Motor service factor (SF) is
the percentage multiplier that a motor can handle for short periods of time when operating within its normal voltage and frequency tolerance
. In other words, it is a fudge factor that give extra horsepower when it's occasionally needed. A SF is an operational margin.
What is 1.15 service factor?
Motor Service Factor (SF) is the percentage of overloading the motor can handle for short periods when operating normally within the correct voltage tolerances. … This means that a 10-hp motor with a 1.15 SF could provide
11.5 hp
when required for short-term use.
How do you calculate the service factor of a motor?
Calculate or determine your service factor by
choosing the service factor that corresponds to your hp and various RPM levels
. For example, according to the table, if you have a 1HP motor and you operate it at 3600 RPM continuously, your service factor is 1.25.
What is a good service factor?
The service factor – SF – is a measure of periodically overload capacity at which a motor can operate without damage. … A motor operating continuously at a service factor
greater than 1
will have a reduced life expectancy compared to operating at at its rated nameplate horsepower.
What is Pump Service factor?
Generally, service factor is
the measurement used to determine the peak performance at which a pump motor can operate
. The National Electrical Manufacturers Association (NEMA) defines service factor simply as a multiplier that indicates the amount of additional load a motor can handle above its nameplate horsepower.
What is safety factor of motor?
Engineers should choose a safety factor of
1.5 to 2.25
according to most documentation and motor selection guides. The drive should be expected to output enough energy for the amount of Torque that the motor should supply.
What power factor means?
Power factor (PF) is
the ratio of working power, measured in kilowatts (kW), to apparent power, measured in kilovolt amperes (kVA)
. … PF expresses the ratio of true power used in a circuit to the apparent power delivered to the circuit. A 96% power factor demonstrates more efficiency than a 75% power factor.
Is service factor the same as safety factor?
Service factors are used to account for
higher torque
conditions of the equipment to which the coupling is connected. … Safety factors are used in the design of a coupling. Coupling designers use safety factors because there are uncertainties in the design.
Is the most common cause of motor failure?
Low Resistance
. The most common cause of motor failure, and arguably the most difficult to overcome, is low resistance. Low resistance is caused by the degradation of the insulation of the windings due to conditions such as overheating, corrosion, or physical damage.
What does SFA mean on a motor?
Service Factor Amps
, or S.F.A., represents the amount of current the motor will draw when running at the full Service Factor. In the example nameplate, the S.F.A. is eight amps at 230 volts. Continually exceeding the S.F.A. shown on the nameplate can shorten motor life.
What is the ratio of factor of safety?
The factor of safety is defined as the
ratio of ultimate to working stress
(in case of brittle material). The factor of safety may also be defined as the ratio of the resisting force to failure causing force.
What is service factor of generator?
The standard which defines the service factor for motors and generators is
the MG-1 standard
, which in turn defines powers and speeds. Likewise, for each power and speed, the MG-1 standard defines a frame number which is linked to the service factor.
What is gear service factor?
In simple terms, the service factor is
the ratio of the gearbox rated horsepower (or torque) to the application's required horsepower (or torque)
. … In general, the horsepower (or torque) rating of a gear tooth is based on the durability of the gear surface — its resistance to pitting — or on its bending fatigue.
What is service factor of induction motor?
Motor service factor (SF) is
the percentage multiplier that a motor can handle for short periods of time when operating within its normal voltage and frequency tolerance
. In other words, it is a fudge factor that give extra horsepower when it's occasionally needed. A SF is an operational margin.
What is motor power factor?
The motor power factor is
the phase angle between voltage and current (cosφ)
. cos phi (φ) is used, among other purposes, to calculate the power consumption of a motor. … Cosφ is the phase angle between voltage and current. Cosφ is also referred to as power factor (PF).
What is pool motor Service Factor?
The Service Factor is
a measure of the capacity at which a motor can operate without overload or damage
. A motor's effective horsepower, or total horsepower, is the actual power output of the motor. You can determine this by using the nameplate to multiply the horsepower and the service factor together.
