Why Copper?

The use of copper in place of aluminium can lead tosignificant benefits:

Higher efficiency
A first possibility of design is to get higherefficiency, while using approximately the same motor size as thealuminium rotor version. Copper’s higher electrical conductivityallows the rotor to conduct electricity more efficiently, resultingin lower resistive losses and lower operating temperature.
Extended life expectancy
As motor life is doubled for every10°C reduction in operating temperature, this lower operationaltemperature results in extended motor life expectancy.The lower operating temperature combined with the highthermal conductivity of copper allows for fewer forcedcooling units. This further improves efficiency.
Smaller size and cost
A second design avenue consists inthe reduction of the overall size and weight of the motor byusing a copper rotor, while maintaining the motor efficiency.This is because the higher efficiency of the copper rotor allowsthe overall length of the rotor (and motor) to be decreased,while still matching the performance of a motor utilizing analuminium rotor. Shortening the motor eliminates some of therotor and stator laminations; decreases the number of statorwindings; and reduces the length of the shaft. A more compactand lighter machine is possible, and the rotor more easily fitsinto a monoblock motor system.

Why Not Copper?

Copper melts at 1083°C, compared to 660°C for aluminium.The higher melting point of copper has historically led to die-castingproblems. In fact, the die-casting of (pure) copper was technicallydifficult or virtually impossible for a long time. This meant thatcopper had not been greatly utilized for industrial rotor production.

However, all these problems now belong to the past, thanks to theavailability of new processes.

2 Pole

Frame Size

Stacking Height(mm)

Rotor OD(mm)

Rotor End Ring Height(mm)

80

M1

65

72

<=20

M2

90

<=20

90

S

105

77

<=20

L

125

<=20

100

L

110

90

<=20

112

M

125

98

<=20

132

S1

120

116

<=20

S2

145

<=20

160

M1

150

150

<=20

M2

195

<=20

L

220

<=20

180

M

235

165

<=20

200

L1

210

187

<=20

4 Pole

Frame Size

Stacking Height(mm)

Rotor OD(mm)

Rotor End Ring Height(mm)

80

M1

90

80

<=20

M2

105

<=20

90

S

125

85

<=20

L

160

<=20

100

L1

130

105

<=20

L2

165

<=20

112

M

195

110

<=20

132

S

160

136

<=20

M

200

<=20

160

M

175

170

<=20

L

225

<=20

180

M

220

187

<=20

6 Pole

Frame Size

Stacking Height(mm)

Rotor OD(mm)

Rotor End Ring Height(mm)

90

S

120

90

<=20

L

165

<=20

100

L

120

114

<=20

112

M

150

120

<=20

132

S

130

148

<=20

M1

155

<=20

M2

210

<=20

160

M

180

180

<=20

L

230

<=20

180

L

220

205

<=20

200

L1

215

230

<=20

8 Pole

Frame Size

Stacking Height(mm)

Rotor OD(mm)

Rotor End Ring Height(mm)

100

L1

73

106

<=20

L2

93

<=20

112

M

90

120

<=20

132

S

85

148

<=20

M

110

<=20

160

M1

85

180

<=20

M2

120

<=20

L

170

<=20

180

L

150

205

<=20

200

L

150

230

<=20