Last updated on Mon 09 Mar 2020

Technical documentation

Mount Kelvin Mesh


What is Mount Kelvin Mesh?

Mount Kelvin Mesh is a guest room management system (GRMS).

Mount Kelvin Mesh is a fully wireless system based on Wirepas and Bluetooth Low Energy (BLE in short). The main principle behind Wirepas is mesh networking, meaning the wireless devices form connections with all other surrounding devices, forming a tightly knit web that does not have a single point of failure. The messages are sent from device to device over radio, more specifically a 2.4 GHz radio similar to Bluetooth.

Why Mount Kelvin Mesh?

Compared to other systems, Mount Kelvin Mesh offers several benefits:

  • Focused on hotels. The system is designed with hotel room controls in mind. In addition to the technical system, we provide functionality and best practices specific for the hospitality industry.
  • Easy design and installation, retrofittable. The wireless nature of Mount Kelvin Mesh makes it ideal for hotel renovations and greenfield projects alike. Existing cabling does not need to be replaced and no new components are needed in the distribution cabinet.
  • Improves over time. Mount Kelvin turns your hotel into a digital platform, which evolves as technology improves and your needs evolve. Adding new services or sensors is easy, and new features are rolled out every month.
  • Operational efficiency. Mount Kelvin turns guest activity into data, which can be used to drive operational efficiency. Our open APIs allow hotels to use this data in other systems to optimize housekeeping efficiency, maintenance and power consumption.

Technical foundation

Mount Kelvin is always delivered with a cloud connected gateway, which enables updates, monitoring, configuration and controlling to be done remotely from anywhere in the world. Cloud connectivity also enables third party integrations to HVACs (heating, ventilation & air-conditioning) and BMSs (building management system). In effect Mount Kelvin turns the building into a software platform which improves over time as new features and options are added, without the need to replace the electrical infrastructure when new functionality is rolled out.

The wireless structure of Mount Kelvin makes it especially well suited for retrofits as the wireless devices either need no cabling or utilize the existing power cabling.

Mount Kelvin Architecture
A Mount Kelvin Mesh installation consists of meshed devices (drivers, sensors, switches and gateways), a cloud service with an open API and control and configuration applications.


Lighting control

Mount Kelvin is designed to provide a premium experience in lighting control. Our principle is total lighting control, which means that all luminaires in the room, including table/floor/reading lamps, are controlled by the system.

Total lighting control is the basis for the proper implementation of other features. For example, if all luminaires are not controlled by the system, pressing All off switches everything but the table lamp off, which is nothing more than frustrating to the guest.

Scene control for lighting

Using scenes as the basis of lighting control ensures consistency in the room experience: each customer enjoys the carefully designed lighting presets created by the lighting/interior designer. The All off scene provides convenience when leaving the room or going to sleep.

For our standard rooms we always create four lighting scenes: Daytime, Evening, Night, and All off. These are fully customizable for each hotel and each room type.

We recommend all luminaires to be dimmable by default. This dramatically improves the possibilities to create pleasing lighting scenes.

Night shift

Night shift automatically activates a lighting scene in the room based on motion sensor activity depending on the time of the day. There are three configurable periods of time: day, evening and night.

Welcome lights

Welcome lights is a feature which activates a lighting scene when the door is opened for the first time by the guest. This feature uses a door sensor and requires a cloud integration into the PMS (in order to have guest checkin information).

Contact with details about your PMS and we will provide information on the right strategy to implement the Welcome lights feature.

Wake-up lights

Wake-up lights activates a lighting scene with a pre-defined fade-in time at a specified time. This acts as a soft wake up call.

Motorized curtain control

Having motorized curtains brings extra comfort and a feeling of luxury to the hotel room. Motorizing curtains also improves automatic energy savings by deflecting natural light when the room is not occupied for extended periods of time.

HVAC control

An essential part of a consistent guest room experience is an easy-to-use HVAC control interface. Having the HVAC system integrated into the GRMS improves the energy efficiency of the room, since our auto-off feature automatically sets all integrated devices into standby mode when the room is unoccupied.


Instead of relying on key card readers (which are commonly bypassed by having two keycards), Mount Kelvin uses motion detectors and magnetic door sensors to establish the occupancy of the room.

