Brand new induction motor arrived in the factory,it comes with gearbox on top controlled by VFD, but I could not understand it's nameplate, it should have shown just delta / star without voltage number, so confusing.
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1\$\begingroup\$ It just shows the motor can be connected in wye OR delta. \$\endgroup\$– StainlessSteelRatMay 30, 2022 at 3:25
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\$\begingroup\$ It is sort of implied that the motor can run at 220 V 50 Hz when wired delta and 380 V 60 Hz when wired Y. If it were a NEMA motor that is how I would interpret it, anyway. But maybe it is just saying that the motor can run at either frequency. \$\endgroup\$– user57037May 30, 2022 at 6:04
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\$\begingroup\$ IF your VDF is power from single-phase mains voltage (220V 50Hz). Then you need to use a delta connection. Otherwise (3 - phase 380V) use a star connection. \$\endgroup\$– G36May 31, 2022 at 14:22
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\$\begingroup\$ G36 you probably right, so you have to look what voltage output of VFD ,then follow delta or wye accordingly, right ? \$\endgroup\$– user295305May 31, 2022 at 14:44
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\$\begingroup\$ Yes, because if you only have a single-phase power supply input for a VFD, the output of a VFD will only provide 220V 3-phase output. Thus, you need to use a delta. But if your VFD "input voltage" is from a 3 phase system (380V), then you need to connect a motor in a star/wye fashion. \$\endgroup\$– G36May 31, 2022 at 15:11
1 Answer
You're mistaken.
The motor phase voltage is 220 V.
When connected in star, the line voltage is 220 * √3 = 380V.
When connected in delta, the line voltage is the same as the phase voltage i.e. 220 V.
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1\$\begingroup\$ Yes - that's correct. The Wye voltage will always be larger than the Delta voltage for a three-wire connection, since there are two coils in series, versus one. The terminal diagrams provided in the nameplate show how the motor is connected for Wye and Delta. For Delta, connect U1 to W2, V1 to U2, and W1 to V2 and use x1 as the power terminals. For Wye, connect x2 together and again use x1 as the power terminals. \$\endgroup\$– HypeInstMay 30, 2022 at 3:18