• Jun 04, 2025
• Case Studies

7 Ton NR Hoist Deployment for Crane Rental Company in Brazil

Discover how a 7-ton NR hoist transformed crane rentals in Brazil! Learn about its deployment, benefits, and how it boosts efficiency for your projects.

In Brazil, the crane rental industry supports diverse sectors such as construction, manufacturing, and logistics. Rental companies must supply reliable lifting equipment to clients with varying needs. The customer operates a crane rental company headquartered in São Paulo, with branch offices in Rio de Janeiro and Belo Horizonte. The firm supplies lifting equipment—cranes, hoists, and accessories—to contractors, factories, and event organizers. As Brazil's infrastructure spending and manufacturing outputs grew, so did demand for rental cranes and hoists.

Operational Requirements

Rental clients ranged from small workshop owners requiring occasional lifts to large construction firms needing extended hoist usage on major projects. Key requirements included:

• Rated Capacity: Ability to lift 7 tonnes as a standard offering, covering common mid‐range loads (e.g., machinery parts, structural steel sections). This capacity fit between the company's existing 5 t and 10 t hoists, reducing tandem lift needs.
• Duty Cycle and Reliability: Equipment had to withstand frequent start‐stop cycles. Operational demands ranged from 8 to 12 hours daily. Duty classification M5–M6 (moderately heavy to heavy) was essential to avoid early wear and unplanned downtime.
• Ease of Installation and Adjustment: Rental teams needed to set up hoists quickly on various crane types—single‐girder cranes, gantry cranes, and temporary monorail systems on construction sites. Adjustability of hook height (6 m–24 m) and simple rail alignment procedures were critical.
• Safety Compliance: Brazilian regulations mandate overload protection, regular inspections, and fail‐safe braking systems on all electric hoists used in urban and industrial environments. Clients also requested anti‐collision features when hoists coexisted with other cranes on large sites.
• Service and Maintenance: Low maintenance intervals, readily available spare parts, and remote monitoring capabilities reduced rental downtime. The company's maintenance team sought predictive alerts to schedule servicing before failures occurred.

Challenges before Using the NR Hoist

Equipment Limitations

Prior to NR hoist adoption, the rental company relied on third‐party electric hoists sourced from various manufacturers. These hoists included 5 t and 10 t models, but no 7 t option. When clients needed to lift loads between 6 t and 7 t, rentals required either two 5 t hoists in tandem or using a single 10 t hoist at reduced capacity. Tandem lifts often introduced alignment issues and safety concerns, while using a 10 t hoist on a 7 t load reduced available capacity for attachments.

Maintenance and Safety Issues

Hoists from different suppliers meant varied maintenance schedules. Some hoists required lubrication every 200 operating hours; others needed gearbox inspections every 150 hours. Lack of standardized components forced the maintenance team to stock diverse spare parts. In 2024 alone, unplanned hoist maintenance accounted for 18% of total downtime across the rental fleet. Clients reported 5 near‐miss incidents where hoist brake drift or worn rope guides caused loads to swing unexpectedly. According to industry data, electric hoist failures can cost rental operators up to US $250 per hour in lost billing plus repair costs.

Rental Client Demands

Clients handling infrastructure projects—bridge construction, water treatment plant retrofits—needed mid‐range hoists capable of frequent cycles. Workshops and small‐batch manufacturers sought hoists that could run 4,000–5,000 cycles yearly without downtime. With an annual installation count of 50–80 project sites, the rental company needed a hoist that combined 7 t capacity with high duty classification and minimal upkeep. Underperforming hoists led to client dissatisfaction, delays in project timelines, and occasional contract penalties for missed deadlines.

NR Hoist Product Design

NR Series Overview

The NR electric hoist series from Yuantai features a modular design, intelligent control, and multiple configurations to suit diverse crane systems. Main NR models include:

• NRL (Low‐Headroom Monorail Hoist): Built for minimal hook approach and low headroom scenarios. Ideal for workshops with vertical space constraints.
• NRS (Standard‐Headroom Monorail Hoist): Offers standard mounting height, suitable for most single‐girder cranes.
• NRT (Double‐Rail Trolley or Crab): Integrates a trolley system for double‐girder cranes, providing increased stability and higher hook heights.
• NRF (Foot‐Mounted Hoist): Designed for fixed installations on structural frames; used in gantry cranes and heavy‐duty lifting stations.

All NR hoists comply with FEM (European Federation of Materials Handling) standards, offering working duty classes from M5 to M7. Lifting speeds for 3 t–10 t models range from 5/0.8 m/min (fast/slow), while traveling speeds span 2–20 m/min. For a 7 t rated capacity, the NR's dual‐speed motor delivers precise lifting control, key to rental scenarios where varied load weights require lock‐step speed changes.

