Stahl ST10 - 7.7 Checking Chains

7 Inspection and maintenance
38 01.2019
ba-o.1.8.0-en-3.1
Check backlash of motor shaft - brake.
• Bottom hook block unloaded
• Brake closed
Turn the motor shaft with the fanwheel (4) back and fore.
If there is noticeable backlash the brake must be replaced.
7.6 Travel motor brake
See operating instructions of travel drive
7.7 Checking chains
7.7.1 Check condition of the chain
1. WARNING Damaged chains can break during operation and cause serious injuries
and a load crash.
➢ Check chains for damage such as cracks, deformation and corrosion.
2. With visible damage or corrosion, replace the chains.
3. Operate chain hoist with load.
4. If heavy clicking noises arise, check the lubrication and wear of the chains, chain
drive wheel, and return sheaves.
5. If necessary, perform relubrication or replace worn components.
7.7.2 Check wear of the chains
Type
ST 05
[mm]
ST 10
[mm]
ST 20
[mm]
ST 30
[mm]
ST 32
[mm]
ST 50/60
[mm]
dxt
4x12
5x16
7x21.9
9x27
9x27
11.3x31
d min
3.6
4.5
6.3
8.1
8.1
10.2
t max
12.5
16.8
23
28.3
28.3
32.5
k max
134.4
179.66
245.92
303.18
303.18
350.37
The dimension “k” can be checked with a chain wear gauge “X” or a caliper “Y”.
1. Check the chain length “k” with 11 chain links respectively at multiple points.
2. Compare the determined values with the max. permissible value “k max” (see table
above).
3. If “k max” is exceeded, replace the chain.
4. Measure the dimensions “d” and “t” at multiple points.
5. Compare the measured values with the permissible values “d min” and “t max” (see
table above).
6. If “d min” is undershot or “t max” is exceeded, replace the chain.
Chain wear gauge
Caliper