Danfoss AK-RC 204B and AK-RC 205C Temperature Controller Installation Guide

Introduction

This guide provides detailed instructions for the installation, configuration, and operation of the Danfoss AK-RC 204B and AK-RC 205C temperature controllers. These controllers are designed for walk-in coolers and freezers.

Safety Precautions

Important: Always disconnect the power supply before performing any wiring or maintenance. Ensure that all installations comply with local regulations and safety standards. Use only Danfoss-approved probes for correct operation. Avoid spraying the unit directly with high-pressure hoses. The IP65 protection degree is only valid when the protection cover is closed and cables enter the device using appropriate glands.

Installation

Initial Configuration (Assistant Mode)

Upon first power-up, the unit enters ASSISTANT mode, indicated by a flashing 'Ini' message. Follow the on-screen prompts to select the appropriate configuration (Inl option) based on the installation type. The controller offers various Inl options, each corresponding to a specific cold regulation, pump down, defrost, and evaporator fan setup. After selecting the Inl option and pressing SET, the unit will prompt for the desired temperature set point. The assistant mode will then finish, and the unit will begin regulating temperature.

If this is not the first time the wizard is used, a 'dFp' (default parameters) message may appear, allowing the user to choose between resetting only wizard-related parameters or resetting all parameters to factory defaults.

Wiring

Always disconnect the power supply before wiring. Probes and their cables should never be installed in the same conduit as power, control, or supply cables. The power supply circuit must be equipped with a switch of at least 2 A, 230 V, located near the device. Ensure the power supply cable is of the appropriate type (e.g., H05VV-F or NYM 1x16/3) with a cross-section of at least 2.5 mm². Relay and contactor output cables should also have a 2.5 mm² cross-section and be installed with minimal bends. Keep the 120/230 V~ connection area clear of external elements.

Keypad and Indicators

Keypad Functions

ESC: Exits programming menu without saving, returns to previous level, or exits programming.
SET: Scrolls through programming levels or changes parameter values.
SP: Displays probe S2 temperature (if enabled) for 10 seconds, or starts/stops defrost.

Indicators

Various indicators display the controller's status, including Stand-by mode, door open alarms, HACCP alarms, fan status, solenoid status, and compressor status. Temperature is displayed in °F or °C. The 'PRG' indicator shows when the unit is in programming mode.

Configuration Menus

Condensed Programming Menu

Accessed by pressing SET for 3 seconds. Allows quick configuration of frequently used parameters (SP, C1, d0, d1, d4, F3, A1, A2).

Extended Programming Menu

Accessed by pressing SET for 6 seconds. Allows configuration of all unit parameters for advanced installation requirements.

Important: If a password is set (b10=1 or b10=2), the access code will be requested. Certain parameters or menus may not be visible depending on the overall configuration.

Regulation and Control Parameters

The document details numerous parameters for regulation and control, including:

SP: Temperature setting (Set Point).
Calibration (C0, C27): Probe calibration offsets.
Differential (C1): Probe hysteresis.
Set Point Locking (C2, C3): Upper and lower limits for the set point.
Compressor Protection (C4, C5, C6): Delays and states for compressor protection.
Defrost Parameters (d0-d9): Frequency, duration, type, and timing of defrost cycles.
Evaporator Fan Parameters (F0-F4): Fan shutdown temperature, differential, and operation during defrost.
Alarm Parameters (A0-A12): Configuration of temperature alarms, delays, and polarity.
Basic Configuration (b00-b22): Settings for power-up delay, light timing, password function, MODBUS address, and communication speed.
Inputs and Outputs (100-121, 000, 010): Configuration of probes, digital inputs, and relay outputs.
HACCP Alarm (h1, h2): Settings for HACCP temperature and time limits.

Maintenance

Clean the unit surface with a soft cloth, water, and soap. Do not use abrasive detergents, petrol, alcohol, or solvents, as this may damage the unit.

Ordering Information

The document lists the available controller models (AK-RC 204B, AK-RC 205C) and their included accessories, as well as replacement parts such as NTC sensors.

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