7 Ton NR Hoist Specifications

The 7 t NR model (custom variant between the standard 5 t and 10 t) provided the following core specifications:

These specifications ensured the 7 t NR hoist met mid‐range lifting demands while maintaining compatibility with existing crane rails and power systems. The dual‐speed motor configuration (fast/slow) allowed precise positioning, critical for rental clients with installation variances.

Advanced Features and Safety Systems

The 7 t NR hoist integrated the following advanced features:

• Modular Frame and Components: The hoist frame uses welded plates and rods with high‐strength bolts for easy disassembly. Core components (lift motor, gearbox, control box) share modular interfaces across the NR series, simplifying spare part management.
• Overload Protection: Built‐in load sensors detect if the lift exceeds 7 t. Upon overload, the system cuts power to the motor and engages the brake, preventing wire rope deformation and component damage.
• Anti‐Dropping Device: A mechanical latch engages if the brake fails. This device meets EN 13157 fall protection requirements, ensuring loads cannot inadvertently drop even if electrical faults occur.
• Limit Switches: Upper and lower limit switches automatically stop lifting or lowering before the hook collides with the upper frame or the rope completely unwinds, reducing mechanical stress and preventing accidents.
• VFD Control for Travel: The travel motor uses a frequency conversion drive to provide stepless speed control (0–15 m/min). Smooth acceleration/deceleration reduces shock loads during transit, extending gearbox life by an estimated 30% compared to fixed‐speed travel motors.
• Intelligent Monitoring System: An IoT module captures operational data (motor temperature, rope wear, running hours). Rental teams access real‐time performance metrics through a cloud platform, allowing proactive maintenance. This reduces unplanned breakdowns by up to 25% in analogous deployments.
• High‐Strength Wire Rope Drum: The drum features a flange plate bending structure, reducing rope slip and uneven spooling. Finite Element Analysis (FEA) during design ensured minimal deformation under full‐load conditions, maintaining rope integrity over 15,000 cycles.
• Clearance and Headroom: For NRL (low‐headroom) configuration, the hoist lowered the structural height by 150 mm compared to standard‐headroom models. This feature suits workshops and rental clients needing temporary crane lines in buildings with limited vertical space.

These features ensured the 7 t NR hoist offered rental clients a safe, high‐duty, and low‐maintenance solution. The modular design and remote monitoring were particularly valuable for a rental company managing fleets across multiple states.

Installation Process

The rental team followed these steps to install the 7 t NR hoist:

• Runway Bridge Assembly: Welded and bolted existing I‐beam sections to vertical supports rated at 12 t capacity. Precision‐machined end trucks were installed with wheel flange riles. Wheel alignment used a laser tracker to confirm a 2 mm vertical deviation tolerance over the span to minimize rail wear.
• Hoist Mounting: Hoist frame was craned onto the runway. For low‐headroom scenarios, the team chose the NRL configuration, reducing overall height by 150 mm. The structural bolts and flanges were torqued to manufacturer‐specified values (90 Nm for main frame, 50 Nm for motor mounts).
• Electrical Connections: A local electrician wired the hoist to a dedicated 400 V, 50 Hz, 3‐phase circuit with a 40 A circuit breaker and earth‐leakage protection. Control cables (5 m length) connected to a remote pendant station featuring an emergency stop, travel buttons, and lift controls. All wiring met Brazilian NBR 5410 standards.
• Safety System Calibration: Overload protection sensors were tested using calibrated test weights. Upper and lower limit switches were set to stop the hook at 24 m and 6 m, respectively. Anti‐dropping devices underwent manual pull tests to confirm mechanical latch engagement at ≤0.5 m/s descent speeds.

Across all three sites, each installation took no more than 8 hours from runway alignment to commissioning, thanks to modular components and detailed site preparation. This rapid deployment reduced the client's operational downtime by an average of 38% compared to previous hoist installations that took up to 16 hours.

Training and Commissioning

After installation, the team conducted a two‐day training program for client operators and the rental company's service staff. Training topics included:

• Hoist Operation: Safe use of the pendant control, load charts interpretation, and dual‐speed lifting procedures.
• Safety Protocols: Daily inspection routines (rope wear indicators, brake performance checks, visual inspection of sheaves) and monthly maintenance checkpoints (gearbox oil levels, motor winding temperature logging).
• Remote Monitoring Dashboard: Using the platform to view real‐time hoist parameters—current draw, running hours, rope cycles, and alert thresholds. Operators learned to set email notifications for abnormal readings (overheating, overload events).
• Troubleshooting: Basic fault codes (e.g., E01: overload, E02: brake malfunction, E03: limit switch failure) and corrective actions (resetting sensors, replacing fuse links, adjusting limit switch cams).

