DEMAG DC-Com 1, Operating Instructions Manual

Page: 66 / 116

The actual duration of service is considerably increased if the chain hoist is only operated with partial loads. For a
hoist unit operated on average with half load, for example, this results in an 8-fold increase in the actual duration
of service; with operation at one quarter of the full load, a 64-fold increase.
8.3.4.2 Calculating the actual duration of service S
The actual duration of service S of the electric chain hoist can be determined as follows:
S = k
mi
x T
i
x f
k
mi
: Actual load spectrum factor
T
i
: Number of operating hours
f : Factor depending on the type of recording
Calculating the number of hours of operation (operating time) T
i
(by the owner)
The operating time can be calculated by means of an elapsed time indicator or according to the following method:
Operating time per inspection interval:
T
i
=
(l lowering) x cycles/h x operating time/day x days/inspection interval
60 x lifting speed
Tab. 43
Only lifting and lowering movements are counted, long and cross-travel times are not considered.
Estimating load spectrum factor k
mi
(by the owner)
To simplify estimation, each type of load can be grouped together into k
m
load spectrum modules. The types of
load are simplified and quoted as 1/4, 1/2, 3/4 load and full load.
Dead loads are added to the loads. Loads up to 20% of the rated load capacity are not considered.
The operating time for each type of load is divided up within the inspection interval (e.g. 1 year) in terms of per‐
centage.
The following bar diagram shows the k
m
load spectrum modules for the load conditions without load up to full load
in time increments of 5 and 10%. Larger shares of the time period must be correspondingly added together.
Load spectrum factor k
mi
can be obtained by adding together the individual k
m
load spectrum modules.
Diagram
Fig. 34
B Loading L Load t Time 1 Dead load
Tab. 44
Factor depending on the type of recording
● f = 1,1
For calculating the operating hours using an elapsed time indicator (included in the DC-Com standard scope of
delivery).
● f = 1,2
For estimating the operating hours and the load spectrum.
8.3.4.3 Example: DC-Com 10-1000 1/1 H5 V4/1 in 1Am
Lifting speed 4/1 m/min
No. of cycles per hour 10 cycles/h
66
214
80
2 44/291
113