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  • New item   Modular photo relay | twilight switch with external sensor | 16 A | 110–240 V AC | 1–10,000 lx | 1NO | IP65 sensor | DIN | VEXEN | TWR923

    Modular photo relay | twilight switch with external sensor | 16 A | 110–240 V AC | 1–10,000 lx | 1NO | IP65 sensor | DIN | VEXEN | TWR923

    Code: TWR923
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    Price 65.88 € VAT incl.
    ( 54.45 € VAT excl. )
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    DIN rail twilight switch with external sensor: 1–1000 / 10–10,000 lx, 16 A AC1, OFF/×1/×10/ON, 1 module.

  • Product description

    Modular photo relay with external sensor | 16 A | 1–10,000 lx | VEXEN TWR923

    VEXEN TWR923 is a twilight switch with two sensitivity ranges: 1–1000 lx and 10–10,000 lx. The relay is mounted in the panel on a DIN rail (1 module), while light is measured by an external sensor installed outdoors. The lower range is for ordinary outdoor lighting, the higher one for equipment that must be controlled by daylight.

    Key point:
    One relay covers both dusk and bright daylight. You do not have to pick a separate model for each site: the same TWR923 can be used for street lighting, shop windows or equipment that must switch on when the day turns overcast.
    Sensitivity
    1–1000 / 10–10,000 lx
    Output
    1NO, 16 A AC1
    Supply
    110–240 V AC, 50/60 Hz
    Mounting
    1 module, DIN rail
    Operating temperature
    −35…+75 °C

    Operating principle

    The external sensor continuously measures ambient illuminance. When light falls below the set threshold, the relay closes the output contact; when light rises above the threshold plus hysteresis, the contact opens.

    The threshold is set with the “Lx” knob on a 1–1000 lx scale. The “Func” mode switch has OFF / ×1 / ×10 / ON positions: in ×1 the 1–1000 lx range applies, in ×10 the scale value is multiplied by 10 (10–10,000 lx).

    A switching delay of about 2 min prevents the relay from chattering because of car headlights or a passing cloud. The ON and OFF positions switch lighting on permanently or off. A green LED indicates supply, a red LED indicates an active output.

    Why two ranges?
    Street and yard lighting is usually switched on at 5–20 lx, shop windows and signage at 30–80 lx; the ×1 position is enough for that. An overcast day is already thousands of lux, so for daylight-based control (e.g. supplementary indoor lighting or ventilation) the ×10 position is used.

    Technical specifications

    Product type Modular twilight switch (photo relay) with external sensor
    Manufacturer / model VEXEN TWR923 (RELEVA series)
    Supply voltage 110–240 V AC, 50/60 Hz (−15 % / +10 %)
    Output 1 × SPST (1NO)
    Switching current 16 A (AC1)
    Switching voltage 250 V AC / 24 V DC
    Min. breaking capacity DC 500 mW
    Light sensitivity range 1–1000 lx (×1) and 10–10,000 lx (×10)
    Modes OFF / ×1 / ×10 / ON
    Switching delay approx. 2 min, with hysteresis
    Sensor tolerance ±35 %
    Indication green LED – supply, red LED – output
    Power consumption up to 2 VA
    Terminals 1 × 2.5 mm² or 2 × 1.5 mm²
    Protection rating IP40 front panel, IP20 terminals
    External sensor protection rating IP65 – the sensor is installed outdoors
    Dimensions / weight 90 × 18 × 64 mm, 1 module / 65 g
    Mounting DIN rail (EN/IEC 60715), any position
    Operating and storage temperature −35…+75 °C
    Overvoltage category / pollution degree III / 2
    Standard EN 60255-1

    Main functions

    • Two sensitivity ranges – 1–1000 lx for dusk and 10–10,000 lx for daylight.
    • Automatic switch-on at dusk – lighting is on only when needed.
    • Protection against false triggering – hysteresis and a delay of about 2 min ignore short light changes.
    • ON / OFF positions – lighting can be switched on or off without disconnecting the automation.
    • Wide operating temperature range – −35…+75 °C, suitable for unheated outdoor panels.
    • Compact housing – only 18 mm wide, fits a small panel.

    How does it differ from similar models?

