Introduction to the fiberglass laminated sheets for motor slot wedges

1. What is the motor slot wedge? Although it looks inconspicuous, the slot wedge is an essential part of the m...

1. What is the motor slot wedge?

Although it looks inconspicuous, the slot wedge is an essential part of the motor winding system, especially in high-voltage motors. Slot wedges embedded into the iron core slot can ensure that the winding is firmly fixed in a relatively static state, subsequently impregnated with paint, and cured together with the winding.

2.Products used as motor slot wedges

ZTelec Group offers the following six types of fiberglass laminated sheets used as motor slot wedges:

fiberglass laminated sheets used for motor slot wedges

2.1 G10 epoxy fiberglass laminated sheets

G10 is made of electronic grade alkali-free fiberglass cloth impregnated with epoxy resin and hot pressed, conforming to IEC60893-3 and GB/T1303.4 standards. Insulation grade B, temperature resistance: 130℃. Color: green, yellow, and black. G10 has smooth surface, and neat edges, with stable electrical insulation performance and standard thickness tolerance.

2.2 3240 epoxy fiberglass laminated sheets

3240 epoxy sheet is made of alkali-free fiberglass cloth impregnated with epoxy resin and hot pressed, in accordance with IEC60893-3 and GB/T1303.4 standards. Insulation grade B, heat resistance: 130℃. Color: yellow. 3240 epoxy sheets are suitable for insulating structural parts in electrical, electronic, and motor industries.

2.3 3241 semi-conductor fiberglass laminated sheets

3241 semiconductor glass cloth laminate is made of alkali-free glass fiber cloth as reinforcement material, adding carbon black, and then impregnated with epoxy resin by drying and hot-pressing technology. The insulation grade is B, the temperature resistance is 130℃, and the color is black. Semi-conductor board has high mechanical strength, high voltage resistance, and radiation resistance, suitable for anti-corona materials in medium- and large-scale motors and can be used as wear-resistant structural parts at high temperature.

2.4 Magnetically conductive sheets

The magnetically conductive sheet is made of glass fiber cloth, soft magnetic material and composite resin by one-time sizing into semi-cured sheet, and then hot pressed by laminated sheet. The color is black. This laminated magnetic guide plate has high permeability, excellent mechanical properties, good processing performance, and is suitable for processing various types of motor slot wedge.

2.5 G7 organic silicone fiberglass laminated sheet

The G7 board is made of alkali-free fiberglass cloth impregnated with organic silicone resin by hot pressing technology. It is self-extinguishing when burnt and works well in both wet and dry environments. Insulation grade: H, temperature resistance 180°C. The G7 sheet has strong mechanical and dielectric properties, radiation resistance, arc resistance, and is suitable for structural parts in electrical insulation of class H. Color: white or light green.

The fiberglass products mentioned above are suitable for different types and insulation levels of motors. The shape and dimensions of these products must match well with the motor punching slot, otherwise there will be serious quality risks, and therefore the requirements are quite strict in the actual production and processing of the slot wedge.

motor slot wedges

3. Consequences caused by loose motor slot wedges

Loose slot wedges may make the motor winding lose restraint, in the process of operation generating low-frequency electromagnetic vibration, further resulting in radial displacement in the slot; or causing scratches at the slot liner and leading to multipoint short circuit in the stator core, both of which can cause winding to ground failure. If the slot wedge pops out, it will cause local heating of the winding, in serious cases even burnt down.

Therefore, choosing the right material for the slot wedge is crucial for the normal operation of the motor. All the above fiberglass laminated products produced by ZTelec Group can be cut as per customer's requirements. We can also provide customized processed parts according to the drawings. If you are interested, welcome to contact us.