The Hugo Muller 923500 is an analog twilight switch 230V that turns lighting on at dusk and off again at dawn without anyone touching a switch. A light sensor reads the ambient level outside, and when it drops past the level you set, the relay in the din rail module closes.

Setting it is done with a dial, not a menu. The adjustable range covers 1 to 100 Lux on one scale and 50 to 1,000 Lux on the other, so the same unit suits a dim car park entrance or a bright forecourt. Built in time delays of roughly 8 seconds on and 40 seconds off stop passing headlights or a cloud from flicking the lights on and off.

This version, 923500, comes with the sensor for wall mounting, rated IP54 for outdoor use. The 16A switching capacity with zero cross switching and AgSnO2 contacts handles large lighting loads directly, including 3,000 W of filament or halogen lamps and 3,600 W of uncompensated fluorescent. The module is a narrow 17.5mm wide and clips onto standard 35mm din rail, so it takes one module space in the board.

Key Features

Automatic dusk to dawn lighting control with no manual switching
Adjustable switch on level from 1 to 100 or 50 to 1,000 Lux
Built in time delays prevent false triggering from passing light
16A switching capacity handles large lighting loads directly
Zero cross switching extends relay life
Narrow 17.5mm module takes one space on 35mm din rail
IP54 wall mounting sensor supplied for outdoor placement
Genuine Hugo Muller product manufactured in Germany

Technical Data

Supply voltages	230 V, 50 Hz
Power consumption (real power)	0,5 W
Channel	Normally open
Switching capacity resistive load: inductive load:	16 A / 250 V~ at cosϕ=1 4 A at cosϕ=0,6
Zero-cross switching	Yes / for relay-saving switching
Contact material	AgSnO2
Filament Lamp Halogen Lamp	3.000 W
Fluorescent Lamp uncompensated	3.600 W
Fluorescent Lamp parallel compensated (130 µF)	1.300 W
Compact Fluorescent Lamp	18 x 7 W 12 x 11 W 10 x 15 W 10 x 20 W 10 x 23 W max.
Switching-On value	1–100 / 50–1.000 Lux
Time delay	approx. 8 sec. at ON, approx. 40 sec. at OFF
Switch-off	approx. 1.3 times the value of switching ON
Mounting	35 mm DIN-rail
Permitted ambient temperature	Sensor unit –35°…+50°C Control unit –10°…+40°C
Type of protection	IP 54 for sensor 923500 IP 65 for sensor 923501 IP 20 for control unit
Sensor wiring, cross section	min. 0,5 mm2

Product details

Analogue twilight switch
DIN-rail mounting 17.5mm
Switching Capacity 16A
923500 – Sensor for Wall Mounting
Make / Brand: Hugo Muller
Country of Origin: Germany
SKU: 923500

Download Product Manual

Common Applications

Street and car park lighting, building facade and signage illumination, warehouse yard and loading bay lights, villa and compound external lighting, security lighting on gates and perimeters, and any installation where lights should follow daylight rather than a fixed time.

923500 or 923501

Both units are identical apart from the sensor. The 923500 supplied here has the IP54 sensor for wall mounting, which suits an external wall, soffit or pole where it reads open daylight. If the sensor needs to sit inside a housing or enclosure instead, order the 923501 analog twilight switch with panel sensor, which carries an IP65 sensor for mounting within a housing.

For other switching based on time rather than daylight, see the full digital and analog twilight switches range, or browse digital and analog timers for time clocks and staircase timers that can run alongside this unit on the same rail.

Why Buy From Qahraba

Qahraba supplies electrical contractors, panel builders and procurement engineers across the UAE and worldwide. Local UAE orders ship within 1 to 2 working days, or collect free from our Dubai store. Call or WhatsApp +971 52 913 9543 for bulk pricing or technical help.

FAQ,s

What does an analog twilight switch do?

It switches lighting on when natural light falls below a set level and off again when daylight returns. A sensor measures the ambient light and the din rail module does the switching, so the lights follow actual daylight instead of a clock.

What is the difference between 923500 and 923501?

Only the sensor. The 923500 has an IP54 sensor for wall mounting, while the 923501 has an IP65 sensor made to be mounted within a housing. The control module and all electrical data are the same.

How is the switch on level set?

By dial, across two ranges: 1 to 100 Lux and 50 to 1,000 Lux. The switch off point sits at roughly 1.3 times the switch on value, which creates a gap so the lights do not hunt at dusk.

Why does it have a time delay?

To ignore short light changes. Around 8 seconds on and 40 seconds off means a passing vehicle, a cloud or a reflection will not trigger the relay.

What load can it switch?

16A at 250V on resistive load, including 3,000 W of filament or halogen lamps and 3,600 W of uncompensated fluorescent. Check the full table for compact fluorescent and compensated figures.

How much rail space does it need?

17.5mm, which is one standard module on 35mm din rail.

Can the sensor be mounted outdoors?

Yes. The 923500 sensor is IP54 rated for wall mounting outdoors, though the control module itself is IP20 and must stay inside the board.

Analog Twilight Switch 230V Din Rail 923500 Hugo Muller