. LEDs on the front panel indicate relay activation and flash during alarms. Buttons allow navigation through menus, changing settings, and acknowledging alarms.

Maintenance Features:

The Optyma Plus™ controller includes features that aid in maintenance and fault diagnosis:

Fault Message System: In case of an error, LEDs on the front panel flash, and the alarm relay activates. Pressing the top button displays the alarm report. The system differentiates between A-alarms (visible after a time delay) and E-alarms (visible immediately). Common alarms include low suction pressure, no refrigerant selected, DI2 alarm, high/low pressure alarm, standby mode, condenser blocked, max discharge temp, safety alarm, drive alarm, and sensor errors (Pc, Taux, Tamb, Tdis, Tsuc, Ps).
Alarm Destination Settings: The importance of individual alarms can be defined via data communication in the "Alarm destinations" menu, allowing for customized alarm handling and notification.
Controller Software Version Readout: The controller's software version (008) can be read out, which is useful for troubleshooting and ensuring compatibility with system updates.
Operating Status Display: The display can show operating status codes (e.g., SO for normal regulation, S2 for compressor minimum run time, S3 for compressor minimum stop time, S10 for refrigeration stopped by main switch, S25 for manual control, S26 for no refrigerant selected, S34 for safety cut-out) to help diagnose "why is nothing happening" situations.
Factory Settings and Reset: The controller allows saving current settings as new factory settings (067). It can also be reset to original factory settings by cutting power and holding the upper and lower buttons while reconnecting power.
Access Code Protection: An access code (005) can be set to protect controller settings from unauthorized changes.
Operating Time Readouts: The controller provides readouts for the operating time of the condensing unit (P48), compressor (P49), and crankcase heating element (P50), which are valuable for maintenance scheduling and component lifespan tracking.
Alarm Count Readouts: The number of HP alarms (P51), LP alarms (P52), and discharge alarms (P53) can be read out, providing historical data on system faults.
Oil Return Management: This feature tracks compressor speed (P77) and time (P78) to ensure proper oil return. If the counter exceeds a limit, compressor speed is raised to a Boost speed (P79) for a set Boost time (P80) to facilitate oil return, contributing to compressor longevity.