Shelly 1 Gen3 can make ordinary switches smart without replacing them
A smart home does not necessarily require replacing every light switch, gate controller or appliance with something new.
The Shelly 1 Gen3 takes a different approach.
This small Wi-Fi relay sits behind or alongside existing electrical equipment and adds remote switching, automation, schedules and smart-home integration to a circuit that may originally have had no connected features at all.
That basic idea is what makes Shelly products interesting.
Instead of making the visible switch itself the smart device, Shelly can put much of the intelligence behind the scenes.
The Shelly 1 Gen3 then adds newer capabilities including Matter support, an upgraded processor, 8MB of flash memory, scripting and local-network control.
For South African users, it has another important advantage: Shelly has an official local presence, with Nology identified as the official South African distributor.
Shelly 1 Gen3 is a compact smart relay
The Shelly 1 Gen3 measures approximately 37 × 42 × 16mm and weighs only 26g.
That compact form allows it to fit into many electrical enclosures and switch installations where space is limited.
The device contains one relay output and one switch/button input.
A conventional wall switch can therefore remain part of the system rather than becoming redundant simply because smart control has been added.
That matters in a family home.
People should not need to find a phone every time they want to turn on a light.
A properly configured Shelly installation can preserve conventional manual switching while also adding app control, schedules and automation.
View the official Shelly 1 Gen3 product page
IMAGE 1 — INSERT HERE
Alt text: Shelly 1 Gen3 smart relay
Caption: The Shelly 1 Gen3 is a compact Wi-Fi relay designed for retrofit smart-home installations.
Shelly 1 Gen3 uses dry contacts
One of the most important features is the potential-free, or dry-contact, relay.
A dry contact is electrically isolated from the power supply used to operate the Shelly itself.
That gives an installer more flexibility than a relay whose switched output is permanently tied to the same supply voltage powering the smart module.
For example, the Shelly may be powered from one suitable supply while its relay contacts act as a switch for a separate compatible control circuit.
This is particularly useful for equipment such as gate motors, garage-door controllers, contactors and certain heating or irrigation systems.
The switched circuit still has to remain within Shelly’s published electrical ratings.
Dry contacts do not remove the need for correct electrical design.
It can work with AC and DC power
Shelly specifies several supply options for the 1 Gen3.
The device supports:
- 110–240V AC
- 24–48V DC
- 12V DC
That flexibility expands the number of applications in which the relay can be installed.
A household lighting circuit may use normal mains power, while a garage-door or gate-control installation may use a low-voltage DC system.
The device consumes less than 1.2W according to Shelly’s current specification.
The relay is rated up to 16A on AC resistive loads
Shelly rates the relay for up to 16A at 240V AC and 10A at 30V DC.
That maximum should not be interpreted as a target for every application.
Load type matters.
Shelly specifically notes that the 16A figure applies to resistive loads. Motors, LED drivers and other inductive or capacitive loads can behave very differently during switching and may require additional protection such as an appropriate RC snubber or contactor.
This distinction is important in a South African home.
A device may appear to be comfortably below 16A during normal operation while producing very different electrical conditions during startup.
Installers should therefore size the switching arrangement for the actual equipment rather than simply looking at the largest number on the relay specification.
Matter support is now available
One of the biggest changes for the Shelly 1 Gen3 is Matter.
Shelly confirms that Matter support is available from firmware 1.6.0 or newer.
Matter is intended to make compatible smart-home devices easier to integrate across ecosystems.
That can reduce dependence on a single manufacturer when a home contains equipment from several brands.
For Shelly users, Matter sits alongside the company’s existing integrations rather than replacing them.
The 1 Gen3 also supports Amazon Alexa, Google Home, Samsung SmartThings and broader automation platforms.
That gives owners several ways to decide how deeply they want Shelly’s own app involved.
No dedicated hub is required
The Shelly 1 Gen3 connects directly to Wi-Fi.
A dedicated Shelly hub is therefore not required for normal operation.
This can significantly lower the barrier to starting a smart-home project.
Someone can install one relay for a specific purpose without first buying a central controller.
As the installation grows, those devices can later form part of a larger smart-home system.
This modular approach is one reason embedded relays appeal to enthusiasts.
The first project could be one outside light.
The next could be a gate, irrigation valve or extractor fan.
The homeowner does not have to automate the entire property at once.
Local control reduces dependence on the internet
Cloud access is convenient, but a smart home becomes frustrating if everything stops working because the internet connection disappears.
Shelly confirms that the 1 Gen3 can operate on the local Wi-Fi network without internet access.
Its embedded web interface and local integrations such as MQTT can continue functioning locally. Internet connectivity is needed for remote access and cloud-dependent features.
This is particularly useful for more advanced home-automation installations.
A locally hosted Home Assistant system, for example, does not necessarily need every command to travel through an external cloud service before a light can switch on.
Local automation can also reduce latency and remove one external dependency from everyday functions.
