Temperature controller Voltcraft ETC-902, NTC/PTC input, -30 to 50°C range, relay output 10 A

Voltcraft ETC-902 is a compact temperature controller designed for simple thermostatic regulation in small HVAC, refrigeration, incubation and laboratory setups. It accepts either NTC or PTC sensor inputs and monitors temperature in the range from -30 to 50°C. The controller provides a single relay output rated at 10 A for direct control of heaters, coolers or other switching devices. Its straightforward interface and robust relay output make it suitable where stable temperature control and a basic on/off control method are required.

Advantages

The device supports both NTC and PTC sensor types, enabling flexible sensor selection to match existing probes or application requirements. With a measuring range of -30 to 50°C it covers common refrigeration, incubation and environmental control needs. The integrated relay output is rated for 10 A, allowing direct switching of many small heating and cooling loads without additional contactors. Compact housing and a simple control concept reduce installation complexity and make the unit easy to integrate into confined setups.

Suitable for

• Small refrigeration systems and cold cabinets
• Incubators and hatching equipment
• Basic laboratory temperature control
• Heating or cooling control in small HVAC or process applications
• DIY environmental chambers and prototypes

Key specifications

• Sensor input: NTC and PTC compatible
• Temperature measurement range: -30 to 50°C
• Control output: relay, single pole, rated for 10 A
• Control type: on/off thermostatic control via relay switching
• Typical applications: heating and cooling device switching, environmental regulation

How to use

Mount the temperature controller in a protected location where the display and controls are accessible while keeping the sensor probe positioned at the representative point for the measured environment. Connect the chosen NTC or PTC sensor to the appropriate input terminals following the manufacturer's wiring arrangement. Wire the heating or cooling device to the relay output, respecting the 10 A current limit and local electrical safety regulations. Configure setpoint and hysteresis (if available) according to the required temperature stability to avoid frequent switching. Perform an initial test cycle to verify correct sensor operation and switching behavior before continuous use.

Usage recommendations

Use sensors of appropriate type (NTC or PTC) and rating for the intended environment; avoid placing the probe near direct heat sources or drafts. Ensure the switched load does not exceed the relay's 10 A rating and add an external contactor or relay if higher currents or inductive loads must be controlled. For precise control or faster response, pair the controller with a properly sized sensor and allow sufficient settling time after setpoint adjustments.