Pfannenberg DTI 8361 - User Manual

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Overview

Function Description
Important Technical Specifications
Usage Features
Maintenance Features

This document describes the DTI 8361 side-mounted cooling unit, an industrial cooling solution designed for switch cabinets.

Function Description

The DTI 8361 cooling unit is specifically designed for dissipating heat from switch cabinets with an IP55 protection rating. It operates as a closed-loop cooling system, ensuring that the internal environment of the cabinet remains isolated from external contaminants. The unit is suitable for stationary operation.

The core functionality involves a refrigeration cycle:

Compressor (1): Compresses the refrigerant to high pressure, increasing its temperature.
Condenser (2): Dissipates heat from the high-pressure, high-temperature refrigerant to the ambient air, causing the refrigerant to condense into a liquid. The condenser fan (5) draws in ambient air, passes it through the condenser, and expels it.
Expansion Device (3): Reduces the pressure of the liquid refrigerant.
Evaporator (4): Absorbs heat from the air inside the cabinet, causing the refrigerant to evaporate. This process cools and dehumidifies the cabinet air. The evaporator fan (6) draws air from the cabinet, passes it through the evaporator, and returns the cooled air to the cabinet.
Temperature Sensor (7): Monitors the internal cabinet air temperature, providing data for the electronic control system.

The refrigerant used (R134a) is non-ozone-depleting and non-flammable. Condensate formed during the cooling process is typically evaporated by an optional condensate evaporator. For situations with excessive condensate (e.g., unsealed cabinets or internal temperatures consistently below the dew point), a condensate drain pipe is provided.

Important Technical Specifications

Performance:

Cooling capacity (A35/A35): 3000 / 3200 W
Cooling capacity (A50/A35): 2150 / 2300 W
Refrigerant type: R134a
Refrigerant amount: 1420 g
Thermostat setting (factory set): +33°C (+91.4°F)
Failure indication (enclosure internal temp.): > +45°C (+113°F)
Ambient air temperature range: -40°C to +55°C (-40°F to +131°F)
Enclosure internal temp. range: +18°C to +43°C (+64.4°F to +109.4°F)
Air volume, external circulation: 1200 m³/h
Air volume, internal circulation: 1600 m³/h
Condensation discharge: Condensate discharge pipe
Noise level (1m): ≤ 68 dB(A)
PTC Heater (optional): 1000 W @ 0°C

Electrical Data:

Mains frequency: 50 / 60 Hz
Operating range: DIN IEC 60038
Rated voltage: 230 V
Power consumption (A35/A35): 1250 / 1570 W
Current capacity: 8.5 / 11.7 A
Starting current: 40.0 A

Physical Characteristics:

Dimensions (H x W x D): 1251 x 551 x 225 (mm)
Weight: 66 kg
Installation attitude: Vertical
Unit construction: Standard: Steel
Corrosion protection: Standard: galvanized, electrostatically powder coated (200°C)
Protection system according to EN 60529: IP55 against the enclosure (internal), IP34 against the environment (external)

Usage Features

Control and Monitoring: The unit features an operating display for real-time temperature monitoring and alarm code display in case of malfunction. Parameters can be viewed and set via the display.

Parameter Viewing: Press and hold "Select" for 3s, then press "Select" again to cycle through parameters like internal temperature (ts1, t1), humidity (Hs1), voltage (U), current (SC), communication address (add), and baud rate (bau).
Parameter Setting: After entering the parameter viewing mode, select "PASS" and enter the password "666" to access user-level settings. Parameters like internal temperature setting (t1), cooling stop offset (t3), heater setting (t5), humidity opening point (rH1), and communication address (add) can be adjusted.
Factory Reset: A factory reset option is available by selecting "dEFu" in the parameter setting menu and entering a specific password (contact Pfannenberg service). This clears historical alarms.
Remote Settings: The unit supports Modbus RTU mode, allowing parameters to be set and monitored remotely via PC software.

Safety Features:

Door Contact: A door limit switch can be connected to terminals X54-3,4. When the cabinet door is opened, the cooling unit motors turn off after a time lag, preventing excessive condensate. If no door switch is used, the contacts must be bridged.
Alarm Signals: The unit provides fault signals (X54-1,2 and X51-1,2) that open when a fault occurs, displaying an alarm code on the display.
Power Supply: Requires connection via a disconnecting device with a contact gap of at least 3mm. A fuse (as indicated on the nameplate) must be used for line protection.

Operating Modes:

Start-up Mode: After power-on, the unit enters a start-up mode (approx. 30s) where it shows internal temperature, then starts the internal fan.
Test Mode: Following start-up, a test mode runs for about 120s, sequentially activating external fan, heater, compressor, and then all components.

Maintenance Features

Cleaning: Regular maintenance, ideally monthly, is recommended to ensure optimal efficiency and reliability.

Disconnect power.
Open the casing.
Clean air ducts, condenser, and external fan using a soft brush or compressed air (avoid damaging fins).
Clean the heat exchangers.
Reassemble the casing, ensuring all electrical connections are reconnected.
Reconnect power and observe the power-on self-test.

Troubleshooting: The unit's real-time self-check function diagnoses faults and displays corresponding alarm codes on the operating display. A detailed alarm list (e.g., AL1-AL15) is provided in the manual, covering issues like sensor malfunctions, high/low temperature/humidity, compressor failure, and power supply faults, along with recommended troubleshooting steps.

Spare Parts: A list of spare parts with corresponding Pfannenberg part numbers is provided, including internal/external fans, compressor, capacitors, filter dryer, and controller (main board and display).

Disposal and Recycling: When the unit is no longer needed, it must be disposed of by authorized personnel in accordance with environmental regulations. All components (refrigerants, oils, metals, electronic parts) must be recycled, reused, or discarded responsibly. Contact Pfannenberg service for guidance on disposal.