# Software, Control, Safety and Certification

# Dry Contact

# Is the dry contact certified according to SIL 1 or SIL 2?

No, it should only be used to shut down the electrolyser as a preliminary measure, before a real safety risk occurs. To realize a true safety shutdown, please use a certified safety circuit and simply cut off the power to the electrolyser.

For example, in the case of a hydrogen leak, a H₂ safety sensor could ring an alarm and trigger the dry contact at a warning threshold of 10% of LEL to shut down the EL. If a safety threshold of 25% LEL is reached, it could trigger a certified safety circuit to cut the power to the entire system.

# What happens in case of hydrogen leakages or a pressure drop?

Enapter's electrolysers have various sensors to ensure a safe operation at all times. If a leak is detected or the pressure unexpectedly falls, the electrolyser will shut itself down and send an error message via the Enapter Management System (EMS). The maximum amount of hydrogen gas inside one electrolyser is around 18 NL. An internal ventilation system dilutes any possible leakages below the hydrogen lower explosive limits (LEL).

# What safety features are integrated in Enapter’s electrolyser?

Enapter's electrolyser is designed to be intrinsically safe. It self-pressurises the hydrogen side and performs leak test routines at regular intervals. Electrolysers from generation EL2.1 (opens new window) on are CE certified, which allows straightforward integrations into existing safety concepts. In some cases, it might be necessary to install additional safety devices (e.g. hydrogen detectors on the top of the cabinet) to satisfy local regulations and safety concepts. These hydrogen detectors can be connected with the dry contact on the front panel. It is recommended to define two safety levels (e.g. at 10% and 25% of the lower explosive limit):

  1. For 10% LEL: Trigger the dry contact for a safe shutdown.
  2. For 25% LEL: Cut off the power directly.

# Software Control

# What is the Enapter Energy Management System?

Enapter is constantly expanding its Energy Management System Toolkit, which it provides to all customers. The EMS Toolkit allows integrators to create a comprehensive Energy Management System (EMS), connecting any hydrogen or energy device into a unified energy network via simple hardware and software integrations. It thus enables monitoring and control of energy systems of any size and shape. Its tools include Universal Communication Modules (UCM), the Enapter Telemetry Platform, the Enapter Cloud and our Mobile App. The EMS Toolkit also offers developer tools like Web IDE and Enapter Blueprints, as well as documentation to help system integrators and component manufacturers add our solutions to their products.

# Where can I look up the meaning of an error code or warning that is displayed in the app or cloud?

A table of error codes and their meaning can be found here (opens new window). Please look up the firmware version of your device before searching for the error or warning as those might change depending on the firmware version.

# Can I use Enapter products also without WiFi?

Yes. The electrolyser, dryer, water tank and water purification system also work without WiFi. However, for the initial setup it is mandatory to connect them to a network and add them to a virtual customer site. Please note that not all functionalities may be available without WiFi.

# Which data can be monitored?

The Enapter Management System (EMS) allows tracking of warning and error messages, inlet and outlet pressures, production volume and more. It can be accessed by any standard internet browser, such as Google Chrome and Firefox. Specific data sets can be downloaded in CSV format with a few clicks on the exports page.

When using Modbus, the same data can be read out via scripts and the same commands available in the EMS are also available via Modbus.

# Can I adapt the Enapter Management System (EMS) to an individual setup?

Yes. The EMS can be adapted to read and write data from all common communication standards of micro-grid systems and analogue inputs. If you would like to integrate a new system (inverters/power meters/fuel cells) into the EMS ecosystem, feel free to contact us!

# Is it possible to monitor the water inlet?

The water quality is not analysed. Depending on the supplied water, suitable maintenance intervals can prevent a decreasing water quality and damage of the electrolyser.

However, a sensor at the electrolyser's inlet ensures that the pressure is between 1 bar and 4 bars. If it does not detect water for a longer time, the electrolyser will stop the hydrogen production and wait for a higher water input pressure. Warnings and water pressure can be monitored via the Enapter Management System (EMS).

