Specification

Main Relay

Item	Specification
Rated voltage (V)	12
Operating voltage (V)	0.5 - 9
Coil resistance (Ω)	21.6 - 26.4 [20°C (68°F)]

Pre-charge Relay

Item	Specification
Type	Mechanical relay
Rated voltage (V)	610
Rated current (A)	12

Battery Current Sensor

High Current (A)	Output voltage (V)
-750 (Charge)	0.5
0	2.5
750 (Discharge)	4.5

Low Current (A)	Output voltage (V)
-75	0.5
0	2.5
75	4.5

Component

1. Upper Case Bolt
1-a. 103.0 - 154.9 N·m (10.5 - 15.8 kgf·m, 75.9 - 114.3 lb·ft)
2. O-ring
3. Watertight Bracket
3-a. 1st : 8.8 N·m (0.9 kgf·m, 6.5 lb·ft)
3-a. 2nd : 10.8 N·m (1.1 kgf·m, 8.0 lb·ft)
4. Upper Case
5. Waterproof Gasket
6. Power Relay Assembly (PRA)
6-a. 7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

Component Location

1. Battery Current Sensor
2. Main Relay ( - )
3. Main Relay ( + )
4. Pre-charge Relay
5. Pre-charge Resistor

Description

Item	Illustration	Description
Power Relay Assembly (PRA)		It consists of a relay (main relay, pre-charge relay, pre-charge resistor) controlled by the Battery Management Unit (BMU) and a battery current sensor.
Main Relay		• The main relay is installed in the Power Relay Assembly (PRA), consists of ( + ) and ( - ) main relay. • It is the role of the connecting the high voltage battery power and the high voltage junction box by BMU control signal. • If the battery cell swells up due to overcharging of the high voltage battery cell, the main relays and the pre charge relay are cut off.
Pre-charge Relay		• The pre charge relay is installed on the Power Relay Assembly (PRA), and it connects the high voltage battery to the high voltage circuit during initial charging of the inverter capacitor. • When the IG is ON, the current, which flows through the pre charge relay and resistor, is charged in the capacitor inside the inverter. When the charging is completed, the pre-charge relay is turned OFF.
Pre-charge Resistor		The pre charge resistor is installed in the power relay assembly, and it limits the charging current to protect the high voltage circuit during initial charging of the inverter capacitor.
Battery Current Sensor		The battery current sensor is installed in the power relay assembly, and it is the sensor which measures the current when the high voltage battery is charged/discharged.

Operation

On Vehicle Inspection

   

• When working on high voltage system, the work should be performed by technicians who have completed the relevant training. A lack of understanding of the high voltage system can lead to serious accidents due to electric shock or electric leakage.

• When working on high voltage system or related components, make sure that you are familiar and comply with the "Safety Precautions, Cautions and Warnings." If you do not comply with the instructions, serious accidents due to electric shock or leakage may occur.

• When working on high voltage system, make sure to check the Personal Protective Equipment (PPE) and high voltage shut-off procedures.

Pre Charge Relay Working Test

1.Shut off the high voltage circuit.(Refer to Battery Control System (Standard) - “High Voltage Shut-off Procedure”)

2.Turn the self-diagnosis device after ignition is ON.

3.Check the operation of the pre-charge relay with the KDS.(Actuation test → Battery Management System (BMS) → Main relay ( - ) ON & pre-charge relay ON)

   

Refer to the KDS screen for operating conditions and details.

4.Measure the voltage between the high voltage battery system connector positive ( + ) terminal and the negative ( - ) terminal.

Specification (V) : 0 or above

5.If the measured voltage is normal, perform the main relay working test.

6.If the measured voltage is abnormal, replace the Power Relay Assembly (PRA).(Refer to Power Relay Assembly (PRA) - "Removal and Installation")

Main Relay Working Test

1.Shut off the high voltage circuit.(Refer to Battery Control System (Standard) - “High Voltage Shut-off Procedure”)

2.Turn the self-diagnosis device after ignition is ON.

3.Check the operation of the main relay with the KDS.

(1)(Actuation test → Battery Management System (BMS) → Main relay ( - ) ON)

(2)(Actuation test → Battery Management System (BMS) → Main relay ( + ) ON)

   

Refer to the KDS screen for operating conditions and details.

4.Measure the voltage between the high voltage battery system connector positive ( + ) terminal and the negative ( - ) terminal.

Specification (V) : 0

5.If the measured voltage is normal, inspect the high voltage parts and A/C compressor.

