KNIGHT SMART CART OPERATION MANUAL
SECTION 4
MAINTENANCE
14
4.3 Determining the Frequency of Chain Inspections
Knight recommends utilizing load criteria and duty cycle data when determining the frequency of
inspections. Inspection frequency should be identified by a qualified person and is based on factors
such as the severity of the environment the cart is being used in, percentage of capacity lifts, cycle
time and shock loading. Each Smart Cart should be rated individually and inspections performed in
accordance with that rating.
Proper maintenance depends on an evaluation of the severity of usage to which the cart and the
chains are subjected to in the specific application.
The overall determination of how often the cart and chains should be inspected is a combination of its
Service Rating Load Criteria (4.3.1) and its Service Class or Duty Cycle (4.3.2).
4.3.1 Service Rating Load Criteria
Light Service
: Cart and chains normally subjected to light loads and very rarely to maximum
loads.
Moderate Service:
Cart and chains normally subjected to moderate loads but fairly frequently to
maximum loads.
Heavy Service:
Cart and chains normally subjected to loads of heavy magnitude and frequently
to maximum loads.
Very Heavy Service:
Cart and chains regularly subjected to maximum loads.
4.3.2 Service Class (Duty Cycle)
Service Class is determined by the total number of cycles the system has performed. (Table 4-1)
•
Service Class 0: 0
to
20,000 loaded cycles.
•
Service Class 1: 20,001
to
100,000 loaded cycles.
•
Service Class 2: 100,001
to
500,000 loaded cycles.
•
Service Class 3: 500,001
to
2,000,000 loaded cycles.
•
Service Class 4:
over
2,000,000 loaded cycles.
Cycles Per Day
Desired Life (Years)
1
5
10
20
30
5
0
0
0
1
1
10
0
0
1
1
2
25
0
1
1
2
2
50
0
1
2
2
3
100
1
2
2
3
3
200
1
2
3
3
4
300
2
3
3
4
4
750
2
3
4
4
4
1,000
2
3
4
4
4
Table 4-1: Service Class
Example: If the system is performing 100 cycles per day, it will progress though Service Classes
during its use:
1 year
26,000 cycles
Service Class 1
5 years
130,000 cycles
Service Class 2
10 years
260,000 cycles
Service Class 2
20 years
520,000 cycles
Service Class 3
30 years
780,000 cycles
Service Class 3