When a guest leaves the room and the door closes, a countdown begins. If no movement is detected during the countdown period (typically 30 mins), the occupancy state is set to unoccupied. This, in turn, then causes the lights to be switched off and the AC set to standby mode.

When the door is opened or movement is detected in the room, the occupancy state is set to occupied.

For integration purposes, the occupancy state is available via our cloud API.


The DND/MUR state can be toggled by a wireless switch from the room. This removes the need for cardboard DND/MUR signs which are hanged on the door knob. Clicking the switch alters the DND/MUR state of the room, which can be visualized by a marker light on the corridor, which in turn helps the cleaning personnel to optimize their work routines.

For integration purposes, the DND/MUR state is available via our cloud API.

Cloud connectivity

By default, all Mount Kelvin buildings and rooms are accessible via our cloud API. All integrations are far faster to implement and easier to maintain when comparing with traditional systems. Being by default cloud-connected ensures that the rooms is future-proof in terms of new technologies emerging over the lifecycle of the rooms (typically 10–15 years).

Electrical design guide

From the room controls perspective, each hotel room consists of the following components:

  • luminaires (typically not provided by Mount Kelvin)
  • luminaire drivers
  • sensors
  • switches

Please note that there are no room control components in the electrical boxes of the room. All rooms are controlled with building wide gateways, which are not positioned in the rooms. See Gateways.


Below is a diagram with luminaires in a standard room (blue symbols). There are five types of luminaires in the room:

  • ceiling-mounted downlights
  • ceiling-mounted decorative lights
  • wall mounted lights
  • floor/table lamps
  • LED strips
Electrical drawing, luminaires

Luminaire drivers

Every luminaire needs a driver in order to be controlled by Mount Kelvin. There are four types of luminaire drivers:

  • 230 VAC dimmable drivers (AC)
  • 230 VAC relays (RE)
  • constant current drivers (CC)
  • constant voltage drivers (CV)

All luminaire drivers need only mains power wiring, so no bus wiring needs to be designed.

Below is a diagram where every luminaire is accompanied by a driver (red symbols).

Electrical drawing, luminaires and drivers

230 VAC dimmable drivers

Trailing edge 230V dimmable driver Helvar ACD-FD with built-in wireless control module is suitable for dimming decorative luminaires, reading lights and other light sources which use conventional light bulbs.

Helvar ACD-FD

Data sheet for Helvar ACD-FD

When using ACD-FD, the bulbs used must be dimmable. As a rule of thumb, conventional incandescent and halogen bulbs always dim well. For LED bulbs, check dimmability from the bulb manufacturer’s documentation. Compact fluorescent (CFL) bulbs cannot be dimmed, they should always be replaced with dimmable LED bulbs. If a CFL bulb must be used, it should be controlled with a relay.

230 VAC relays

In the rare case of non-dimmable luminaires, the NodOn SIN-2-1-BLE 230 VAC relay should be used. Relays are also used on some specialty devices like smart glass.

Helvar ACD-FD

Constant current drivers

Constant current drivers are used primarily for ceiling mounted downlights. Helvar N-FD wireless control module is designed to be used with compatible Helvar constant current drivers.

Helvar Constant Current driver with communications node attached
Helvar N-FD is a wireless control module designed to be used with compatible Helvar constant current drivers.

Data sheet for Helvar N-FD

Compatible constant current drivers:

Model Power Casing Current range Link
LC25-FD-350-700 25 W Compact 350 – 700 mA Product Page
LC35FD-700-1050 35 W Compact 700 – 1050 mA Product Page
LC50FD-900-1400 50 W Compact 900 – 1400 mA Product Page
LL10-42FD-120-350 42 W Linear 120 – 350 mA Product Page
LL23-80FD-150-350 80 W Linear 150 – 350 mA Product Page
LL50FD-100-1400 50 W Linear 100 – 1400 mA Product Page
LL80-FD-350-700 80 W Linear 350 – 700 mA Product Page
LL110-FD-350-700 110 W Linear 350 – 700 mA Product Page
LL150-FD-350-700 150W Linear 350 - 700mA N/A

Constant voltage drivers

Constant voltage drivers are primarily used to control LED strips in hotels. The strips may come in various color variants, commonly: white, tunable white, RGB and RGBW. The driver package for an LED strip consists of two parts, the main driver and the 4 channel wireless control module.

