The core of determining the safety redundancy of an electric forklift lies in evaluating its "protective capability that exceeds basic safety standards"—specifically, whether the equipment can reduce accident risks through design redundancy under sudden failures (such as brake failure, sudden power drop), improper operations (such as overloading, sharp turns), and harsh working conditions (such as ramps, slippery surfaces). Below are 6 practical methods for assessment, covering four key dimensions: "structural design, functional configuration, performance redundancy, and compliance."
I. Check "Structural Safety Redundancy": Examine the "Reinforced Design" of Key Components
The foundation of safety redundancy is "structural strength that exceeds conventional load requirements." Focus on observing the hardware design related to load-bearing and protection:
1. "Strength Redundancy" of Load-Bearing Structures
Forks and Mast
- Check "Material and Specifications": Forks of regular forklifts must be marked with "material grade (e.g., 45# steel, Q345B)" and "safety factor" (safety factor ≥ 1.5; for example, a fork with a rated load of 3 tons can actually withstand an impact load of over 4.5 tons). Forks from small manufacturers have no markings, and their materials are mostly ordinary carbon steel (safety factor ≤ 1.2, prone to bending when overloaded).
- Examine "Reinforcement Design": Check if the mast columns have "double-layer steel plates" or "reinforcing ribs" (masts of forklifts with a load capacity of over 3 tons require at least 2 reinforcing ribs). Also, check if there is a "triangular support plate" at the connection between the fork root and the mast (to distribute loads and avoid fracture due to stress concentration).
Chassis and Counterweight
- The main load-bearing beam of the chassis must be "integrally formed steel" (not spliced), with a thickness 10%-20% greater than the basic standard for the same load class (e.g., the basic thickness of a 3-ton forklift chassis is 8mm, while high-redundancy models reach 9-10mm).
- The weight of the counterweight must be 5%-10% greater than the "theoretical balance weight" (e.g., the theoretical counterweight of a 3-ton forklift is 800kg, while high-redundancy models reach 840-880kg to prevent forward tipping under heavy loads).
2. "Redundant Design" of Protective Structures
Cab Protection
If a cab is equipped, check the "rollover protective structure (ROPS)" and "front guard plate":
- The ROPS must withstand a vertical load of "1.5 times the forklift’s own weight" (e.g., a 3-ton forklift weighs 4 tons, so the ROPS can withstand 6 tons of pressure to avoid deformation when heavy objects fall).
- The thickness of the front guard plate must be ≥ 3mm (to prevent the cab from being hit by goods).
Motor/Controller Protection
The housing must be made of "cast aluminum" (not plastic) with a protection rating of ≥ IPX4 (splash-proof). Additionally, there must be "cushion pads" inside (to prevent component loosening and short circuits caused by vibration).
II. Test "Functional Safety Redundancy": Evaluate "Dual Protection" for Emergency Situations
The core of safety redundancy is "having a backup function to rely on when a single component fails," which needs to be verified through operation:
1. Braking System: Dual Braking Redundancy
Test Method 1: Power-Off Braking
While the forklift is moving (at a speed of 5km/h), suddenly cut off the main power (by pressing the emergency power-off switch) and observe if it stops immediately (qualified standard: braking distance ≤ 2 meters). If the forklift continues to slide after power-off, it indicates a lack of "power-off braking redundancy" (relying only on hydraulic brakes, which fail after power-off).
Test Method 2: Ramp Braking
Park the fully loaded forklift (at rated load) on a 15° ramp, pull the handbrake, release the foot brake, and observe if it rolls (qualified standard: no rolling after 5 minutes of standing). Then, simulate an extreme situation where "both the handbrake and foot brake fail" and check if there is a "ramp parking lock" (equipped on some high-redundancy forklifts to mechanically lock the wheels).
2. Lifting System: Anti-Fall Redundancy
Test Method 1: Load Retention
Raise the fully loaded forks to a height of 3 meters, turn off the hydraulic pump (shut down or cut off power), keep it for 10 minutes, and observe the fork settlement (qualified standard: settlement ≤ 3mm; ordinary forklifts allow ≤ 5mm). The smaller the settlement, the better the dual-sealing redundancy of the hydraulic valve’s "check valve + relief valve" (if one seal fails, the other can still maintain pressure).
Test Method 2: Emergency Lowering
Simulate a hydraulic system failure (ask the manufacturer to disconnect the main hydraulic pipe and keep only the emergency pipe), operate the "emergency lowering lever," and observe if the forks lower at a constant speed (speed ≤ 0.3m/s). Forklifts without an emergency lowering function cannot be rescued if the forks get stuck, posing safety risks.
