|
DUTY CLASS
START CLASS CHART
| Duty
type |
Starts
per hour |
Jogs
per hour |
Brakings
to
standstill
per hour |
Complete
reversals per
hour |
Starting
class
i.e. number of
starts or thermal
equivalent
per hour
|
S3
S3 |
6
4 |
0
8 |
0
0 |
0
0 |
6
6 |
S4
S4
S5
S5
S5 |
150
100
80
65
30 |
0
200
0
130
160 |
0
0
80
65
30 |
0
0
0
0
30 |
150
150
150
150
150 |
S4
S4
S5
S5
S5 |
300
200
160
130
60 |
0
400
0
260
320 |
0
0
160
130
60 |
0
0
0
0
60 |
300
300
300
300
300 |
|
S 3 - INTERMITTENT PERIODIC DUTY
|
Following duty types are recognised for crane application.
A sequence of identical duty cycles, each consisting of a period of operation at constant load and de-energized rest period, these periods being too short to attain thermal equilibrium during one duty cycle. In this duty type the break-away starting current does not significantly affect the temperature rise for this duty type.
Unless otherwise specified, the duration of the duty cycle is 10 minutes.
The recommended values for CDF are 25,40 and 60 percent. |
|
|
|
N
R
Ø MAX
|
= OPERATING UNDER
RATED CONDITIONS
= AT REST AND DE-ENERGISED
= MAXIMUM TEMPERATURE ATTAINED DURING DUTY CYCLE
|
|
CYCLIC DURATION FACTOR |
|
N |
|
=
|
|
|
N + R |
|