6.If the measured voltage is abnormal, replace the Power Relay Assembly (PRA).(Refer to Power Relay Assembly (PRA) - "Removal and Installation")

Removal

   

• When working on high voltage system, the work should be performed by technicians who have completed the relevant training. A lack of understanding of the high voltage system can lead to serious accidents due to electric shock or electric leakage.

• When working on high voltage system or related components, make sure that you are familiar and comply with the "Safety Precautions, Cautions and Warnings." If you do not comply with the instructions, serious accidents due to electric shock or leakage may occur.

• When working on high voltage system, make sure to check the Personal Protective Equipment (PPE) and high voltage shut-off procedures.

1.Remove the Battery System Assembly (BSA) upper case.(Refer to High Voltage Battery System - "Case")

2.Disconnect the connectors (A, B, C, D, E).

3.Separate the wiring (A).

4.Separate the junction box cable (A) after removing the nuts.

Tightening torque :7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

5.Remove the inverter bus bar (A) after removing the bolts & nut and separating the fasteners.

Tightening torque :7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

6.Remove the bus bar (A) after removing the bolt and nut.

Tightening torque :7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

7.Remove the bus bar (A).

Tightening torque :7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

8.Disconnect the Integrated Charging Control Unit (ICCU) cable (A) after removing the nut.

Tightening torque :7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

9.Remove the Power Relay Assembly (PRA) (A) after removing the nuts.

Tightening torque :7.8 - 11.8 N·m (0.8 - 1.2 kgf·m, 5.8 - 8.7 lb·ft)

Installation

   

• When working on high voltage system, the work should be performed by technicians who have completed the relevant training. A lack of understanding of the high voltage system can lead to serious accidents due to electric shock or electric leakage.

• When working on high voltage system or related components, make sure that you are familiar and comply with the "Safety Precautions, Cautions and Warnings." If you do not comply with the instructions, serious accidents due to electric shock or leakage may occur.

• When working on high voltage system, make sure to check the Personal Protective Equipment (PPE) and high voltage shut-off procedures.

1.Install in the reverse order of removal.

   

• Install the Power Relay Assembly (PRA) to the specified torque.

• If the PRA is dropped, it may cause internal damage. (Do not reuse)

2.Perform the High Voltage Battery Pack Connector Check with the KDS before installing the Battery System Assembly (BSA) upper case.(S/W Management → Battery Management System (BMS) → High Voltage Battery Pack Connector Check)

   

Refer to the KDS screen for operating conditions and details.

Inspection

   

• When working on high voltage system, the work should be performed by technicians who have completed the relevant training. A lack of understanding of the high voltage system can lead to serious accidents due to electric shock or electric leakage.

• When working on high voltage system or related components, make sure that you are familiar and comply with the "Safety Precautions, Cautions and Warnings." If you do not comply with the instructions, serious accidents due to electric shock or leakage may occur.

• When working on high voltage system, make sure to check the Personal Protective Equipment (PPE) and high voltage shut-off procedures.

   

• Power Relay Assembly (PRA) can't be partially repaired, replacing PRA if necessary.

• The PRA must not be reused when disassembling it. (It must not be reused as tightening conditions of bolts and nuts are the main cause of the heat generation, which may cause overheating of PRA and fire)

• When inspecting the pre charge resistor, check without loosening the internal bolts and nuts.

• When inspecting PRA, it is efficient to check the relay after checking the pre charge resistor. (If the pre charge resistor is damaged, it is difficult to check the pre charge relay in PRA)

Power Relay Assembly (PRA) Inspection

1.Inspect the PRA.(Refer to Power Relay Assembly (PRA) - "On Vehicle Inspection")

Pre Charge Resistor Inspection

1.Remove the Power Relay Assembly (PRA).(Refer to Power Relay Assembly (PRA) - "Removal and Installation")

2.Measure the pre charge resistor.

Specification (Ω) : 55

Pre Charge Relay Inspection

1.Remove the Power Relay Assembly (PRA).(Refer to Power Relay Assembly (PRA) - "Removal and Installation")

2.Inspect the pre charge relay.

(1)Using a digital tester, measure the resistance between the battery ( + ) terminal and the inverter ( + ) terminal to check the weld condition.

Specification (Ω) : 55

(2)Using a digital tester, measure the resistance between the battery ( + ) terminal and the inverter ( + ) terminal to check the weld condition.

Item	Specification
Pre charge relay 12 V ON (Ω)	50 - 60
Pre charge relay 12 V OFF (Ω)	∞

Main Relay Inspection

1.Remove the Power Relay Assembly (PRA).(Refer to Power Relay Assembly (PRA) - "Removal and Installation")

2.Inspect the main relay.

Item	Relay OFF	Relay ON
Main relay ( + )
Main relay ( - )
Specification (Ω)	∞	Below 1