3. Electrical System: Anti-Overload/Short-Circuit Redundancy
Check Protection Devices
Open the electrical box and confirm the presence of "dual protection":
- The main circuit has a "circuit breaker" (trips when overloaded).
- Branch circuits (motor, lights) have "fuses" (blows when short-circuited).Ensure the parameters of the two match (e.g., a 15kW motor is equipped with a 30A circuit breaker + 25A fuse to avoid protection failure).
Test Overload Protection
Make the fully loaded forklift climb a slope at low speed for a long time (5 minutes) to simulate an overload condition. Observe if it "automatically reduces speed or shuts down" (high-redundancy forklifts have an "overload protection algorithm," while ordinary forklifts may directly burn the motor).
III. Verify "Performance Safety Redundancy": Check the "Reserved Margin" of Parameters
Safety redundancy is also reflected in "actual performance exceeding nominal parameters," avoiding the risk of "full load being the limit":
1. Power Performance Redundancy
Compare "nominal power" with "actual demand": The rated power of the motor must be at least 20% higher than the "maximum power required for full-load operation" (e.g., a 3-ton forklift requires 12kW of power when climbing a slope with a full load, so the motor’s rated power should be ≥ 14.4kW). This can be verified through the "power curve" provided by the manufacturer or on-site testing: when climbing a 15° slope with a full load, the value displayed on the motor power meter should be ≤ 80% of the rated power (reserving 20% redundancy).
2. Battery Life Redundancy
Verify "nominal battery life" with "actual battery life": The "full-load battery life" nominal by the manufacturer must be at least 30% longer than the "daily actual operating hours" (e.g., if 8 hours of battery life are needed per day, the nominal battery life should be ≥ 10.4 hours). On-site testing: When the forklift runs continuously at a full load at 5km/h, the power consumption per hour should be ≤ 10% (so 100% power is consumed in 10 hours, meeting redundancy requirements). If the power consumption per hour is 15%, there is no redundancy (nominal battery life is exaggerated).
IV. Review "Compliance and Certification": The "Bottom-Line Guarantee" for Safety Redundancy
Formal certifications are the foundation of safety redundancy. Confirm two types of key certifications:
National Mandatory Certification
The forklift must pass the certification of Safety Specification for Powered Industrial Trucks (GB/T 10827-2014) and have a "special equipment manufacturing license number (TS certification)" on the nameplate. Forklifts without this certification fail to meet safety design standards (e.g., no overload protection, no braking redundancy) and are illegally produced.
Industry-Specific Additional Certifications
For special scenarios (e.g., explosion-proof, cold chain), additional corresponding certifications are required:
- Explosion-Proof Scenarios: Must comply with Powered Industrial Trucks for Explosive Atmospheres (GB/T 26562-2011) with a certification level of ≥ EX IIB T4 (spark-proof, high-temperature resistant).
- Cold Chain Scenarios: Must have a "low-temperature adaptability certification" (safety functions work normally at -30℃~0℃, with no component failure due to freezing).
V. Inquire About "User Cases": "Redundancy Verification" in Actual Working Conditions
The authenticity of safety redundancy can be verified through "long-term usage feedback from users in the same industry":Request "customer cases in the same industry" from the manufacturer (e.g., if you work in logistics warehousing, prioritize inquiring about the usage of other warehousing enterprises). Focus on understanding:
- Whether failures such as "full-load emergency brake failure," "ramp rolling," or "sudden fork settlement" have occurred (no such failures indicate effective redundancy design).
- Performance under extreme conditions (e.g., outdoor operation in heavy rain, whether the motor short-circuits due to insufficient waterproof redundancy).
Conclusion: The "Core Logic" for Determining Safety Redundancy
The essence of safety redundancy is "a 'backup' in design"—it does not focus on "how well it performs under normal conditions" but on "how safe it is under extreme conditions." When making a judgment, follow the "three priorities" principle:
- Prioritize forklifts with "dual protection functions" (e.g., dual braking, dual hydraulic sealing).
- Prioritize forklifts with "structural strength exceeding standards" (e.g., thickened chassis, heavier counterweight).
- Prioritize forklifts with "multiple certifications + mature cases" (to avoid the risk of "unverified new designs").
Through the above methods, you can effectively identify whether an
electric forklift has the "ability to respond to sudden risks" and prevent operational accidents caused by "insufficient safety redundancy."
