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  •   -23.97€Isolating safety transformer | 230VAC/24VAC | 40VA | DIN rail | IP30 | Sentera Controls | SATD1-24-40
      -23.97€Isolating safety transformer | 230VAC/24VAC | 40VA | DIN rail | IP30 | Sentera Controls | SATD1-24-40 1

    Isolating safety transformer | 230VAC/24VAC | 40VA | DIN rail | IP30 | Sentera Controls | SATD1-24-40

    Code: SATD1-24-40
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  • Product description

    Isolating safety transformer | 230VAC/24VAC | 40VA | DIN rail | IP30 | Sentera Controls | SATD1-24-40

    The SATD1-24-40 is a Sentera Controls single-phase isolating safety transformer for DIN rail: 230 VAC input, 24 VAC ±5 % output, 40 VA power. It is intended for safely powering 24 VAC automation devices – controllers, transmitters, actuators – in SELV / PELV circuits.

    Key idea:
    When a 24 VAC supply is needed in the control cabinet, this transformer provides it with galvanic isolation from the mains (4 kV) and integrated PTC protection against short circuit and overload – no separate fuse needed on the secondary side.
    Input / output
    230 VAC / 24 VAC ±5 %
    Power
    40 VA
    Installation
    T35 DIN rail, 4 modules
    Protection
    IP30, PTC short-circuit protection

    Operating principle

    The transformer is mounted on a T35 DIN rail and occupies 4 modules; the 230 VAC mains is connected to terminals 1 (L) and 3 (N), the 24 VAC output to terminals 9, 10, cables up to 2.5 mm².

    The primary and secondary windings are galvanically isolated (test voltage 4 kV AC RMS), the element is resin-potted (insulation class B, 130 °C; enclosure class II), and a PTC element in the primary winding protects against short circuit and overload (short-circuit current < 2.0 A).

    Result – 24 VAC ±5 % / 40 VA safety extra-low voltage for SELV and PELV circuits, about 1.7 A output current (calculated as S = U × I), efficiency 79 %. When selecting, add up the power of all connected devices and leave a margin for the actuator start-up current.

    Benefits SATD1-24-40?
    Safe, galvanically isolated low-voltage power for automation with integrated PTC protection – in a compact DIN rail housing.

    Technical specifications

    Product type Single-phase isolating safety transformer for DIN rail
    Manufacturer / code Sentera Controls / SATD1-24-40
    Series SATD1 (12 / 24 VAC; 25 / 40 / 63 VA)
    Supply voltage 230 VAC ±10 %, 50–60 Hz
    Output voltage 24 VAC ±5 %
    Output power 40 VA
    Short-circuit current < 2.0 A
    Efficiency 79 %
    Test voltage (primary–secondary) 4 kV AC RMS
    Protection PTC element in the primary winding (short circuit, overload)
    Insulation class B (130 °C); enclosure class II
    Terminals 1 (L), 3 (N) – 230 VAC; 9, 10 – 24 VAC output
    Cables Up to 2.5 mm²
    Installation T35 DIN rail, 4 modules
    Protection class IP30 (EN 60529), indoor use only
    Operating environment Up to +40 °C, < 90 % rH non-condensing
    Weight 0.88 kg (net)
    Compliance LVD 2014/35/EU, EN 61558-2-6, EN 60529, WEEE 2012/19/EU, RoHS 2011/65/EU

    Manufacturer documentation

    ✔ Recommended by Elektrotechnikos sprendimai

    Original manufacturer documentation – technical data, wiring diagrams and installation instructions.

    Main functions

    • Galvanic isolation – 4 kV isolation between mains and output – for SELV / PELV circuits.
    • PTC protection – against short circuit and overload without a separate fuse.
    • Resin-potted element – durable, resistant to vibration and moisture.
    • Insulation class B, housing class II – 130 °C winding insulation and double protection against electric shock.
    • DIN rail housing, 4 modules – installation in the automation cabinet next to the controllers.
    • Terminals up to 2.5 mm² – convenient for connecting cabinet wires without changing ferrules.
    • Protection against mains disturbances – the loads are isolated from the mains.

    Where is it used?

    • Power supply for 24 VAC controllers, thermostats and transmitters
    • 24 VAC supply for damper and valve actuators
    • Ventilation and heating automation cabinets
    • SELV / PELV control circuits
    • Heat substations (in a cabinet)
    • BMS panels
    • Medium-sized groups of devices up to 40 VA

    On-demand operation

    For damper actuator installers.
    40 VA (about 1.7 A) at 24 VAC – for several damper actuators with a reserve for start-up.
    For HVAC automation integrators.
    Medium 24 VAC power in a 4-module enclosure for an air handling unit cabinet.
    For panel builders.
    A resin-potted element and PTC protection – no separate fuse in the secondary circuit.

