What is class F insulation in motor?
The F refers to the insulation class for the windings, while the B refers to an 80°C rise (the maximum temperature rise for Class B is 80°C). This type of notation is becoming more widespread because many motors use Class F insulation, and there is a reason for that.
What does insulation class F mean?
Example Temperature Tolerance Class F: 40 oC + 105 oC + 10 oC. = 155 oC. In general a motor should not operate with temperatures above the maximum. Each 10 oC rise above the rating may reduce the motor lifetime by one half.
What is class F insulation temperature?
Temperature classes
| IEC 60085 Thermal class | Old IEC 60085 Thermal class | Maximum hot spot temperature allowed |
|---|---|---|
| 120 | E | 120 °C |
| 130 | B | 130 °C |
| 155 | F | 155 °C |
| 180 | H | 180 °C |
Is class F insulation inverter duty?
A motor with a 1.15 SF and class F insulation (for 1500 Hp and less) is rated at 125C per NEMA MG-1. Motor manufacturers classify their motors as inverter duty when they use a class F insulation.
What is a Class F insulation?
Class F. Class F insulation consists of materials or combinations of materials such as mica, glass fibre, asbestos, etc., with suitable bonding, impregnating or coating substances, as well as other materials or combinations of materials, not necessarily inorganic, which by experience or tests can be shown to be capable of operation at…
What is the insulation class of the motor?
NEMA motor insulation classes describes the ability of motor insulation in the windings to handle heat. There are four insulation classes in use namely: A, B, F, and H. All four classes identify the allowable temperature rise from an ambient temperature of 40° C (104° F). Classes B and F are the most common in many applications.
What is motor insulation?
Motor Insulation. Insulation on a motor prevents interconnection of windings and the winding to earth . When looking at motors, it is important to understand how the insulation functions and its practical application.