S6-EH3P(5-10)K-H-EU - BMS BUS testing

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S6-EH3P(5-10)K-H-EU - BMS BUS testing

Introduction

Ensuring proper communication between the Battery Management System (BMS) and the inverter is crucial for the seamless operation of your system. In this guide, we will outline steps to check the CAN Bus communication, focusing on verifying voltage presence on the CAN Bus on the inverter side.

Content

• Check BMS Connection
• Address Alarms
• Testing CAN Bus Voltage
  1. Getting to know bus assignment
  2. Establish bus assignment and assign colors
  3. Stripping the bus lines and tinning
  4. Checking voltage on BUS 

Check BMS Connection

Before testing the CAN Bus, ensure that the BMS is correctly connected to the inverter. Refer to the manufacturer's manual or relevant documentation for proper connection instructions. If needed, consult resources like this article for guidance - https://solis-service.solisinverters.com/a/solutions/articles/44002484785?lang=en

Address Alarms

If you encounter "CAN COM Fail" or "No Battery" alarms, verify that the correct battery model is configured on the inverter and ensure the proper pins are used for communication setup. If alarms persist despite these checks, proceed with testing the CAN Bus.

Testing CAN Bus Voltage

Getting to know bus assignment

The S6-EH3P(5-10)K-H-EU utilizes an RJ45 socket. Refer to the table below, where you'll notice that PIN 4 and 5 are designated for communication between the battery and the inverter (CAN H and CAN L).

Establish bus assignment and assign colors

In this step, it's essential to ensure that you choose the correct colors. Take a look at your CAT cable and verify the color assignment for PINS 2, 4, and 5. In our case, we have the following colors for these PINS:

PIN 2 = Ground – Colour ORANGE 

PIN 4 = CAN H – Colour BLUE-WHITE  

PIN 5 = CAN L – Colour BLUE

Stripping the bus lines and tinning

Before testing, ensure that you strip the insulation properly from the bus lines. We recommend tinning the ends to ensure proper contact.

Checking voltage on BUS 

Step 1: 

Set your Multimeter to DC Voltage mode. Ensure that the black cable is connected to the "COM" port and the red cable is connected to the "V" port. Also, verify that the inverter is switched ON.

Step 2: 

Measure the voltage between GND and CAN L (in our case BLUE). The multimeter display should show a value between 2 and 5 Volts. 

Step 3:

Measure the voltage between GND and CAN H (in our case BLUE/WHITE). The multimeter display should show a value between 2 and 5 Volts.

Step 4: 

The BUS test has been successfully completed. If all values displayed are as expected, the inverter should be capable of sending and receiving information from the Battery BMS. You can now insert the tinned wire ends, clamped into the appropriate terminal strip according to the specifications of the battery manufacturer.

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