MQTT and scripting open the door to advanced automation
The Shelly 1 Gen3 goes considerably further than simple app-based on/off control.
It supports:
- scripting,
- MQTT,
- webhooks,
- WebSocket,
- HTTPS,
- UDP,
- TLS,
- custom certificates.
Shelly also provides 20 schedules and up to 20 webhooks, with multiple URLs available per hook.
Most households will never use all of those capabilities.
However, they are valuable for enthusiasts and professional installers.
A relay can become part of a larger automation rather than operating as an isolated smart switch.
For example, a sensor event could trigger a script, which then changes another device or sends information to a home-automation server.
Wi-Fi range extension adds another function
The Shelly 1 Gen3 can also act as a Wi-Fi range extender for supported Shelly functionality.
It also operates as a Bluetooth gateway for Shelly BLU devices.
That does not mean Bluetooth becomes the normal direct control method for the relay itself.
Shelly states that Bluetooth on the 1 Gen3 is primarily used for setup and for interacting with compatible Bluetooth devices through its gateway functionality.
That distinction is worth making because simply seeing Bluetooth in a specification table can create the impression that Wi-Fi and Bluetooth offer identical control options.
They do not.
Shelly 1 Gen3 can automate existing lighting
Lighting is one of the most obvious applications.
A Shelly relay can be installed so that an existing lighting circuit becomes remotely controllable without necessarily replacing the visible wall switch.
Schedules can automatically switch lights according to time.
Shelly also supports sunrise and sunset-based schedules.
That means outside lighting could switch on around sunset and off again later without someone manually adjusting the schedule as daylight hours change throughout the year.
The physical switch can remain available for normal manual operation.
That combination is far more practical than creating a smart home that becomes impossible for visitors or other family members to understand.
Garage doors and gates are a particularly useful application
Dry contacts make the Shelly 1 Gen3 especially interesting for garage-door and gate automation.
Shelly South Africa specifically recommends the product for garage and gate applications.
Its local guidance notes that dry contacts and AC/DC supply options can allow compatible gate motors and garage-door systems to be controlled remotely.
Additional hardware can expand the installation.
For example, Shelly describes using its Add-On with a reed switch to determine whether a garage door is currently open or closed.
That is more useful than simply sending an open/close command.
Remote control is considerably safer when the user can also establish the current state of the door.
Compatibility still needs to be checked against the particular gate or garage-door controller.
Smart irrigation is another South African use case
Irrigation is another application highlighted by both Shelly internationally and Shelly South Africa.
A suitable relay installation can switch compatible irrigation equipment according to a schedule.
Shelly can also incorporate weather information into more advanced automations.
The idea is straightforward.
Watering does not need to occur simply because the clock reaches a particular time.
Automation could consider other conditions before activating a system.
That is particularly interesting for South African gardens where watering schedules, seasonal rainfall and water restrictions can make unnecessary irrigation undesirable.
The Shelly itself is not a weather sensor, however. Those more advanced decisions rely on additional data and automation logic.
Existing appliances can gain basic smart control
Shelly South Africa also positions the 1 Gen3 for controlling compatible household equipment.
That could include certain fans, heaters, entertainment systems and other electrical loads.
The important word is compatible.
A relay can control electrical power or a compatible control input.
It cannot magically add digital functions to an appliance.
If a device requires someone to press an electronic start button every time power returns, simply switching its supply off and on may not achieve much.
The appliance’s own operating behaviour needs to be understood before deciding whether relay automation makes sense.
Shelly 1 Gen3 does not measure energy consumption
This is an important limitation.
The Shelly 1 Gen3 does not provide power monitoring.
It can control a circuit, but it is not designed to tell the owner how many watts that circuit is drawing or how much electricity it has consumed.
That distinction separates it from Shelly’s 1PM products, where the “PM” refers to power measurement.
Buyers should therefore choose the model according to what they actually need.
If the goal is purely switching and dry-contact flexibility, the 1 Gen3 makes sense.
If energy monitoring is essential, a suitable Shelly PM model deserves consideration instead.
TechnologyBlog recently looked at another approach to appliance energy tracking in our Govee Smart Plug Pro coverage.
Read TechnologyBlog’s Govee Smart Plug Pro energy-monitoring article
The two products address different installation styles. The Shelly is an embedded relay, while the Govee article illustrates the plug-in approach to monitoring individual appliances.
Gen3 brings more memory
The new ESP-Shelly-C38F processor is paired with 8MB of flash memory.
Shelly says Gen3 doubles the memory available compared with the preceding Plus generation.
More memory matters less because of one visible feature and more because it gives firmware and local applications additional room to develop.
Matter support is a good example.
The Gen3 architecture was designed with newer integrations and firmware capabilities in mind rather than being restricted to the feature set available when the hardware first shipped.
Shelly 1 Gen3 supports KNXnet/IP
Shelly also lists KNXnet/IP communication among the 1 Gen3’s supported capabilities.
KNX is particularly relevant in more sophisticated home and building-automation environments.
For a basic household installation, this may never matter.
