# Lenze AC Controller VFD Upgrade



## Johny (Jul 21, 2008)

Does anyone here have experience with the internals of Lenze 9300 series industrial Variable Speed Controllers?
Specifically, the Lenze 9327, 9328 and 9329 (16, 22 and 30kW) all come in the same case size and weight. I have pulled my 9327 apart and it looks as if standard larger IGBTs will fit but I need to find out what stumbling blocks await me. I know that TECO VFDs let you change the Model in a parameter but Lenze play it a bit closer to their chest. I know I'll either have to change what the controller 'thinks' it really is, or lie to it about the motor current.
Any info anyone?


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## cts_casemod (Aug 23, 2012)

Johny said:


> Does anyone here have experience with the internals of Lenze 9300 series industrial Variable Speed Controllers?
> Specifically, the Lenze 9327, 9328 and 9329 (16, 22 and 30kW) all come in the same case size and weight. I have pulled my 9327 apart and it looks as if standard larger IGBTs will fit but I need to find out what stumbling blocks await me. I know that TECO VFDs let you change the Model in a parameter but Lenze play it a bit closer to their chest. I know I'll either have to change what the controller 'thinks' it really is, or lie to it about the motor current.
> Any info anyone?


 
General rule you have to change a few things like the current sensors. The drive will still read the same output, but the real output will be greater. If you make sure the drive is kept cool and you have good DC BUS capacitors you could also add 10% more to the output keeping the same components.

If you upgrade the IGBTs the carrier frequency must be reduced or new gate drivers/power supplies will be required.

Some lenze (AC TECH) units use IPM and not standard IGBTs. Same rules apply, but you only need to upgrade the power supply since the driver is part of the IPM


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