DEMAG DC-Com 1, Operating Instructions Manual

Page: 65 / 116

DC chain hoist
Motor size Display value C for U
nom
380 - 575 V Display value C for U
nom
220 - 240 V
1
ZNK 71
80 80
2 80 60
5 ZNK 80 60 50
10 ZNK 100 A 50 20
10 ZNK 100 B 20 -
Tab. 41
Display value C specifies the expected service life of the contactor multiplied by 100000. This value was deter‐
mined under normal operating conditions. For other conditions, the service life of the contactor may be shorter or
longer,

"Display of software version, operating hours, number of cycles", Page 30.
We recommend that the contactor or the control module be replaced when the relevant display value has been
reached,  "Replacing the contactor on the control board", Page 92.
8.3.4 S.W.P. measures for achieving safe working periods
8.3.4.1 General
The safety and health provisions of the EC Machinery Directive make it a legal requirement to eliminate special
hazards which may be caused, for example, by fatigue and ageing.
This requirement is also reflected in the third supplement to German accident prevention regulations UVV/
BGV D8 of 1.4.1996.
This requirement obliges the owner of serial hoist units to determine the actual duration of service of the chain
hoist on the basis of the operating hours, load spectra and/or recording factors. This is based on
FEM 9.755/06.1993 Measures for achieving safe working periods for powered serial hoist units (S.W.P.).
The objective of this rule is to determine measures for achieving safe working periods over the entire duration of
service, although, according to the state-of-the-art, the chain hoists are designed for specific periods of operation.
Premature failure cannot, however, be ruled out.
The following items have been taken from FEM rule 9.755 with reference to the electric chain hoist:
1. The actual duration of service determined on the basis of operating time and load must be documented at
least once per year.
2. Operating time T
i
(number of operating hours) can be estimated or read on an elapsed time indicator.
3. Load k
mi
(load spectrum) must be estimated.
4. The value determined for operating time T
i
using an elapsed time indicator must be multiplied by the type of
recording factor f = 1,1.
5. The value determined for the estimated operating hours and load spectrum must be multiplied by the type of
recording factor f = 1,2.
6. The actual duration of service S is calculated as: S = k
mi
x T
i
x f
7. A general overhaul must be carried out when the theoretical duration of service is reached.
8. All checks and inspections and the general overhaul must be arranged by the owner of the hoist unit.
A general overhaul is defined as:
Inspection of the machinery for the purpose of detecting all defective components and/or components and parts
close to failure and the replacement of all such components and parts. Following a general overhaul, the machi‐
nery is in a condition similar to that of the same machinery in new condition as far as the principle of operation
and performance values are concerned.
For electric chain hoists classified according to FEM 9.511, the following theoretical durations of service apply
(converted into full load hours):
Group of mechanisms 1Cm 1Bm 1Am 2m 2m+ 3m 4m
Duration of service/full load hours
[h]
200 400 800 1600 1900 3200 6300
Tab. 42
214
80
2 44/291
113
65