The Eaton APS3 / SC200 system controller is a popular DC power solution used by Australian Telecommunications companies to manage their off-grid power.  These power systems often rely heavily on diesel generation to supplement the solar output - or alternatively, they often have over-specified batteries and solar setups to achieve high up-time.  As a result, there is a growing demand for our Hyland 920 small wind turbine to be added to the Eaton APS SC200 power mix.

This short article will outline the quick and easy 3-step process for integrating the Diffuse Energy MkII controller with the Eaton APS3 – sub rack with the SC200 system controller.

Integration – step 1.

The first step is to find the existing battery shunt reader on the Eaton system that has two RJ45 ports. One of these ports is always occupied and leads back to the IO board - the second port is a daisy chain connection for additional current readings.

To connect with the Diffuse controller, you need to:

1. Install a Shunt at the back of the cabinet (there is generally plenty of room). We used a 50A / 60mV.
2. Separate the cores on the shunt end of the Cat5 and plug the other end into the Eaton card
3. Setup the monitoring in the SC200

The wind turbine current (if turbine is operating) will now begin flowing through the shunt and into the APS3 DC bus – which will be registered by the Eaton controller. This will present as an ‘Alternate Energy’ source.

IMPORTANT: The wind turbine shunt must be wired on the solar controller output bus before the battery shunt, otherwise the readings will calculate incorrectly.

NOTE: Typically the LVD (low voltage disconnection - prevents battery over-discharge) is on the battery side for AC mains application, but for solar it is moved to the load side to disconnect the load (so that the controller is never turned off).

Integration – step 2.

As shown in the diagram below, the shunt is connected to pins 1 and 2 of the Cat5.

NOTE: Make sure you do not allow any of the unused Cat5 wires to short on each other when you separate them to connect to the shunt.

Integration – step 3.

Once the shunt is connected, the last step is to add the additional analogue input into the Eaton SC200 programming.  This line will appear automatically and should be named as ‘Wind’. Refer to line 7 of the image below.

NOTE: The gain is determined by the shunt scaling.