Installation Methods and Precautions for 24V 50A Hitachi/Isuzu Generators

I. Pre-Installation Preparation (Core Prerequisites)

Tool and Accessory Inspection

Essential Tools:

• Socket wrench (matching the generator fixing bolts)

• Torque wrench (to ensure the bolt tightening torque meets requirements)

• Wire stripper, crimping tool, insulating tape

• Multimeter (for testing circuit continuity/insulation)

• Level (for calibrating the installation plane)

Essential Accessories:

• Original fixing bracket (or compatible shock-absorbing bracket to reduce operational vibration)

• Specifications-compliant wires (for 24V 50A systems: main power wire cross-section ≥10mm² copper core; control wire cross-section ≥1.5mm²)

• Copper wiring terminals (with anti-oxidation treatment)

• Grounding bolt

• Exhaust muffler (for fuel-powered generators)

• Cooling system accessories (water pipes/coolant for water-cooled models; wind deflector for air-cooled models)

Equipment Inspection:

• Confirm the generator has no external damage, no oxidation on wiring terminals, and no jamming of the rotor/stator.

• Check that fluid levels (engine oil, fuel) meet requirements (for fuel-powered generators, fill with the specified grade of diesel/gasoline as per the manual).

Installation Environment Requirements

Ventilation:

• Reserve ≥30cm of heat dissipation space around the installation location; avoid confined spaces (to prevent overheating due to high temperature).

• For indoor installation, install an exhaust fan (air volume ≥1.2 times the generator's heat dissipation requirement).

Load-Bearing Capacity:

• The load-bearing capacity of the installation plane (floor/bracket) must be ≥1.5 times the generator's weight (24V 50A fuel-powered generators weigh approximately 20-30kg; confirm the specific model weight). This prevents foundation deformation caused by long-term vibration.

Protection:

• Keep away from moisture (relative humidity ≤85%, no condensation), dust (to avoid internal insulation degradation), and corrosive gases (e.g., acid-base environments).

• For outdoor installation, install a rain shelter (without blocking heat dissipation vents).

II. General Installation Procedures (Mechanical/Electrical Sections)

(A) Mechanical Installation: Fixing and Auxiliary System Connection

Generator Fixing

1. Place the generator: Use a level to calibrate the installation plane, ensuring the generator is horizontal (inclination ≤1° to avoid fluid leakage or poor lubrication).

2. Install the shock-absorbing bracket: If equipped with original shock-absorbing pads/brackets, fix them between the generator base and the installation plane. Align the bracket with the generator's bolt holes (use 8.8-grade high-strength steel bolts; refer to the manual for tightening torque, generally 25-35N·m).

3. Secure the generator: Pass bolts through the generator's fixing holes and the installation base (e.g., angle steel brackets, floor embedded plates). Tighten gradually in a diagonal pattern to avoid casing deformation from uneven force.

Cooling System Installation (By Model Type)

Water-Cooled Models:

• Connect inlet/outlet water pipes: Use high-temperature resistant rubber hoses (temperature resistance ≥120℃) to connect the generator's water-cooling interfaces to the radiator. Secure with pipe clamps (to prevent water leakage). Fill with the manufacturer-recommended coolant (e.g., ethylene glycol-based, freezing point ≤-30℃) to the tank scale line. Open the air release valve to expel air, then close it.

(B) Electrical Installation: Wiring and Grounding (Core Risk Point – Perform with Power Off)

Pre-Wiring Preparation

1. Disconnect all relevant power sources (e.g., vehicle power supply, battery negative terminal). Use a multimeter to test the insulation resistance of the generator's wiring terminals (stator winding to ground ≥50MΩ; rotor winding to ground ≥10MΩ. Dry the generator if the resistance is below standard).

2. Wire preparation: Strip 5-8mm of insulation from the wire ends (without damaging the copper core). Crimp the wiring terminals and wrap with insulating tape (or heat-shrink tubing) to avoid exposure.

III. Key Precautions (Core of Safety and Reliability)

1. Safety Operation Taboos

• It is strictly prohibited to wire with power on: Disconnect all relevant power sources during installation. After wiring, use a multimeter to confirm no short circuit between positive and negative terminals (main circuit resistance ≥100Ω) before powering on for testing.

• Avoid unauthorized modifications: Do not alter the generator winding or wiring terminal specifications (e.g., using thin wires instead of thick ones) or remove protective components (e.g., fuses, insulation covers).