For integrators, commercial environments or homes already using a broader building-control platform, the presence of additional protocols increases the number of ways the relay can fit into an existing system.
That flexibility is a recurring theme with Shelly.
The company is not relying exclusively on its own mobile application to make the hardware useful.
The relay can operate in a wide temperature range
Shelly specifies an operating temperature range of approximately -20°C to 40°C and relative humidity between 30% and 70%.
The maximum specified operating altitude is 2,000 metres.
Johannesburg sits at high altitude, so the 2,000-metre specification is worth noticing even though typical Johannesburg elevations remain below that maximum.
Installation conditions still matter.
The device needs to remain within its environmental specification and be installed inside an appropriate enclosure.
A tiny smart relay should not simply be left exposed to rain, dust or physical damage because it is being used for an outdoor light or gate.
South Africans have official Shelly distribution
This is where the Shelly 1 Gen3 has an advantage over many smart-home devices discovered through overseas storefronts.
Shelly has a dedicated South African operation.
Shelly SA states that Nology is the official distributor of Shelly products in South Africa, supplying products through authorised resellers and installers.
That means the device is not simply an overseas product that happens to support 230V.
There is a recognised local distribution and installer channel.
Shelly SA also lists the 1 Gen3 specifically in local automation examples covering bedrooms, bathrooms, gardens, kitchens, garages and gates.
South African pricing is deliberately not included in this article.
Installation needs to be taken seriously
The Shelly 1 Gen3 is physically small, but some of the circuits it can control are not.
A 230V household circuit can cause serious injury, fire or equipment damage if wired incorrectly.
Users should not interpret the small enclosure or app-based setup as meaning installation is equivalent to plugging in a smart bulb.
Correct conductor size, circuit protection, terminal tightening, enclosure space, load type and wiring arrangement all matter.
Where an installation involves fixed mains wiring, the work should be carried out in accordance with applicable electrical requirements by someone appropriately qualified to perform it.
The Shelly wiring diagram and safety documentation should be followed for the exact supply configuration being used.
Who is the Shelly 1 Gen3 for?
The Shelly 1 Gen3 makes sense for people who want to add smart control while retaining existing switches or electrical equipment.
Its dry contact is particularly useful where the relay needs to control a separate compatible circuit.
Home Assistant enthusiasts should appreciate MQTT, scripting and local-network operation.
Less technical users can stay primarily inside the Shelly Smart Control app and supported voice-assistant ecosystems.
Professional installers gain a compact relay with several supply options and broad integration support.
However, it is not the correct Shelly for every project.
Anyone who needs power monitoring should look at a suitable PM model.
Projects involving multiple channels, DIN-rail mounting or specialised motor control may also benefit from a different Shelly product.
Is the Shelly 1 Gen3 worth considering?
The Shelly 1 Gen3 is interesting precisely because it does not require an entire smart-home redesign.
It can sit behind existing electrical systems and add connected control to equipment that was never designed to be smart.
Dry contacts considerably expand its usefulness, while support for 110–240V AC, 12V DC and 24–48V DC gives installers several power options.
Wi-Fi means a dedicated hub is unnecessary.
Matter, Alexa, Google Home, SmartThings, MQTT, scripting and local control provide several paths for integration.
The absence of energy monitoring is the main specification buyers need to understand before choosing it over another Shelly model.
For South African users, official local distribution through Nology makes the proposition stronger.
Instead of importing an electrical device and hoping it fits the local environment, buyers have access to Shelly’s established South African reseller and installer network.
For the right automation project, that combination of compact hardware, dry contacts and unusually open software integration gives the Shelly 1 Gen3 considerably more flexibility than its tiny blue enclosure suggests.
Shelly 1 Gen3 specifications
| Specification | Shelly 1 Gen3 |
|---|---|
| Device type | Wi-Fi smart relay |
| Model | S3SW-001X16EU |
| Relay channels | 1 |
| Contacts | Potential-free / dry contact |
| AC supply | 110–240V AC |
| DC supply | 12V DC or 24–48V DC |
| Maximum AC switching | 16A at 240V AC |
| Maximum DC switching | 10A at 30V DC |
| Power consumption | Under 1.2W |
| Wi-Fi | 802.11 b/g/n |
| Bluetooth | Bluetooth 4.2 LE |
| Matter | Yes, firmware 1.6.0+ |
| Alexa | Yes |
| Google Home | Yes |
| Samsung SmartThings | Yes |
| MQTT | Yes |
| Scripting | Yes |
| KNXnet/IP | Yes |
| Webhooks | Yes |
| Local operation | Yes |
| Hub required | No |
| Wi-Fi extender | Yes |
| Bluetooth gateway | Yes |
| Energy monitoring | No |
| Internal temperature sensor | Yes |
| Flash memory | 8MB |
| Dimensions | 37 × 42 × 16mm |
| Weight | 26g |
| Operating temperature | -20°C to 40°C |
| Official South African distribution | Yes, via Nology |
