2. Installation and connection

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Installation and connection

Installation procedure

Overall and mounting dimensions of the BMS Main 2.1 are shown below.

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ParameterValue
Overall dimensions (length × width × height), mm120 × 120 × 32
Mounting dimensions (length × width), mm114 × 114
Mounting holesM3

Connection procedure

The mounting area of the BMS Main 2.1 must be protected from mechanical particles (dust, dirt, large objects) and water. The installation site must provide convenient access for subsequent connection to the device’s headers.

  1. Connect the charging and discharging contactors to the P6-P9 headers.
  2. Connect a current sensor to the P12 header according to its documentation. The positive current direction (indicated by an arrow on the sensor) corresponds to the battery charging. It is recommended to use a shielded cable to connect the current sensor, the shield should be grounded on the side of the current sensor. The cable should be positioned as far as possible from the high current circuits. If the current sensor has a reference voltage line, connect it to pin 4 of the P12 header.
  3. Connect the BMS Main 2.1 to the on-board CAN network. Observe the rules for connecting CAN devices. If the BMS Main 2.1 is the last device on a bus, close pins 1-2 on the P21 jumper, otherwise leave the jumper on pins 2-3.
  4. Connect a power supply to the P1 header. It is not recommended to power the BMS Main 2.1 from the battery only, since at a critical discharge of the battery, it is not possible to turn on the BMS and close the charging contactor.

​​​​Headers description

The BMS Main 2.1 headers are shown in figure below.

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Attention!
All headers are shown from the device side!

P1 – header for power supply

Receptacle Housing: Molex 39012020. Terminals: Molex 5556

1732198827034-560.png

PinNameDescription
1GNDGround
2V+Supply voltage 9-30V

P15 – header for BMS Logic

Receptacle Housing: Molex 430250400. Terminals: Molex 43030

1732198890482-787.png

PinNameDescription
1RS485_ARS-485 line A for communication with BMS Logic
2RS485_BRS-485 line B for communication with BMS Logic
3+5VSupply voltage for BMS Logic
4GNDGround

P12 – header for current sensor

Receptacle Housing: Molex 430250400. Terminals: Molex 43030

1732198890482-787.png

PinNameDescription
1+5VSupply voltage for the current sensor 5V, max 50 mA
2GNDGround
3VcsADC input (current sensor output)
4VrefADC input (current sensor reference signal)

P13 – header for humidity sensor

Receptacle Housing: Molex 430250400. Terminals: Molex 43030

1732198896526-660.png

PinNameDescription
1+5VSupply voltage 5 V, max 50 mA
2GNDGround
3VhsADC input (humidity sensor output)
4VtsADC input (temperature sensor output)

P8 – header of relay 1

Receptacle Housing: Molex 39012020. Terminals: Molex 5556

1732198827034-560.png

By default, relay 1 is used to control the discharging contactor.

PinNameDescription
1V+Switching voltage (up to 55V, max 3A)
2NONormally open contact

Contactor connection example for all relays:

1741619814065-850.png

P9 – header of relay 2

Receptacle Housing: Molex 39012020. Terminals: Molex 5556

1732198827034-560.png

By default, relay 2 is used to output the “Allow charging” signal.

PinNameDescription
1V+Switching voltage (up to 55V, max 3A)
2NONormally open contact

Contactor connection example: see relay 1.

P6 – header of relay 3

Receptacle Housing: Molex 39012020. Terminals: Molex 5556

1732198827034-560.png

By default, relay 3 is used to control the charging contactor.

PinNameDescription
1V+Switching voltage up to 55V,
up to 8A (board rev. 2.1b), up to 3A (board rev. 2.1c)
2NONormally open contact

Contactor connection example: see relay 1.

P7 – header of relay 4

Receptacle Housing: Molex 39012020. Terminals: Molex 5556

1732198827034-560.png

By default, relay 4 is used to control the heater.

PinNameDescription
1V+Switching voltage up to 55V,
up to 8A (board rev. 2.1b), up to 3A (board rev. 2.1c)
2NONormally open contact

Contactor connection example: see relay 1.

P14 – header for CAN and RS-485 interfaces

Receptacle Housing: Molex 430250600. Terminals: Molex 43030

1731517180930-597.png

PinNameDescription
1EXT_RS485_ARS-485 line A for communication with external equipment
2CAN_HCAN H line for communication with external equipment
3+5V_CANSupply voltage 5V for external devices, max 200 mA
4EXT_RS485_BRS-485 line B for communication with external equipment
5CAN_LCAN L line for communication with external equipment
6GND_CANGround

P21 – CAN termination resistor jumper

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To connect the termination resistor between the lines CAN_H and CAN_L, install a jumper, according to the P21 pinout:

PinNameDescription
1-2120 OhmTermination resistor 120 Ohm is connected
2-3-Termination resistor 120 Ohm is not connected

P22 - RS-485 termination resistor jumper

1731517195672-298.png

To connect the termination resistor between the EXT_RS485_A and EXT_RS485_B lines, install a jumper according to the P22 pinout:

PinNameDescription
1-2120 OhmTerminating resistor 120 Ohm is connected
2-3-Terminating resistor 120 Ohm is not connected

P11 – header for discrete inputs/outputs

Receptacle Housing: Molex 430251600. Terminals: Molex 43030

1732198937514-731.png

PinNameDescription
16IN_1Discrete input #1 “dry contact” (+5V)
8GND_1Discrete input #1 “dry contact” (ground)
15IN_2Discrete input #2 “dry contact” (+5V)
7GND_2Discrete input #2 “dry contact” (ground)
14IN_3Discrete input #3 “dry contact” (+5V)
6GND_3Discrete input #3 “dry contact” (ground)
13IN_4Discrete input #4 “dry contact” (+5V)
5GND_4Discrete input #4 “dry contact” (ground)
12OUT_4Discrete output #4 (+5V, 20mA)
4GND_OUT_4Discrete output #4 (ground)
11OUT_3Discrete output #3 (+5V, 20mA)
3GND_OUT_3Discrete output #3 (ground)
10OUT_2Discrete output #2 (+5V, 20mA)
2GND_OUT_2Discrete output #2 (ground)
9OUT_1Discrete output #1 (+5V, 20mA)
1GND_OUT_1Discrete output #1 (ground)

Indicators

DS1 – power indicator

StateDescription
Lights redThe device is powered
OffThe device is not powered

DS2 – operation indicator

StateDescription
Blinking greenThe BMS firmware is running
OffThe BMS firmware is not running

DS3 – communication indicator

StateDescription
Blinking yellow (2Hz)Initializing communication with BMS Logic boards
Blinking yellow (25Hz)Communication with BMS Logic is established

DS4 – error indicator

(StateDescription
(Blinking redErrors in communication with BMS Logic

DS7 – relay 1 indicator

StateDescription
Lights greenRelay #1 is closed
OffRelay #1 is opened

DS8 – relay 2 indicator

StateDescription
Lights greenRelay #2 is closed
OffRelay #2 is opened

DS5 – relay 3 indicator

StateDescription
Lights greenRelay #3 is closed
OffRelay #3 is opened

DS6 – relay 4 indicator

StateDescription
Lights greenRelay #4 is closed
OffRelay #4 is opened