The customer test ran this 7 ton NR hoist and they had a very smooth operation. We made a return visit a month later and the customer informed us that everything was good with this hoist.

Advantages of NR Hoist for Crane Rental

Modular Design and Customization

The NR hoist's modular architecture enabled the rental company to tailor configurations readily. By selecting NRL or NRS variants, installations accommodated different headroom constraints. Spare parts such as lifting gear reducers (NGL series) and traveling gear reducers (NGT series) share cross‐compatibility across 3 t to 10 t models. This modularity drove down stocking costs. Rental technicians could swap components (for example, change a 5 t gearbox to a 7 t variant) within 2 hours, reducing hoist swap‐out time in field warehouses.

Energy Efficiency and Maintenance Benefits

VFD travel motors consumed up to 15% less power than fixed‐speed alternatives during moderate loads. Regenerative braking during deceleration returned 5–7 kWh per operational cycle to the facility grid at workshop installations. Over one year, this translated to US $800 in energy savings per hoist. The high‐efficiency gear motor (NMD series) reduced heat generation, extending lubrication intervals to every 1,000 hours (versus 500 hours on prior models). As a result, annual maintenance costs per hoist fell from US $2,500 to US $1,800.

Versatility Across Operational Environments

Clients rented the 7 t NR hoist for diverse tasks:

• Indoor Manufacturing Workshops: NRL low‐headroom configuration lifted heavy die cast molds (6.8 t) in assembly lines with limited ceiling clearance (5.5 m).
• Outdoor Construction Sites: NRT double‐rail trolley variants mounted on portable gantries lifted steel girders (7 t) under sunlight, dust, and rain. The IP54 motor protected against environmental ingress; IP65 upgrades ensured durability during intermittent rainfall.
• Logistics Yards: Clients used the hoist over open‐top shed rails to load/unload shipping containers. The overload protection and limit switches prevented damage to containers and yard infrastructure.

This adaptability improved the rental company's competitive edge—offering a single hoist model deployable across multiple rental scenarios without significant reconfiguration.

Additional Applications Beyond Crane Rental

Warehousing and Logistics

Electric wire rope hoists with capacities around 7 t serve critical roles in modern warehouses handling heavy pallets, steel coils, and machinery components. They can mount on existing racking systems or portable beams for cross‐docking operations. According to logistics industry reports, automated wire rope hoists reduce material handling time by 25% and increase throughput by 18% when integrated with conveyor systems.

Manufacturing and Assembly

In automotive and heavy equipment manufacturing plants, a 7 t hoist lifts engine blocks, transmission assemblies, and chassis sections. The M6 duty classification suits high‐cycle applications—up to 10,000 lifts annually. For precision assembly lines, dual‐speed lifting (6/1 m/min) allows workers to position parts within ±20 mm accuracy.

Construction and Infrastructure Projects

Beyond rental contexts, general contractors use 7 t hoists for erecting steel frameworks, lifting formwork, and positioning concrete molds. Their compatibility with gantry systems and scaffolding cranes supports façade panel installation on high‐rise buildings. For highway bridge construction, hoists temporarily lift girders and rebar cages from ground cranes onto form systems. The overload protection and anti‐dropping devices ensure compliance with Brazil's NR 18 safety standards for construction equipment.

Other Industrial Applications

Additional use cases include:

• Power Generation Facilities: In thermal and hydroelectric plants, 7 t hoists lift generator rotors, turbine blades, and heat exchangers during installation or maintenance.
• Petrochemical Plants: Explosion‐proof variants of NR hoists handle heavy valves and heat exchangers in potentially flammable atmospheres.
• Shipbuilding and Marine Workshops: Hoists lift ship sections, propulsion units, and large hatches into place. Low‐headroom variants fit under large cranes in covered dry docks.
• Mining Equipment Maintenance: Workshops servicing mining trucks and excavators use 7 t hoists to remove and install engines, transmissions, and axles in environments with heavy dust and vibrations.
• Steel Service Centers: For coil slitting and shearing lines, hoists handle raw coils (approx. 7 t each) and reposition processed coils onto packaging stations.

Conclusion

Deploying a 7 t NR electric hoist enriched the Brazilian crane rental company's product portfolio and addressed mid‐range lifting demands. The hoist's modular design and robust safety features reduced setup times by 33%, cut unplanned downtime by 25%, and increased rental utilization by 10%. Clients across construction, manufacturing, and logistics praised its precise load control and reliability under diverse environmental conditions. Beyond crane rentals, 7 t NR hoists apply to warehousing, automotive assembly, power generation, and hazardous industrial zones.