    Practical application

    If in a ventilation unit cabinet a 24 VAC controller and three damper actuators together draw about 30 VA, then the SATD1-24-40 (40 VA, about 1.7 A) leaves a reserve for actuator start-up.

    Application guide: how it is used in practice

    The SATD1-24-40 powers 24 VAC automation devices – only the connected load changes:

    Site What is connected Result Installer's note
    Ventilation automation cabinet 24 VAC controller and sensors → terminals 9, 10 All low-voltage devices are powered from a single power supply Add up the power of all devices
    Damper actuators 24 VAC damper actuators Actuators are powered from an isolated safe voltage Leave a margin for the starting moment
    Heating substation 24 VAC valve actuators and controller Safe low voltage near water pipes IP30 – install in a cabinet
    BMS panel 24 VAC device group Galvanically isolated control circuit When 24 VDC is needed – DHDR8-24-36

    How to choose the transformer rating

    Output voltage / load Recommended model
    12 VAC, up to 25 VA SATD1-12-25 (12 VAC, 25 VA)
    12 VAC, up to 40 VA SATD1-12-40 (12 VAC, 40 VA)
    12 VAC, up to 63 VA SATD1-12-63 (12 VAC, 63 VA)
    24 VAC, up to 25 VA SATD1-24-25 (24 VAC, 25 VA)
    24 VAC, up to 40 VA SATD1-24-40 (24 VAC, 40 VA) ← this model
    24 VAC, up to 63 VA SATD1-24-63 (24 VAC, 63 VA)
    Rule: the output voltage must match the supply voltage of the devices (12 or 24 VAC), and the transformer power (VA) must be no less than the sum of the power of all connected devices, with a reserve for actuator start-up.
    When to choose another solution: For 24 VDC supply – DHDR8-24-36 switching power supply (36 W); for powering Modbus devices and boosting the line – DPOM8-24-20.

    Pros

    • 4 kV galvanic isolation
    • Integrated PTC protection
    • Resin-potted element
    • DIN rail mounting, 4 modules
    • Suitable for SELV / PELV circuits
    • Efficiency 79 %

    Cons / limitations

    • Alternating voltage (VAC) output – for 24 VDC devices choose the DHDR8-24-36
    • IP30 – indoors only, in a cabinet
    • Ambient temperature up to +40 °C
    • Power limited to 40 VA – for a higher load choose SATD1-24-63

    Safety and installation notes

    • Installation and connection are to be carried out by a qualified electrician with the 230 VAC supply disconnected.
    • The transformer is intended for indoor use only (IP30), ambient temperature up to +40 °C.
    • Do not exceed the rated power – add up the power of all loads.
    • Ensure air circulation around the transformer in the cabinet.

    Quick selection guide

    230/24 VAC
    40 VA
    DIN rail
    PTC protection
    IP30
    Suitable when you need:
    • to power 24 VAC automation devices;
    • to create a galvanically isolated SELV / PELV circuit;
    • to mount the power supply on a DIN rail.
    Check before use:
    • the supply voltage of the devices (12 or 24 VAC, not VDC);
    • the sum of the power of all loads;
    • the space in the cabinet – the number of modules.
    Important reminder: The SATD1-24-40 output is alternating voltage (24 VAC) – it is not suitable for 24 VDC devices.

    FAQ

    What is the output current?
    The output current is about 1.7 A (40 VA / 24 VAC).
    Is there short-circuit protection?
    Yes, the PTC element in the primary winding protects against short circuit and overload.
    Can 24 VDC devices be powered?
    No, the output is variable, so for 24 VDC devices the DHDR8-24-36 is intended.
    How much space does it take on the DIN rail?
    The transformer occupies 4 modules.
    Can it be installed outdoors?
    No, the protection class is IP30, so it is installed only in a cabinet located indoors.
    What terminals are used?
    The mains is connected to terminals 1 (L) and 3 (N), and the 24 VAC output to terminals 9, 10.

    Isolating safety transformer | 230VAC/24VAC | 40VA | DIN rail | IP30 | Sentera Controls | SATD1-24-40

    Sentera SATD1-24-40 – isolating safety transformer 230/24 VAC, 40 VA, for DIN rail, with PTC short-circuit protection and 4 kV galvanic isolation for SELV / PELV circuits.

    Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.

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