Service Factors
Service Factors chart
Load Conditions Service Factors
Continuous driving Loads vary only slightly 1
Applied torque varies during operation 1.5
Applied torque varies during operation, 'stop' and 'go' cycles are encountered often. 2
Small shock and radical torque variations are applied. 2.5
Heavy shock or normal reversing drives are loaded 3
Reversing torque load doesn't always imply reversal of roatation ask person in charge
Service(Safety) Factor for each running part
General Applications Service Factor Industrial Applications Service Factor
AGITATORS 1.5 - 2.0 Aggregate Processing Cement 2.0 - 3.0
BLOWERS 1.0 - 1.5 Bewery & Distilling 1.0 - 2.0
COMPRESSORS 1.0 - 1.5 Food Industry 1.0 - 2.0
CONVEYERS 1.5 - 3.0 Lumber Industry 1.5 - 2.0
CRANES & HOISTS 2.0 - 2.5 Power Industry 1.5 - 2.5
ELEVATORS 2.0 - 2.5 Pulp & Paper Mills 1.0 - 2.5
FANS 1.0 - 2.0 Rubber Industry 1.0 - 3.0
GENERATORS 1.0 - 3.0 Steel Industry 2.0 - 3.0
PUMPS 1.0 - 2.0 Textile Industry 1.0 - 2.0
Temperature Service Factor
Ambient Temperature Service Factor St*
50º < Tº 66º 0.25
66 < Tº 74 0.5
74 < Tº 82 0.75
82 < Tº 93 1
* For relative humidity < 50%
for humidity relative > 50% consult engineers

In common, the service factor adjustment for high temperature is in addition to the service factor consideration for the driver and driven equipment. However, if high temperatures are typical for a specific application, maximum temperature consideration is incorporated into the "typical" service factor (e.g steel mill tables conveyors).