Manual terneo sn

Purpose

‍Thermostat terneo sn ‍efficiently manages snow melting systems, ensuring safe movement for people and vehicles during winter without the need for snow removal equipment or salt.

‍The temperature is monitored at the location of the temperature sensor. Based on the sensor's data, the thermostat activates heating when the air temperature falls within the specified range.

Technical data

Rated load current (for category AC-1)

32 А (max 40 A for 10 min)

The limits of regulation

upper: 0...10 °С
lower: –20...–1 °С

Measured temperature range:

–30...+85 °С

Rated power load (for category AC-1)

7 000 VА

Input voltage

230 V ±10%

Weight in the complete set

0,285 kg ±10%

Temperature sensor (in set)

NTC thermo-resistor10 kOhm at 25 °C (R10)

Length of the sensor connected cable

4 m

Supported sensor types:

analog:

NTC 4.7, 6.8, 10, 12, 15, 33, 47 kOhm at 25 °C

digital:

D18

Number combinations under heat, at least

100 000 cycles

Number of combinations  without heating, no less than

1 000 000 cycles

Power consumption

no more than 1,5 kW*h/m

Overall dimensions (w·h·d)

53 × 85 × 66 mm

Installation

‍Read this document carefully before installing and using the thermostat. This will help to avoid possible hazards, errors, and misunderstandings.

‍If thermostat is installed in a humid room, it should be placed in enclosure with a protection degree not lower than IP55 in accordance with GOST 14254. The ambient temperature during installation must be between –5...+45 °C. The installation height of the thermostat should be in the range 0,4...1,7 m above the floor level.

‍The temperature controller should be mounted in a special cabinet, which allows accessible installation and operation. The cabinet must be equipped with a standard 35 mm mounting rail (DIN-rail). The temperature controller has width of three standard 18 mm modules.

The thermostat is mounted and connected after the installation and load testing. In order to protect from short circuits and excess power events appearance in the load circuit, it is necessary to install an automatic circuit breaker (CB), which should  be installed in the live wire break, as shown on Wiring 1.

In order to protect a person from electric shock, a residual current device (RCD) should be installed. The load should be grounded (connected to the protective conductor) for proper operation of the RCD or, if the power supply is two wire, a protective grounding (i.e. load to neutral to the RCD) should be made.

The terminals of the temperature controller are designed for a wire with a cross section not exceeding 16 mm². It is desirable to use a soft copper wire to reduce the mechanical loads on the terminals. The use of aluminum is not desirable. Strip the ends of wires 10 ± 0,5 mm. If the stripped end is longer, it may cause a short circuit and, if shorter, can cause an unreliable connection. Use cable lugs. Loosen the terminal screws and insert the stripped end of the wire into the terminal. Tighten the power terminal with moment of 2,4 N·m and sensor terminal — 0,5 N·m. Poor tightening can lead to poor contact and overheating of terminals and wires, and excessive tightening — to damage of terminals and wires. The wires are tightened in the power terminals with a screwdriver with a bit width of not more than 6 mm, and in the terminals for the sensor — of not more than 3 mm. A screwdriver with a bit width of more than 6 mm for power terminals (more than 3 mm for sensor terminals) can cause mechanical damage to the terminals. This may cause to the loss of the warranty.

It is necessary for the temperature controller to switch the current to no more than 2/3 of the maximum current specified in the specification. If the current exceeds this value, the load must be connected through a contactor (magnetic actuator, power relay), which is optimized for this current (Wiring 2).

‍Air temperature sensor installation ‍
Air temperature sensor should be mounted on the wall  or under the edge of the roof in order to ensure its protection from direct sunlight, rain and snow, and ensure the opportunity for easy replacement in the event of a malfunction or damage (Figure 1). If necessary, it is allowed to shorten and expand sensor connecting wires (separate cable not more than 20 m long with a cross-section greater than 0,75 mm²). Power wires should not be placed near connection wire of sensor otherwise they may cause interference.

Figure 1. Air temperature sensor installation

Electrical connection diagram

‍The thermostat supports two types of sensors: analog (R10) and digital (D18). The analog sensor is supplied with the thermostat and is connected to terminals 1 and 2.

‍To connect a digital sensor, connect the blue wire to terminal 2 and the white wire to terminal 1, and be sure to change the Sensor type to d18 in the menu.

‍The supply voltage (230 V ±10%, 50 Hz) is supplied to terminals 3 and 4, and the phase (L) is determined by the indicator and is connected to terminal 4, and a neutral (N) — to the terminal 3.

‍The load wires are connected to terminal 5 and a neutral terminal block (not included in the set).

Diagram 1.  Connection diagram of  the thermostat, circuit breaker and RCD

Diagram 2.  Connection through  a contactor (magnetic starter)

Settings using buttons

Use "≡" to navigate the menu, and "+" or "–" to adjust  parameters. The first button press makes the parameter blink, while the second press changes its value.  If no buttons are pressed for 5 seconds, the display will revert to showing the temperature.