Danfoss EKE 400 Installation Guide

Product Identification and Overview

The Danfoss EKE 400 is a controller available in versions with or without a Human-Machine Interface (HMI). A remote HMI, type MMIGRS2, is also supported. The unit is designed for climate control applications and is available with different power supply options: 230 V AC (part numbers 080G5003, 080G5005) or 24 V AC/DC (part numbers 080G5004, 080G5006). The controller features an IP20 rating, operates within a temperature range of -20 to 60 °C (-4 to 140 °F), and supports up to 90% relative humidity (non-condensing).

Connection cables for the EKE 400 and HMI are available in 1.5m (080G0075) and 3.0m (080G0076) lengths.

Principle of Operation

The principle diagram illustrates the system's operation, showing an Evaporator connected to various control valves and sensors. Key components include Control of Hot Gas Valve (CHV), Electronic Expansion Valves (ICLX), Solenoid Valves (ICFE, ICFD, ICFS, ICFW, ICFC, ICFF, ICSH), an Electronic Refrigerant Flow Control (EVRST), a Check Valve (CVP), and an Electronic Shut-off Valve (EVM). The diagram depicts the flow of refrigerant through lines such as the Wet return line, Defrost drain line, Liquid feed line, and Hot gas defrost line, highlighting a 'Soft-opening' function and a 'Drip tray'.

Electrical Connections

The EKE 400 features both lower and upper level connection interfaces for power, communication, and I/O signals.

Lower Level Connection

This level includes connections for Power Supply (LN), Modbus communication (A+, B-), and CANbus. It also provides terminals for Digital Outputs (DO 1-8) and Analogue Outputs (AO 1-4).

Upper Level Connection

The upper level includes connections for Power Supply (L, N), Modbus communication (A+, B-), and CANbus. It also provides terminals for Analogue Inputs (AI 1-4, AI5-AI8) and Digital Inputs (DI 1-8). Connections for external sensors such as the AKS 33 pressure transmitter and Pt1000 temperature sensor are illustrated.

Network Connection (H-R)

When connecting multiple EKE 400 units in a network, the H-R connection must be made between the first and the last local EKE 400 unit. Connections should be made as close as possible to the connector.

Electric Noise Warning

Signal cables for sensors, DI inputs, data communication, and display must be kept separate from high voltage (230 V) electric cables. It is recommended to use separate cable trays and maintain a minimum distance of 10 cm between high voltage and signal cables. For DI input cables longer than 10 meters (33 ft), auxiliary relays placed within 10 meters are recommended to avoid signal degradation.

Technical Specifications

Supply Voltage

The supply voltage depends on the model:

• 85-265 V AC, 50/60 Hz. Maximum power consumption: 20 VA.
• 20-60 V DC and 24 V AC ± 15%, 50/60 Hz. Maximum power consumption: 10 W, 17 VA.

Modbus

Proper installation of the data communication cable is crucial. Refer to separate literature No. RC8AC. Ensure correct bus termination.

Digital Outputs (DO)

8 pcs. DO1 - DO8. Function defined via HMI in the parameter list.

• DO1, DO2: Normally Open contact. Rated for 10 A at 250 V AC for resistive loads, and 3.5 A at 230 V AC for inductive loads.
• DO3, DO4, DO7, DO8: Changeover Contact. Rated for 6 A at 250 V AC for resistive loads, and 4 A at 250 V AC for inductive loads.
• DO5, DO6: Solid state relays. Maximum current (Imax) = 0.5A, Minimum current (Imin) = 50 mA. Leakage current is less than 1.5 mA. Not short-circuit protected. Note: AC only.

Analogue Outputs (AO)

4 pcs. AO1, AO2, AO3, AO4. Function defined via HMI in the parameter list.

• AO1, AO2: 0/10 V DC, 10 mA max for each output.
• AO3, AO4: Opto-insulated. 0/10 V DC, 10 mA max for each output.

External Power Supply: 24 V AC / 24 V DC. Observe: Connect 24 V to N and L (separate supply). Avoid earth fault current. Use a double-insulated transformer; the secondary side must not be earthed. Obtain 0-10 V from terminals N and AO3, respectively N and AO4. Pay attention to the polarity of N.

Analogue Inputs (AI)

4 pcs. AI1 - AI4 and 4 pcs. AI5 - AI8. Function defined via HMI in the parameter list.

Pressure Transmitters

• Ratiometric: 10 – 90% of supply (AKS 32R).
• 1 – 5 V (AKS 32).
• 0-20 mA / 4-20 mA (AKS 33, requires 12 V supply).

Temperature Sensors

• Pt 1000 ohm (AKS 11 or AKS 21).
• NTC 86K ohm @ 25 °C.

Digital Inputs (DI)

8 pcs. DI1 - DI8. The connection can be configured for a shut-down or interruption function.

Valve Configuration

The following table details valve configurations for different line types and their corresponding parameter numbers for Digital Outputs (DO1-DO6).

Dimensions

The EKE 400 unit has the following approximate dimensions:

• Height: 122 mm
• Width: 138 mm
• Depth: 63 mm

The HMI unit also has specific dimensions, with a display area and connection terminals.