# Is it possible to switch the system on and off and controlling the hydrogen pressure, flow regulation, etc. remotely?

Yes. The Energy Management System allows full monitoring and control via a website or mobile phone app. It also allows for efficient support and service.

# Is it possible to use a PLC to send commands to the equipment?

Yes. Individual electrolyser can be interfaced to a PLC using Modbus TCP/IP and the electrolyser’s Ethernet port. A group of devices set up on a site with an Enapter Gateway can be interfaced to a PLC via an MQTT connection to the Enapter Gateway.

# Is there a possibility to smart regulate the production?

Yes. Due to the rule based control, the system can be programmed to be as versatile as needed. In that way, weather and time depending control and other sensor driven actions can be realized by a simple CLI 1 if-then-else logic. For an extended functionality and more complex situations, the scripting language Lua can be used. Generally, for rule based control, the Enapter Gateway is needed.

# What are the advantages of the Enapter mobile phone app?

Enapter's mobile phone application is an interface for system integrators and end-users who want to connect their devices such as electrolysers, dryers, communication modules and extensions. The Enapter mobile phone app allows an easy and secure system setup using QR codes to manage and monitor devices all over the world. It is available for Android and iOS.

# Can the electrolyser be switched off in case of an emergency? How long does it take to switch the electrolyser on again?

Yes, of course, in case of an emergency, the power to the electrolyser can just be cut off. When the emergency is resolved, the electrolyser can be powered on and restarted again within a few minutes.

# Can the electrolyser be managed without the Enapter mobile phone application or Cloud?

Yes. However, the most convenient and simple way to manage and monitor the electrolyser is via the Enapter Cloud or mobile phone app.

When using the Modbus TCP interface all required data and functionality for the integration with third party management software is possible. Enapter provides a full Modbus register table (here (opens new window) for the EL 2.1) together with samples of programming scripts in python to get started. The scripts are hosted on a github (opens new window) page and help to understand the flows of monitoring, control and commissioning of the device.

# Are there updates available for the Enapter devices?

Yes. They can be downloaded and installed via the mobile phone app or the cloud.

# What is Modbus TCP/IP and how can I use it to control the Enapter devices?

Modbus TCP/IP is a protocol which can be used to access registers of the electrolyser via the Ethernet port. This can be used to read statuses and sensor data as well as to write commands like start, stop, reboot. A description of all available registers can be found here.

# Certification

# Is the electrolyser CE certified?

The EL2.1 (opens new window) is CE certified.

# Is the electrolyser ATEX2certified?

Our products are not designed to be installed in an ATEX area, and do not create explosive atmospheres when installed correctly. The output gases are only released from the designated interfaces (H₂ outlet, O₂ vent, and H₂ purge). These have to be correctly managed during the on-site installation. It is the operators responsibility to ensure that the area where the electrolysers are installed must never contain any explosive atmospheres. An appropriate safety concept must be implemented to mitigate the risks of any failures and consequences of leakages of flammable gases. Such a safety concept could involve, for example, hydrogen sensors, forced ventilation, or natural ventilation.

# Is the piping system in accordance with a certification?

Yes. Enapter designs all hydrogen piping in accordance with ASME B31.12. All European guidelines refer to the ASME, which are very high standards for hydrogen piping and pipelines.

# Which countermeasures are necessary to prevent the creation of an ATEX area around the electrolyser?

The electrolyser has a standard ¼" Swagelok bite-type Stainless Steel connector for the hydrogen outlet piping. Internally it is protected by relief and check valves to prevent backflow of external tank/H₂ distribution lines. In some few cases, local rules or regulations require welding.

However, it is usually sufficient to keep the oxygen outlet and the purge line separated and apart from ignition sources.


1: Command Line Interface

2: Atmospheres Explosibles