Helvar LL4-CV-FD wireless control module is designed to be used with compatible Helvar constant voltage drivers. The module can be used for RGBW, RGB, tunable white and plain white lighting applications.

The CV-driver should be chosen according to the voltage and current of the luminaire, the control unit (LL4-CV-FD) supports both 12 and 24V LED strips.

Data sheet for Helvar LL4-CV-FD

Compatible constant voltage drivers:

Model Voltage Power Data Sheet
LL1x30-CV12 12V 30W Product Page
LL1x75-CV12 12V 75W Product Page
LL1x30-E-CV24 24V 30W Product Page
LL1x75-E-CV24 24V 75W Product Page
LL1x120-CV24 24V 120W Product Page
LL1x180-CV24 24V 180W Product Page

DALIMesh adapter

For some luminaires it’s not practical to replace the existing driver units with Wirepas compatible ones. Most professional luminaires are, however available with a DALI control option. The DALIMesh adapter can be use to control a single DALI device through Mount Kelvin, as if it was a full-featured Mount Kelvin compatible device.

Ensto DALIMesh
The Ensto DALIMesh takes in 230V AC power and sends DALI control signals out.

DALIMesh combines a DALI power source, a DALI communications unit and a Wirepas radio into a single compact package.


All sensors in Mount Kelvin require only mains power wiring or no wiring at all if they are battery powered. A stardard Mount Kelvin room has

  • one battery powered magnetic door sensor (∠)
  • two mains powered passive infrared motion sensors (PIR)
Electrical drawing, sensors

The bathroom sensor should be placed in a central spot in the bathroom, so that the sensor will easily detect both a person entering the bathroom as well as the areas where people are likely to remain stationary, eg. the shower and toilet seat.

The most important aspect to consider when placing the bedroom motion sensor is that the field of view covers the bed and possible sofa / living room areas.

In the case of larger rooms like suites, we recommend two or more sensors in the room to cover the bed and sofa area.

Door sensors

The Mount Kelvin wireless door sensor signals the system for changes in door state and is used for occupancy detection (together with the motion sensors) and welcome lights. It is battery powered and surface mountable with an included installation bracket. The battery life is 1-2 years with the included coin cell battery.

The sensor consists of two parts, the main sensor assembly and the magnet enclosure. The magnet enclosure may be replaced with another magnet (for example one drilled into a door).

Mount Kelvin wireless door sensor
The Mount Kelvin MK-DS-BLE is a battery powered wireless magnetic door sensor.

Motion sensors

Mount Kelvin supports standalone motion sensors from Danlers. The commonly used models are:

Model Description Data sheet
Danlers WM-CEFL Flush mount ceiling PIR motion sensor Data sheet
Danlers WM-CESR Surface mount ceiling PIR motion sensor Data sheet

Both of these devices require 230VAC power and nothing else, a radio chip inside the sensor unit handles communication.


The default control interfaces of Mount Kelvin are wireless and battery-free switches, which generate Bluetooth signals using EnOcean power harvesting technology. Since they have no wiring or batteries, they are completely maintenance-free.

The wireless switch is powered by EnOcean technology. The physical work of pushing the switch is converted to electricity, which is enough to send a BLE signal to the mesh network.

There are two types of switches in Mount Kelvin:

  • 1-key
  • 2-key

See Key configurations for supported switch configurations.

Electrical drawing, switches

Mount Kelvin recommends switches by Gira, with multiple options in switch and frame color.

We recommend anthracite colored switches with white prints for most hotel rooms, they offer a good balance with nice looks, excellent durability, readability and compatibility with various interior design ideas.

Gira wireless switches
Gira Anthracite switches with a black metal frame, white prints in 4-scenes configuration in both text and symbols.


The gateways are similarly located to wifi access points. Like a wifi access point, the only requirements are mains power and access to the internet via ethernet. Optimally, the gateway should be placed in the ceiling in an open area with few concrete or metal walls surrounding it and a large number of routing nodes (such as luminaires) surrounding it. Typically 1-2 gateways are needed per floor and the typical placement is the ceiling of a corridor.

