AITO M7 High-Voltage System Safe Operation Guide

Fault Background

The AITO M7's high-voltage system covers the drive motor, drive motor controller, high-voltage battery pack, AC/DC combo charge port, on-board charger (OBC), air conditioning compressor, and heater (PTC), with power distribution handled by the high-voltage junction box (integrated with the DC-DC converter) and the high-voltage power distribution unit (PDU) — the PDU clearly arranges interlock input, interlock output, and two sets of relay control (+/-), and the high-voltage system and high-voltage interlock system are laid out according to 2WD/4WD configurations. The manual's safety framework is very complete: orange-yellow warning labels + orange high-voltage cables are the visual identifiers for high-voltage components and are strictly prohibited from being touched; repairs must be equipped with insulating protective gear (insulating mat, protective goggles, insulating gloves) and insulating tools (insulating mat, insulating tools, traction battery installation plug, traction battery workbench, insulating hook); the work area must have high-voltage warning signs, high-pressure water gun and plenty of water, warning tape, dedicated service bay, and grounding; personnel must hold the 《Special Operation Permit (Electrician)》+《Junior (or above) Electrician Certificate》 and have a dedicated supervisor; after powering down the high-voltage system (disconnecting the service disconnect switch), must wait for full discharge. This article organizes these checklists and disassembly/assembly points into a reference guide.

High-Voltage Components and Identification

• The high-voltage junction box is integrated with the DC-DC converter (high-voltage box assembly), and its connectors include electric A/C compressor connector and other integrated connectors.
• PDU connector definitions: interlock input, interlock output, relay control +/− (two sets).
• The high-voltage system and high-voltage interlock system are arranged according to 2WD / 4WD configurations.

Safe Operation Checklist (as per manual)

Insulating protective gear: insulating mat, protective goggles, insulating gloves.

Insulating tools: insulating mat, insulating tools, traction battery installation plug, traction battery workbench, insulating hook.

Work area equipment: high-voltage warning signs, high-pressure water gun and plenty of water, warning tape, dedicated service bay, and grounding.

Personnel requirements:

• Service personnel must wear insulating protective equipment before operation; inspect for no damage/holes/cracks before use, inner and outer surfaces clean and dry, do not operate with water.
• A dedicated supervisor must be assigned; both the supervisor and service personnel must hold the nationally recognized 《Special Operation Permit (Electrician)》 and 《Junior (or above) Electrician Certificate》.
• Personnel without high-voltage training are prohibited from performing high-voltage component repairs.

Power-down discipline: Disconnect the battery negative terminal → wear insulating protective gear to power down the high-voltage system (disconnect the service disconnect switch) → wait for full discharge (components with internal capacitors such as motor controller, charger, etc.) → other high-voltage components are strictly prohibited from arbitrary disassembly and repair.

Charging Socket and Thermal Management

AC/DC combo charge port assembly: The insulation resistance between AC charging socket L, N and ground must be tested as specified; insulation tests for all high-voltage components must be performed as specified to avoid damage to components and vehicle due to misoperation; if connectors are dirty or wet, wipe with a dry clean cloth; do not charge if damaged or corroded.

Thermal management controller assembly (3109): The integrated thermal management module is fixed to the front crossmember (left), and the thermal management module and coolant pipe mounting bracket are fixed per the manual torque specifications.

Safety Warnings

• This article is for technical reference only. High-voltage system repairs must be performed by qualified technicians holding both certificates (Special Operation Permit (Electrician) + Junior or above Electrician Certificate) under the supervision of a dedicated supervisor, following OEM specifications. Readers unfamiliar with these procedures are strictly prohibited from performing operations themselves.
• High-voltage components (orange-yellow labels) and orange high-voltage cables are strictly prohibited from being touched; do not touch exposed or damaged cables.
• After powering down the high-voltage system (disconnecting the service disconnect switch), you must wait for full discharge; it is strictly prohibited to disassemble high-voltage components before discharge is complete.
• Insulating protective gear must be inspected for integrity, cleanliness, and dryness before use; do not operate with water.
• The work area must be equipped with high-voltage warning signs, warning tape, dedicated bay, grounding, and a high-pressure water gun with plenty of water (for emergency use).

Maintenance Insights

The AITO M7 manual's safety system is a textbook framework of "checklist + dual certificates + supervision". Checklist: five protective gear items, five tool items, and six work area items are all specified — special items like the traction battery installation plug, traction battery workbench, and insulating hook are often missing in many repair shops, but the manual includes them directly in the required list; the high-pressure water gun and plenty of water are emergency flushing equipment, and this detail shows the manual treats "just in case" as standard. Dual certificates + supervision: Special Operation Permit (Electrician) + Junior or above Electrician Certificate, plus a dedicated supervisor — personnel requirements are specified down to certificate names. On-site execution, remember three things: orange-yellow labels and orange cables are "no-touch lines" (including connectors); wait for discharge after power-down (capacitive components still discharge after the service disconnect switch is opened; rushing equals live work); perform insulation tests as specified (charge socket L/N to ground insulation resistance; misoperation can damage components). Structurally, remember: high-voltage junction box integrated with DC-DC converter, PDU with interlock input/output and two sets of relay control, and 2WD/4WD two high-voltage configurations.

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【This article is for reference only】