The service life of the hoist is divided into many Safety Working Periods (SWPs). The SWP% of the new hoist is 100 while the safety work period begins. When the SWP% is zero, the safety work period expires. A thorough general overhaul (GO) shall be carried out after the end of a safety work period. Afterwards, the hoist will be subject to a new safety work period. Please refer to the contents of the section “General Overhaul”.
During the SWP, the safe and effective operations of the hoist depend on the periodic maintenance.
Please carry out the inspection and maintenance steps listed in the following table in order to maintain the safety and working efficiency of the hoist.
The hoist must be maintained and serviced in strict accordance with the specified time limit in order to avoid the spark of the explosion-proof hoist resulting from the friction among the mechanical parts. Otherwise, it will endanger the safety of the equipment.
Routine inspection
Please conduct the following routine inspections while each work shift begins.
Please use the hoist in the appropriate circumstance. If the circumstance cannot be judged, please feel free to contact the service agent designated by the manufacturer! The operation of any defect hoist may lead to the serious damage of the equipment or even the people casualties.
| 1 | Check the wire rope: Ø Check the steel cables: whether any steel cable or wire rope is twisted, crushed, corroded or broken; Ø Check whether the wire rope has been put into the reel slot and pulley. |
| 2 | Check the hook block: Ø Check whether the hook can move freely in all directions; Ø Check whether there is any safety plug and whether it is valid; and. Ø Check whether the drum can rotate freely and smoothly. |
| 3 | Check the limit switches for hoisting operations: Ø Verify whether the upper limit switch can operate correctly; Ø Check whether the lower limit switch can operate correctly. |
| 4 | Check the button controller: Ø Check the button controller to see whether there is any sign of wear or crack in the rack and whether the button has been loosened or broken. Ø Check whether the functions and operating methods of all buttons and switches are normal; Check whether the Emergency Stop button can operate correctly. During the test, do not press the Emergency Stop button while the hoist works. The correct method is as follows: press the Emergency Stop button when it is in a neutral state so as to ensure that the button cannot start any operation. |
The maintenance interval of the hoist is defined as the time bucket of SWP%. The actual operations of the hoists shall be taken into consideration in the SWP%. The SWP value can be read from the screen of this status monitor if the hoist is equipped with such a monitor. Please refer to the Operation Instructions of the condition monitoring device for more information. The SWP% corresponding to the SWP value can be read from the table below. Check the label attached to the hoist to make definite the classification of operation levels of the hoist.
| SWP Value relating to SWP% | ||||||
| ISO (FEM) Work Group of the Hoist | ||||||
| M3(1Bm) | M4(1Am) | M5 (2m) | M6 (3m) | M7 (4m) | M8 (5m) | SWP% |
| 400 | 800 | 1600 | 3200 | 6300 | 12500 | 100% |
| 360 | 720 | 1440 | 2880 | 5670 | 11250 | 90% |
| 320 | 640 | 1280 | 2560 | 5040 | 10000 | 80% |
| 280 | 560 | 1120 | 2240 | 4410 | 8750 | 70% |
| 240 | 480 | 960 | 1920 | 3780 | 7500 | 60% |
| 200 | 400 | 800 | 1600 | 3150 | 6250 | 50% |
| 160 | 320 | 640 | 1280 | 2520 | 5000 | 40% |
| 120 | 240 | 480 | 960 | 1890 | 3750 | 30% |
| 80 | 160 | 320 | 640 | 1260 | 2500 | 20% |
| 40 | 80 | 160 | 320 | 630 | 1250 | 10% |
| 20 | 40 | 80 | 160 | 320 | 625 | 5% |
| 4 | 8 | 16 | 32 | 63 | 125 | 1% |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The following tables have displayed the maintenance intervals of the hoist respectively according to SWP% time bucket and calendar months. The specific inspection and maintenance items shall refer to the detailed description and introduction of the previous sections of the Operation Instructions. The maintenance codes must be carried out shortly after the end of one SWP% time bucket or when the specified several months are about to come. As for the hoist without any condition monitoring device, the maintenance code must be carried out by months. The maintenance time intervals shall be as short as possible in order to ensure the availability of the hoist.
If the ambient temperature is often higher than 40 ºC (104 ºF), the maintenance and servicing intervals shall be half of the intervals listed in the following table.
X= only the service personnel authorized by the hoist manufacturer or the work staff fully trained by the hoist manufacturer can perform the periodic inspection and maintenance. The detailed rules of inspection for various parts shall refer to the corresponding sections or chapters.
C= user executes the routine inspections.
| Inspection/maintenance item | Interval | ||
| Shortened SWP% | 10% | ||
| Classification of the hoists | All | ||
| Calendar interval period and years | 1 | ||
| 1 | Check the trolley wheels 1) | X | |
| 2 | Check the buffer 1) | X | |
| 3 | Check lifting machinery and couplings | X | |
| 4 | Check the gears of the hoist | X | |
| 5 | Check the motor and brake of the hoist | X | |
| 6 | Check the limit switches for hoisting operations: | X | C |
| 7 | Check the button controller | X | C |
| 8 | Check the guide-rope gear 1) | X | |
| 9 | Check the frequency controller 1) | X | |
| 10 | Check the rope reel | X | |
| 11 | Check the guide-rope device | X | |
| 12 | Check the rope clip | X | |
| 13 | Check the drum brake 1) | X | |
| 14 | Check the wedge socket | X | |
| 15 | Check the hook block | X | C |
| 16 | Check the pulley wire rope 1) | X | |
| 17 | Check the steel cable | X | C |
| 18 | Check the overload protector | X | |
| 19 | Check the status controller 1) | X | |
| 20 | Annual inspection made as per local requirements 2) | X | |
The theoretic service life of the hoist is over when the SWP% of the hoist reaches zero.
Therefore, the possibility of fault in the hoist will be higher, which will endanger the operating safety. It must get a general overhaul (GO) to the hoist when its theoretic service life is over.
Only the hoist manufacturer or the service agency authorized by the hoist manufacturer can perform the general overhaul.
It is necessary to check the components of the hoist that will affect the service life the hoist during the overhaul, and the important parts shall be replaced.
The new theoretic SWP of the hoist shall be given out after the overhaul is over.
After the SWP of the hoist is over, the hoist cannot be used only after it has been overhauled.
It is necessary to calculate when the SWP will be over according to the Standard FEM9.775 if the hoist is not equipped with the supporting condition monitoring device.