While even one gateway is usually sufficient, we recommend reserving 3–4 installation locations for each floor to ensure good coverage, should issues arise - adding a few additional ethernet and power sockets is a good risk management measure, when new cabling is introduced anyway.

All in all, Mount Kelvin imposes very few design limitations on building electrification and infrastructure. Gateways are easy to add to the system after the fact (due to them only requiring power and Internet connectivity), should oversights in the design phase be discovered later.

Ensto DALIMesh
The Mount Kelvin gateway requires ethernet connectivity and a 230 VAC to operate.
Gateway positioning
Gateway positioning and a gateway reserve position in a typical hotel floor plan.
Gateway positioning
Gateway positioning and two gateway reserve positions in a typical hotel floor plan.

Control interfaces


Switch types

There are two types of switches: 1-key and 2-key. As the type names suggest, 1-key has one rocker key and 2-key has two. All keys are separately configurable.

One key and two key switch

Key configurations

There are six key configurations: on-off, pushdim, scene activation, four scenes, _curtain control, and DND/MUR.

On-off configuration
Pushdim configuration
Scene activation configuration
Four scenes configuration
Curtain control configuration
DND / MUR configuration


Mount Kelvin offers a fully functional webapp out-of-the-box. This webapp is fully customizable to any brand guideline and is instantly shareable via email, SMS, QR codes and NFC tags. No app installation is required with webapps.

Webapp configuration

Our webapp is has a very small data footprint, so it loads very fast and consumes very little data on the cellular data plan. To test the webapp, visit our homepage, and scan the QR code with your phone.

TV controls

Mount Kelvin offers a TV integration to hotel TV systems. The TV controls include four scenes, AC control and QR code sharing for webapp activation on guests’ mobile phones.

Currently, we support Hibox TV systems out-of-the-box. Contact to discuss support for other systems.

TV controls

Commissioning interfaces

Hotel configurator

Mount Kelvin hotel configurator is a desktop webapp for specifying the setup of the hotel rooms and public spaces. This is where the floors, rooms and their logical devices – luminaire groups, switch functionalities and sensor functionalities – are specified. These data are then converted into configurations per room.

The on-site configuration of the physical devices – called commissioning – is also done in the hotel configurator.

Hotel configurator

Networking requirements

Each Mount Kelvin gateway needs a working Internet connection via Ethernet as well as power. Networking components like switches are never offered as part of a Mount Kelvin project proposal, customer networking contractor must acquire and install these separately.

The gateways acquire IP addresses via DHCP, no manual IP assignment is needed.

All Mount Kelvin gateway units require outbound connectivity to the Internet. Notably, the network connection must be installed and fully functional prior to starting commissioning.

In a typical network no firewall changes are necessary, but if a firewall with outbound communications restrictions is present, the following ports must be open:

Direction Port Protocol Purpose
Outbound 443 TCP HTTPS to cloud backend, system updates
Outbound 29648 TCP Logging service for maintenance
Outbound 123 UDP NTP time synchronization
Outbound 53 UDP DNS (Domain Name Service)

The bandwith requirements of the gateway are relatively low, a few hundred MB / month. A more critical consideration is network latency, but this aspect is only relevant when using the mobile or web application to control the system and during commissioning. During normal operation the switches and sensors in the rooms are used as the primary control mechanism and the network connection is mostly used for status reporting and monitoring.

Security and reliability

As Mount Kelvin is a wireless and internet connected solution, special attention has been given to issues related to reliability and security of the system. In brief, a few principles have been followed in all aspects of the system:

  • Encryption of communication. Wireless and wired communications are secured against eavesdropping and message injection with strong encryption.
  • No single point of failure. Lighting control with switches will continue to work even if all gateways and many communications nodes are removed.
  • Updateable. Any connected device must be updated occasionally to remain protected against new threats.

Communication between the gateway, cloud backend and mobile app are secured with industry standard SSL encryption, similar to used in the finance industry for mobile banking. Inside the wireless mesh network, the network is secured with a pre shared network key, which is used to secure messages in the network. The initial messaging between the Mesh network and a wireless switch can also be optionally encrypted.