Understanding Duty Cycles for Hoists and Cranes
When buying a hoist or crane, you may encounter various numbers and letters in the specifications. These codes provide crucial information about the duty cycle, indicating how long the equipment can operate and how much rest it needs to prevent overheating and ensure longevity. Hoist and motor duty cycles are noted in different ways as recognised by the various authorities that govern the industry.
Duty Cycles for Motors
The duty cycle for motors is often represented by an “ED” rating, which stands for “Einschaltdauer” (which translates to ‘duty cycle’). This rating, expressed as a percentage, specifies the proportion of time a motor can operate within a 10-minute period before needing a cooldown. For example:
- 40% ED: The motor can run for 4 minutes, followed by 6 minutes of cooling.
Understanding these ratings helps in selecting the right motor for your hoist or crane, ensuring optimal performance and lifespan.
FEM and ISO Ratings
When you see a specification like 2m/M5 for a hoist or crane, it provides essential information about the equipment’s operational standards according to two different organisations: European Federation of Materials Handling (FEM) and International Organisation for Standards (ISO).
FEM Rating (2m)
- The number 2m indicates the classification of the equipment’s durability and operational capacity according to FEM standards.
- This classification helps determine the expected lifespan and performance of the hoist or crane under specific operational conditions.
ISO Rating (M5)
- The code M5 signifies the equipment’s rating according to ISO standards.
- Like the FEM rating, the ISO rating provides a standardised measure of the equipment’s durability and operational efficiency.
Both FEM and ISO ratings aim to establish a certain lifespan for cranes and hoists, typically around 10 years, under defined operating conditions. These ratings help buyers and users understand how well the equipment can handle specific workloads and operational environments, ensuring they choose the right equipment for their needs.
ISO/FEM Rating Comparison Table
Here’s a comparison table to help you understand how these ratings apply to your new hoist or crane:
Average Daily Operating Time ISO/FEM (hours per day) |
||||||
Load Spectrum | ≤0.5 | ≤1 | ≤2 | ≤4 | ≤8 | ≤16 |
Light | M3 1Bm |
M4 1Am |
M5 2m |
M6 3m |
||
Medium | M3 1Bm |
M4 1Am |
M5 2m |
M6 3m |
M7 4m |
|
Heavy | M3 1Bm |
M4 1Am |
M5 2m |
M6 3m |
M7 4m |
|
Very Heavy | M4 1Am |
M5 2m |
M6 3m |
M7 4m |
Choosing the Right Equipment
Selecting the right hoist or crane involves understanding your operational needs and matching them with the appropriate duty cycle and rating. When choosing a hoist or crane, it’s important to consider:
- Operational Environment: Is the environment dusty or wet? Does it involve heavy-duty operations?
- Frequency of Use: What is the daily average operating time?
By choosing the right-rated equipment, you ensure it can handle the workload without frequent maintenance or downtime, enhancing the longevity and efficiency of your machinery while also ensuring the safety and productivity of your operations.
At RGM Cranes, we provide a wide range of hoists and cranes designed to meet high standards of durability and reliability. Our products are equipped with accurate duty cycle ratings and adhere to FEM and ISO standards, ensuring they can withstand even the harshest environments.
Need some assistance choosing the right equipment? Contact our team.