This document provides troubleshooting and maintenance information for the Refrigeration Dryer Series RDP 20 - 1900. It also includes details about the RDC 2 controller, its parameters, MODBUS communication, the hot gas bypass valve, and a list of spare parts.
Function Description:
The Refrigeration Dryer Series RDP 20 - 1900 is designed to remove moisture from compressed air, preventing issues such as corrosion and damage to pneumatic equipment. The core function involves cooling the compressed air to a dew point temperature, causing water vapor to condense into liquid, which is then drained. The hot gas bypass valve plays a crucial role in maintaining a stable evaporator temperature, typically between 1-2 °C, to prevent ice formation under varying load conditions. This ensures consistent and efficient drying performance. The RDC 2 controller manages the dryer's operation, including the compressor, fan, and condensate drain, based on sensor readings such as dew point, compressor, and condenser temperatures or pressures.
Important Technical Specifications:
The dryer series covers a range of models from RDP 20 to RDP 1900, with specific spare parts listed for each.
The RDC 2 controller has three 230 V outputs for the compressor, fan, and drain. It also includes an alarm output triggered via an opto triac, capable of handling 600VAC/50mA.
Sensors used for regulation include:
- Tdew (Dew point temperature)
- Tcomp (Compressor temperature)
- Tcond or pcond (Condensation temperature or pressure, 4-20 mA)
The hot gas bypass valve (e.g., TGHE 10, TGHE 20/TGHE 40) has specific torque settings for adjustment (e.g., 3 Nm/2.2 ft-lbf for TGHE 10/20/40, 10 Nm/7ft-lbf for other models).
MODBUS communication is supported, with an address for the MODBUS communication set to 1.
Controller parameters include:
- Drain Cycle Value (default 1)
- Drain Period Value (default 200 sec)
- Min Compressor OFF time (default 1 min)
- CondSensorType (default 0)
- Dew point temperature values are typically displayed in °C, and pressure in Bar.
Usage Features:
The RDC 2 controller provides real-time operational status. At startup, it displays a countdown (COMP TIME X MIN) before the compressor starts. After the countdown, it shows the dew point temperature. Users can view the outlet temperature of the compressor by pressing the UP button and the condensation temperature or pressure by pressing the DOWN button.
The controller indicates the status of regulated components:
- Fan symbol for Fan (ON/OFF)
- Compressor symbol for Compressor (ON/OFF)
- Drain symbol for Drain (ON/OFF)
In normal operation, the compressor runs continuously, the fan is regulated based on condensation temperature/pressure, and the dew point temperature is displayed.
The controller can be turned OFF/ON remotely via an "In. Remote" connection.
Parameters can be adjusted through the controller interface. To change parameters, the SET button must be held for 3 seconds, followed by entering a password (000) and navigating to the desired parameter number.
The hot gas bypass valve can be adjusted to maintain a constant evaporator temperature. This involves unscrewing a cap and turning the valve in a counter-clockwise direction to reduce the temperature on the controller to approximately 1-2 °C. It is recommended to allow 10-20 minutes for the setting to stabilize.
Maintenance Features:
Troubleshooting and maintenance procedures must only be performed by qualified personnel with the necessary knowledge. Before any work, it is crucial to ensure that no part or device is powered, under pressure, or connected to a power source or compressed air system.
The document provides a comprehensive troubleshooting guide for various symptoms:
- No LED lights on controller: Check power source, electrical installation, and circuit board.
- Condensate not drained when TEST button pressed: Check service valve, dryer pressurization, solenoid valve, and circuit board.
- Condensate only drained when TEST button pressed: Clean capacitive sensor.
- Spout blows out air: Clean electromagnetic valve diaphragm.
- Drain in alarm/not working: Check service valve, dryer pressurization, solenoid valve, and controller parameters (parameter "2" to be set to "0").
- Errors "Pf1", "Pf2", "Pf3" (dew point, compressor, condenser sensor errors): Check sensor wiring or replace the controller.
- Error "Lt" (dew point temperature below -2°C): Adjust bypass valve, check ambient temperature.
- Error "Cln" (condenser temperature surpasses 70°C): Check ambient temperature, clean condenser coil, check fan wiring, check temperature sensor connection.
- Error "Ht" (compressor temperature surpasses 110°C): Check copper tubing for leakage (insufficient coolant).
- High dew point temperature (>5°C): Check sensor installation, adjust bypass valve, check for coolant leakage, check ambient temperature.
- Fan on condenser does not work: Check fan electrical wiring, output voltage from controller, and fan operation.
- Dryer does not start: Check electrical installation, controller malfunction, safety switches, phase sequence (for 3-phase dryers), and coolant leakage.
The document notes that when the condensate drain is in alarm, the solenoid valve will open every 7 minutes for 7.5 seconds.
Parameters on the RDC 2 controller can be reset to default values. To do this, hold SET+UP for 3 seconds to enter STANDBY status, then hold UP+DOWN for 3 seconds.
A detailed list of spare parts is provided, categorized by component (e.g., compressor, fan, condenser, filter, sensors, switches, controller, motor protection) and applicable dryer model (RDP 20 - 2600). This facilitates easy identification and ordering of replacement parts.
To Next Page
General