FEM Working Class

Working Class is a associated with mechanical life. If you decide to choose a crane, you should selected the corresponding FEM working class according to the actual conditions to promise your investment to be more reasonable.
The selection of FEM working class should consider two factors: Load type (Load range)(K) and ART/Per Day (Average Running Time Per Day) (Tm).

1) Load type (Load range)
Light (K≤0.5)
Occasionally Full Lifting Load, usually Lighter Lifting Load, small Fixed Load.
Medium (0.5＜K≤0.63)
Occasionally Full Lifting Load,usually Lighter Lifting Load. average Fixed Load.
Heavy (0.63＜K≤0.8)
Repeatedly Full Lifting Load, usually Average Lifting Load, heavy Fixed Load.
Very Heavy (0.8＜K＜1)
Usually Full Lifting Load, heavy Fixed Load.

2) ART/ Per Day (TM): TM is Average Running Time Per Day, including Loading and No-loading.

3)

Load level ( Load Scope)		ART per day (Hour)
Maintenance	K	＜0.5h	＜1h	＜2h	＜4h	＜8h	＜16h
Light	K≤0.5	-	1Cm	1Bm	1Am	2m	3m
Medium	0.5＜K≤0.63	1Cm	1Bm	1Am	2m	3m	4m
Heavy	0.63＜K≤0.8	1Bm	1Am	2m	3m	4m	5m
Very Heavy	0.8＜K＜1	1Am	2m	3m	4m	5m	-

4) FEM working class censorship
Need to inspect on-load factor and start times per day
On-load factor =(Lifting time + fall time)／(Lifting time + idle time + fall time + idle time)

Working Class	1Bm	1Am	2m	3m	4m
On-load factor (ED)	25%	30%	40%	50%	60%
Start times per day	150	180	240	300	360
	250-day Full load operation per year
	400	800	1600	3200	6300