Regin TTC25 Triac Controller for Proportional Electric Heating

Product Overview

The TTC25 is a proportional, 3-phase electric heating controller with automatic voltage adaptation. It operates through stepless, time-proportional control, adjusting the on-time and off-time based on the current heat demand. It is primarily intended for use with Regin's NTC series of sensors for supply air or room temperature control. The TTC25 can control both symmetrical Y-connected and symmetrical or asymmetrical Delta-connected 3-phase heaters. It is designed for DIN-rail mounting.

Technical Data

• Supply Voltage: 3-phase, 210...255 V AC or 380...415 V AC, 50...60 Hz with automatic voltage adaptation.
• Max. Current: 25 A/phase.
• Max. Load: 3300 W/phase at 230 V (25 A), 5750 W/phase at 400 V (25 A).
• Min. Load: 530 W/phase at 230 V (4 A), 920 W/phase at 400 V (4 A).
• Protection Class: IP20
• Ambient Temperature: 0...40°C, non-condensing.

Installation

Mount the TTC25 on a DIN-rail in a cabinet or other casing. Mount the controller vertically with the text right side up. Note: At full power, the TTC25 emits approximately 45 W of excess heat, which must be properly dissipated.

Wiring

Connect the supply voltage to terminals L1in, L2in, and L3in. The load should be connected to terminals L1out, L2out, and L3out. The controller must be grounded and the supply voltage must be interlocked via a high temperature limit switch.

Main sensor and external setpoint: Use terminals 1 and 4 (polarity insensitive). Terminals 2 and 3 are internally connected and used to simplify wiring with an external setpoint potentiometer. Switch 1 is used to select internal or external setpoint.

Limitation sensor: Use terminals 5 and 6 (polarity insensitive). Used for minimum or maximum limitation of supply air temperature during room temperature control. Switches 2 and 3 are used to set the desired function (Min/Max limitation active/deactivated). Min and Max potentiometers set the desired limitation temperatures.

External control signal: The TTC25 can be used with an external 0...10 V DC control signal. Remove the wire strap between terminals 7 and 9 and connect the control signal.

Settings

Potentiometers:

• Setp.: Setpoint 0...30°C.
• Min: Minimum supply air temperature limit for room control with minimum limitation (0...30°C).
• Max: Maximum supply air temperature limit for room control with maximum limitation (20...60°C).
• CT: Pulse period (6...60 seconds).

Switches:

• Switch 1: Down = External setpoint potentiometer; Up = Internal setpoint potentiometer.
• Switch 2: Up = Minimum limitation active; Down = Minimum limitation deactivated.
• Switch 3: Up = Maximum limitation active; Down = Maximum limitation deactivated.

Note: The minimum and maximum limitation functions can be used separately or simultaneously.

Control Principle

The TTC25 pulses the entire load On-Off. The controller adjusts the mean power output to the current power demand by proportionally adjusting the On-time and Off-time ratio. The pulse period is settable via the CT potentiometer.

The TTC25 uses zero phase-angle firing to eliminate radio frequency interference. It automatically adapts its control mode to the dynamics of the controlled object. For rapid temperature changes (e.g., supply air control), it acts as a PI controller. For slow temperature changes (e.g., room control), it acts as a P controller.

Start-up and Fault Finding

1. Ensure all wiring is performed correctly.
2. Measure the resistance between output terminals (L1out-L2out, L1out-L3out, L2out-L3out).
3. Turn on the supply voltage and set the setpoint knob to maximum. The LED should be continuously on or pulse with increasing on-time.
4. Turn the setpoint knob to minimum. The LED should be off or pulse with decreasing on-time. In a middle position (setpoint = actual value), the LED pulsing should coincide with the controller pulsing current to the heater.

Troubleshooting tips:

• Disconnect external sensors and potentiometers and measure their resistance individually.
• With sensor terminals disconnected and all switches down, the controller should provide full output and the LED should be lit.
• If the LED is off and no current flows, check supply voltage. If voltage is present, the controller may be faulty.
• If the LED is lit but no current flows, check heater resistance. If resistance is OK, the controller may be faulty.
• Short-circuit sensor inputs 1 and 4. The controller should provide no output and the LED should be off.
• If the LED is off but current flows, the controller may be faulty. If the LED is lit, recheck the short-circuiting.
• If all checks pass, reconnect sensors and potentiometers as per the wiring diagrams.

Compliance

This product conforms to the European Low Voltage Directive (LVD) 2014/35/EU and the EMC Directive 2014/30/EU, as well as RoHS Directive 2011/65/EU.