******************
Powering a Gateway
******************

Power options Gateway E32, E32 V2, S32, S3 and S32-LR
=====================================================

Service jack
------------

If your boiler or heatpump has a service jack, just connect the Gateway with the EMS service cable.
The service jack has pins for both the EMS bus and an additional power supply for peripherals.
You do not need to add an external power supply in this case.

.. warning::
  Do not use cheap audio cables for connecting a Gateway to the service jack of the boiler/heatpump.
  Most of them have very thin wires inside, this may cause lots of interference and it is a possible fire risk.
  The EMS service cable from the webshop is a high quality cable with thicker wires inside.

Splitting service jack power
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If you have f.i. a KM50 module already on the service jack, then you can split the jack connector with a 3,5mm audio splitter.
This method is not recommended and it may not always work, but you can try. 
Use a high quality connector type splitter and not one with long cables attached as these cables are intended for audio and thus have very thin wires inside.
Turn off the Gateway/KM50/boiler, connect them all and them turn on the boiler again.

If the KM50 or the Gateway does not work via the splitter cable, you need to remove the splitter and connect the Gateway to the BUS terminal and add an external power supply.

.. image:: ../images/hardware/audio-splitter-1.jpg
  :width: 150
  :alt: audio splitter

External power supply
---------------------

If your boiler does not have a service jack, or it does but you want to mount the Gateway elsewhere, you need to use an external power supply.
A suitable power supply is optional when buying a Gateway. If you want to use your own, see the specifications in the table below.

.. image:: ../images/hardware/dc-barrel-jack-supply.jpg
  :width: 200
  :alt: DC power supply

USB port
--------

Although the enclosure is not designed for this, Gateway models S32 and S32-LR can also be powered from the internal USB port for testing purposes.
Remove the side piece of the enclosure to make use of the USB port.
The internal USB port inside the E32 V1.0 to V1.5 cannot be used to power the Gateway. It is only intended for firmware flashing.

The external USB-C port on the E32 V2, the S3 and S3-LR is also intended for firmware flashing only.

Power requirements external DC power supply
===========================================

If you want to use your own power supply with a Gateway, it needs to have the following minimum requirements:

.. list-table::
   :header-rows: 1

   * - Parameter
     - Specification
   * - Voltage output
     - 12V DC
   * - Current output
     - 200mA or more (>500mA recommended)
   * - Plug
     - DC barrel jack 5,5mm (2,1mm center pin)
   * - Polarity
     - center pin positive  

It's recommended to use a high quality power supply. You can buy a good one from the BBQKees webshop.
Alternatively one that was included with an old router for instance will work well.
Do not use a cheap power supply from Aliexpress or Ebay, as they may introduce noise on the EMS bus.
I do not give support on orders if you decide to use a crappy power supply.


Power options Gateway Premium II
================================

For the older Premium II Gateways there are three options to power the device.

Service jack
------------

See information above.

Bus power
---------

The Premium II can also be powered from the EMS bus itself. Just connect the two EMS bus wires to the screw terminal.
If the Gateway does not work, or does not work well you need to add a USB power supply.

USB port
--------

Although the enclosure is not designed for this, the Premium II can also be powered from the internal USB port.
Remove the side piece of the enclosure to make use of the USB port.