Installation Method and Precautions for 12V 90A Generator

I. Pre-installation Preparation

1. Tool Preparation

• Mechanical tools: Wrenches (matching the specifications of the generator fixing bolts), socket sets, torque wrenches, belt tensioner tools, screwdrivers (Phillips/flathead).

• Electrical tools: Multimeters, insulating tape, wire lugs, crimping pliers, waterproof heat shrinkable tubes.

• Auxiliary materials: New generator fixing gaskets, lock nuts, adaptive drive belts (replace if the original belt is aged), rust inhibitor.

2. Safety and Inspection

• Disconnect the negative terminal of the vehicle/equipment battery to prevent short circuits that may burn electrical appliances during wiring.

• Inspect the new generator: Confirm the model is 12V 90A, with no external damage, intact wiring terminals, and a rotor that rotates flexibly without jamming or abnormal noise.

• Inspect the installation position: Clean oil stains and rust on the generator fixing bracket, confirm the bracket is free of deformation, and ensure the surface of the drive pulley (engine crankshaft pulley/generator pulley) has no wear or cracks.

• Compatibility verification: Ensure the generator's mounting hole spacing and drive pulley specifications are compatible with the original equipment (such as vehicles, agricultural machinery). A 90A current requires a matching battery (12V 60Ah or above is recommended) and wires (wire diameter not less than 4mm²) to avoid line overload.

II. Core Installation Steps

1. Mechanical Fixing: Positioning and Fastening

• Remove the old generator (if replacing): Loosen the drive belt tensioner and remove the old belt; unscrew the fixing bolts of the old generator (usually 2-3, including adjusting bracket bolts), disconnect the wiring connector, and remove the old generator.

• Install the new generator: Place the new generator on the mounting bracket, align it with the fixing holes, insert the bolts without fully tightening to reserve adjustment space; if there is a grounding terminal, first reliably connect the grounding wire (or generator housing) to the equipment body (to ensure good grounding and reduce electromagnetic interference).

• Tighten the fixing bolts: Use a torque wrench to tighten the bolts according to the torque specified in the equipment manual (generally 20-30N・m, subject to specific equipment parameters) to avoid generator damage caused by vibration from loose bolts.

2. Transmission System: Belt Installation and Tensioning

• Install the drive belt: According to the equipment's belt routing diagram (usually affixed to the engine compartment or equipment housing), fit the new belt over the generator pulley, crankshaft pulley, idler pulley and other components.

• Adjust the belt tension: Use a tensioner tool to adjust the generator's adjusting bracket so that the belt tension meets the standard: when pressing the middle of the belt by hand, the sag should be approximately 10-15mm. An excessively loose belt is prone to slipping and overheating, while an excessively tight belt will accelerate bearing wear.

• Inspect the transmission status: Rotate the generator pulley to confirm the belt has no deviation or jamming, and all pulley systems rotate smoothly.

3. Circuit Wiring: Precise Matching (Key Step)

• B+ (Output Terminal): The main current output terminal of the generator, connected to the positive terminal of the battery.

• Operation: Select copper core wires with a diameter of ≥4mm², crimp wire lugs at both ends, fix one end to the B+ terminal and tighten the nut, and connect the other end to the positive terminal of the battery (it is recommended to connect a fuse holder in series with an 80-100A fuse to avoid overload and short circuit); the wires should be fixed firmly, kept away from high-temperature components (such as exhaust pipes), and the joints should be wrapped with waterproof heat shrinkable tubes for moisture and rust prevention.

• F (Field Terminal): Connected to the voltage regulator (some generators have built-in regulators, and this terminal may be omitted or connected to the ignition switch).

• Operation: For external regulators, connect the F terminal to the corresponding terminal of the regulator; for internal regulators, the F terminal is usually connected to the positive terminal of the battery through the ignition switch (power is supplied when the key is turned to the "ON" position to activate the generator excitation).

• N (Neutral Terminal): Outputs approximately 6V voltage, mostly used to control the charging indicator light or other auxiliary equipment. If not needed, it can be left unused (the terminal should be wrapped with insulating tape to prevent short circuits).

• IG (Ignition Terminal): The excitation control terminal of some generators with built-in regulators, connected to the output terminal of the ignition switch. It supplies power to the regulator when the key is turned on.

4. Charging Indicator Light Wiring (if applicable)

III. Post-installation Commissioning and Inspection

1. Initial Power-on Inspection

• Connect the negative terminal of the battery, turn on the equipment power (turn the key to the "ON" position), and observe whether the charging indicator light is on (normal state).

• Start the engine/power source and maintain the rotational speed at 1500-2000rpm. At this time, the charging indicator light should go out; use a multimeter to measure the voltage at both ends of the battery. The normal charging voltage is 13.8-14.5V (standard for 12V systems). If the voltage is too low (<13V) or too high (>15V), it indicates a wiring error or generator fault.

2. Load Test

• Turn on the electrical loads of the equipment (such as vehicle lights, air conditioners, etc.), continuously measure the battery voltage, which should still remain within the range of 13.5-14.2V. If the generator has no abnormal noise or overheating, it indicates stable output.

3. Mechanical Status Re-inspection

• Stop the machine after running for 10-15 minutes, check whether the generator fixing bolts are loose, whether the belt has slipping marks, whether the bearing has abnormal noise, and whether the shell temperature is within a reasonable range (not scalding to the touch).

IV. Precautions

• Polarity must never be reversed: The B+ terminal must be connected to the positive terminal of the battery. Reversing the polarity will burn the generator rectifier, regulator and equipment electrical appliances, and may even cause a fire.

• Avoid no-load operation: After starting the generator, connect the load (or battery) as soon as possible. Long-term no-load operation may cause the output voltage to rise excessively, damaging internal components.

• Regulator matching: A 90A high-power generator must be paired with a suitable regulator (built-in or external); otherwise, the output voltage cannot be stabilized, which is likely to damage the battery and electrical equipment.

• High-temperature protection: Keep the generator away from high-temperature components such as exhaust pipes and cylinder blocks, and protect wires with heat-resistant sleeves to prevent insulation layer melting and short circuits.

• Regular maintenance: After installation, regularly check the belt tension, wiring joints and battery status to avoid charging faults caused by looseness or aging.

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