What is the meaning of Duty S1 in electrical drives?

Question

Let me know about other duty classes.

Answer 1

The eight - S1 - S8 - IEC duty cycles of operating electrical motors

IEC (the International Electrotechnical Commission) uses eight duty cycle designations to describe an electrical motors operating conditions:

S1 - Continuous duty. The motor works at a constant load for enough time to reach temperature equilibrium.
S2 - Short-time duty. The motor works at a constant load, but not long enough to reach temperature equilibrium. The rest periods are long enough for the motor to reach ambient temperature.
S3 - Intermittent periodic duty. Sequential, identical run and rest cycles with constant load. Temperature equilibrium is never reached. Starting current has little effect on temperature rise.
S4 - Intermittent periodic duty with starting. Sequential, identical start, run and rest cycles with constant load. Temperature equilibrium is not reached, but starting current affects temperature rise.
S5 - Intermittent periodic duty with electric braking. Sequential, identical cycles of starting, running at constant load and running with no load. No rest periods.
S6 - Continuous operation with intermittent load. Sequential, identical cycles of running with constant load and running with no load. No rest periods.
S7 - Continuous operation with electric braking. Sequential identical cycles of starting, running at constant load and electric braking. No rest periods.
S8 - Continuous operation with periodic changes in load and speed. Sequential, identical duty cycles run at constant load and given speed, then run at other constant loads and speeds. No rest periods.

Answer 2

Generally a SERVICE Factor of 1 means you can run the device at full rated amperage for a continuous load time. However there are SE and SF drives that are for severe service and have service factors greater than one. They can be started under loads, ramp to drive speed then stopped and do it all over again , time after time....In the areas of DC and AC controlling drives many times you have to watch what your getting because the service of the device may be rated for the enclosure NOT the device itself . You can buy a Ne-ma 1 starter in a Ne-ma 12 enclosure and still only be getting a light duty drive controller. Since most drives nowadays are in some way or another speed and frequency controllers . The designer must find the balance point between the Duty service and the Drive size. I have found it a wise decision to always get the drive Representative on the phone before making any decision i might be sorry for later.....Good luck from the E

Answer 3

This Site Might Help You.

RE:
What is the meaning of Duty S1 in electrical drives?
Let me know about other duty classes.

Answer 4

S1 - Continuous duty. The motor works at a constant load for enough time to reach temperature equilibrium.

Answer 5

Motor Duty Cycle

Answer 6

Equipment works to the rated duty, when a motor rated 2000RPM rotates 2000times u can say 100%, when a generator produces excactly as it rated then u has generator with 100%, u need to explain ur qstn well.

Answer 7

*Duty Cycle: The relationship between operating time and the resting time of an electric motor.
*Duty is a statement of the loads to which the machine is subjected, including starting, electric braking, no-load and rest and de-energised periods, and also their durations and sequence in time.
However, duty type is a continuous, short-time or periodic duty, comprised of one or more loads remaining constant for the duration specified, or a non-periodic duty in which generally, load and speed vary within the permissible operating range.
Electric motors are manufactured as adaptable to various operating conditions. Standard duty types are classified by

IEC 60 034-1:

*S1 : Continuous running duty.The motor works at a constant load for enough time to reach temperature equilibrium.
S2 : Short-time duty.
Operation at constant load for durations of 10, 30, 60 and 90 min are recommended. After each operating period, the motor has to be de-energised for a sufficient duration until the windings are cooled to ambient temperature.
S3 : Intermittent periodic duty.
The starting current does not significantly affect the temperature rise.
Duty cycle is 10 min unless otherwise agreed.
Cyclic duration factor of 15%, 25%, 40% and 60% may be considered.
S4 : Intermittent periodic duty with starting.
Starting has influence on temperature rise of windings.
Starting load-torque (N), number of starts per hour, cyclic duration factor and factor of inertia (Fl) have to be given.
S5 : Intermittent periodic duty with electric braking.
Starting and brakings have influence on temperature rise of windings.
Starting load-torque (N), number of starts per hour, cyclic duration factor and factor of inertia (Fl) have to be given.
S6 : Continuous-operation periodic duty.
There is no temperature rise when the motor is loaded at its rated output.
Duty cycle is 10 min unless otherwise agreed.
Cyclic duration factor of 15%, 25%, 40% and 60% may be considered.
S7 : Continuous-operation periodic duty with electric braking.
Brakings have influence on temperature rise of windings.
Load and factor of inertia (Fl) at the operating period have to be given.
S8 : Continuous-operation periodic duty with related load/speed changes.
Brakings have influence on temperature rise of windings.
Load, cyclic duration factor and factor of inertia (Fl) for each speed at the operating period have to be given.
S9 : Duty with non-periodic load and speed variations.
Brakings have influence on temperature rise of windings.
Load and factor of inertia (Fl) for each speed have to be given.

Cyclic duration factor is the ratio of the period of loading, including starting and electrical braking, to the duration of the duty cycle and is expressed as a percentage.


Factor of inertia (Fl) = JM =Jz
JM


JM : Moment of inertia of the motor (kgm2)
Jz Total moment of inertia of driven machine and parts as couplings etc... referred to motor shaft (kgm2)

The nature of braking, whether mechanical or electrical (D.C. or reversed current) has also to be stated.
The ratings and performance data given in this catalogue,are for continuous running at constant load for a sufficient duration to reach thermal equilibrium which correspond to duty type SI.
However, standard range motors may be operated at all the other duty types, provided that the limit of permissible temperature rise is not exceeded.
http://www.industrialmotion.co.uk/products/motors/techspec/13_duty_types.htm
http://www.engineeringtoolbox.com/iec-duty-cucles-d_739.html