    • VEXEN TWR1 – Same series, but a single 1–100 lx range – easier to set a low threshold precisely at dusk.
    • VEXEN VSOU-1 – 1–50,000 lx – an even wider range, when the threshold may be in bright daylight.
    • VEXEN DTWR972 – Digital relay with timer: lighting can be switched off, e.g. after midnight, and on again before dawn.
    • Eti SOU-1 – Eti photo relay with a 1–50,000 lx range and 16 A output – an alternative from another manufacturer.

    Where is it used?

    • Street and driveway lighting
    • Yard, path and car park luminaires
    • Facade, shop window and sign lighting
    • Switching on supplementary lighting when the day turns overcast
    • Floodlights at warehouses, farms and industrial sites
    • Unheated outdoor panels and lighting cabinets
    • Replacing timers and manual switches in existing panels

    Use by need

    For the electrician.
    One model for different sites: ×1 for dusk, ×10 for daylight, mounting in 1 module.
    For the home or farmstead owner.
    The yard is lit every evening without adjusting a timer, and luminaires are not wasted during the day.
    For the company or shop manager.
    Shop window, sign and site lighting follows real light – lower costs and less manual work.

    Practical use

    If a shop sign must switch on not only in the evening but also on a dark winter day, TWR923 handles it. Mount the relay in the panel and the sensor on the north wall where the sign itself does not light it. Set the switch to ×10 and the knob to about 100 (i.e. about 1000 lx), and the sign switches on when the day turns overcast. If only evening switching is needed, return the switch to ×1 and set about 20–50 lx.

    Pros

    • Two ranges: 1–1000 lx and 10–10,000 lx
    • 16 A AC1 output contact
    • OFF / ×1 / ×10 / ON modes
    • Hysteresis and a delay of about 2 min
    • Operating temperature −35…+75 °C
    • Only 1 DIN module, supply 110–240 V AC

    Cons / limitations

    • 16 A is rated for AC1 (resistive) load – for LED drivers and floodlights with high inrush current use a modular contactor
    • A threshold of a few lux is harder to set precisely than on a 1–100 lx relay – VEXEN TWR1 is more convenient for that
    • No timer for night-time switch-off – VEXEN DTWR972 offers this function

    ⚠ Safety and installation notes

    • Mount the sensor where daylight reaches it but the controlled luminaires do not – otherwise the relay will start switching itself off.
    • Do not point the sensor south into direct sun or towards the road where car headlights hit it.
    • The relay housing is intended for a panel (IP40 / IP20) – only the sensor is installed outdoors.
    • For LED luminaire groups with high inrush current the relay must control a modular contactor coil, not the luminaires directly.
    • Protect the circuit with a suitable circuit breaker and use wire no larger than 2.5 mm² in the terminals.
    • Installation must be carried out by a qualified electrician after disconnecting and verifying the absence of voltage.

    Quick selection guide

    1–10,000 lx
    16 A AC1
    110–240 V AC
    1 DIN module
    Suitable when you need to:
    • switch outdoor lighting on automatically at dusk;
    • control lighting or equipment by daylight;
    • use the relay in an unheated outdoor panel in the cold season.
    Check before use:
    • load type and inrush current (LED – via a contactor);
    • where the sensor will be mounted and how its cable will be routed;
    • which range (×1 or ×10) you will use.
    Important reminder: a photo relay controls lighting by light level, but it does not replace protective devices and does not switch lighting off in the middle of the night – that requires a relay with a timer.
    ☝ Elsprendimai.eu recommends:

    FAQ

    How do I choose the range?
    For ordinary evening lighting – ×1 (1–1000 lx), for daylight-based control – ×10 (10–10,000 lx).
    What threshold should I set for yard lighting?
    Usually 5–20 lx in the ×1 position is enough; for shop windows and signage 30–80 lx.
    Where should the sensor be mounted?
    Outdoors, on the north side of the building, where daylight reaches it but not the controlled luminaires or car headlights.
    Can LED floodlights be connected directly?
    A small load – yes, but for larger LED groups use a modular contactor because of inrush current.
    Why does the lighting not switch on immediately?
    The relay has a delay of about 2 min – this protects against false triggering.
    Can the relay be installed outdoors?
    No, the relay is mounted in a panel on a DIN rail; only the sensor is installed outdoors.

    Modular photo relay with external sensor | 1–10,000 lx | 16 A | VEXEN TWR923

    VEXEN TWR923 is a modular twilight switch with an external sensor, two sensitivity ranges (1–1000 lx and 10–10,000 lx), a 16 A AC1 output and OFF/×1/×10/ON modes. Suitable for outdoor lighting and daylight-based control.

    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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