• Special precautions for fuel-powered generators:

• Turn off the generator before refueling; avoid fuel spills (wipe up spills with a dry cloth and keep away from open flames).

• Do not open the fuel or oil filler caps during operation (prevents scalding from splashing fluids).

2. Installation Specification Requirements

• Strictly follow the original manual: Installation details (e.g., bolt torque, wiring pins) may vary significantly between models (e.g., Hitachi LR180-700, Isuzu 8-97250-240-0). The manual takes precedence over general procedures. Contact the brand's after-sales service if the manual is missing.

• Wire routing requirements: Route main power wires and control wires separately (spacing ≥10cm). Secure wires to brackets to avoid insulation damage from vibration. Maintain a bending radius ≥5 times the wire diameter (prevents wire breakage).

• Sealing and protection: Seal wiring terminals, water pipe interfaces, and exhaust interfaces (using sealant or gaskets) to prevent water and dust ingress. For outdoor installation, install a waterproof cover for the generator's junction box.

IV. Special Reminder

References：

Sources of Technical Information

I. National Standards and Industry Specifications (Core Basis)

• GB/T 15548-2023 "General Technical Conditions for Three-Phase Synchronous Generators Driven by Reciprocating Internal Combustion Engines"

  Specifies the voltage regulation accuracy (±5%) and current output stability requirements for 24V systems.

• QC/T 425-1999 "Mounting Dimensions for Automotive DC Generators"

  Defines mechanical installation dimension standards such as generator fixing hole spacing and shaft diameter.

• JB/T 6700-2007 "Mounting Dimensions for Alternators Used in Motor Vehicles and Internal Combustion Engines"

  Prescribes generator bracket installation positions and tightening torque (generally 25-35N·m).

• ISO 7651:1991 "Mounting Dimensions for Alternators for Commercial Vehicles and Buses"

  An international standard applicable to mechanical interface specifications of various 24V 50A generators.

• GB 50194-2014 "Safety Code for Power Supply and Use at Construction Sites"

  A mandatory standard specifying grounding resistance (≤4Ω) and electrical safety distance requirements.

• GB/T 21428-2008 "Safety of Generator Sets Driven by Reciprocating Internal Combustion Engines"

  Details requirements for generator safety protection, grounding, and insulation.

II. Original Technical Manuals of Hitachi/Isuzu (Most Authoritative Sources)

• Hitachi Generator Official Installation Manual (e.g., RAF50NH4 Series)

  Clarifies wiring terminal definitions (B+, F, E/N) and precise torque values (B+ terminal: 8-12N·m).

  Provides cooling system connection methods and shock-absorbing bracket installation requirements.

• Isuzu Generator Technical Specification Sheet (e.g., Model 8-98092116-0)

  Specifies the basic three-wire connection: B+→Battery/Switch, F→Regulator, E→Ground.

  Details that four-pin models require additional connection of the neutral wire (N) to the instrument indicator light.

III. Industry Technical Guides and Practical Experience

• Professional Installation Manual for Automotive Generators

  Recommends using ≥10mm² copper core wires for main power and ≥1.5mm² copper core wires for control signals.

  Emphasizes that the main circuit must be equipped with a 55-60A fuse, installed near the generator's "+" terminal.

• Electrical System Standards for Construction Machinery

  Requires the voltage drop of wires between the generator and battery to be ≤0.5V to ensure charging efficiency.

• Installation Specifications for Diesel Generator Sets

  Prescribes a ventilation space of ≥30cm and a heat dissipation distance of ≥1m to avoid high-temperature overload.

IV. Sources of Key Technical Details

Electrical Safety Requirements:

• Prohibition of live wiring: Derived from mandatory clauses in GB 50194-2014 and GB/T 21428-2008.

• Grounding requirements: Originates from Clause 4.0.2 of GB 50194-2014 and GB 50057-2010 "Code for Design of Protection of Structures Against Lightning".

Mechanical Installation Specifications:

• Levelness ≤1°: Referenced from installation accuracy requirements in ISO 7651 and JB/T 6700.

• Shock-absorbing brackets: Based on anti-vibration design standards in Hitachi and Isuzu's original manuals.

Commissioning Standards:

• No-load voltage 27-28V: Complies with the 24V system charging voltage standard (1.125 times the rated voltage).

• Load regulation rate ≤±5%: Derived from technical indicators in GB/T 15548-2023.