Powering a VFD (Variable Frequency Drive) with an inverter

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fordo

Joined Aug 20, 2015
18
Does anyone have any experience using battery powered inverters (E.g.; 12 Vdc --> 220 Vac) to power a VFD in a loss of utility power scenario? I would like to know if there have been any issues either with the inverter or the VFD/motor or did everything function normally. I am concerned that no matter how good the inverter is, it will never produce a pure sine wave (harmonics) and this may affect the VFD or conversely, will the switching nature of the VFD cause problems for the inverter. I currently power an Automation Direct GS2-20P5 VFD (1/2 hp) from 220 Vac single phase ("split phase") going through a LR2-20P5-1PH line reactor in series with a 20DRT1WGS EMI filter. Automation Direct and a few inverter vendors had no advice. Thanks in advance.
 

MaxHeadRoom

Joined Jul 18, 2013
23,906
Typically the input in the VFD is a 3phase rectifier and very large capacitor bank, so the nature of the source maybe not so important possibly?
 

GetDeviceInfo

Joined Jun 7, 2009
1,920
The problem you will likely encounter is during the switch over to ups. The vfd will sense and fault on the input voltage droop. You might be able to restart on power up for certain applications, or deploy a broader system that manages power outages
 

shortbus

Joined Sep 30, 2009
8,952
While not an effective answer to the question, I have a hard time visualizing what, running off a VFD, would be so important to keep running during a power failure.
 

strantor

Joined Oct 3, 2010
5,694
The problem you will likely encounter is during the switch over to ups. The vfd will sense and fault on the input voltage droop. You might be able to restart on power up for certain applications, or deploy a broader system that manages power outages
The VFD in question has a parameter to select response to momentary power loss:

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But this is mostly irrelevant because...

While not an effective answer to the question, I have a hard time visualizing what, running off a VFD, would be so important to keep running during a power failure.
The TS has another thread on the AutomationDirect forum, wherein he said that it's a large garage/bay door that he wants to be able to open during outages. It would not be a constant backup, but a 12V-240V inverter you connect to a car battery, just to be able to open the door and get out when needed.
 

strantor

Joined Oct 3, 2010
5,694
The powered ovehead roll up doors I seen in places I have worked also had a chain loop like a chain fall has to open them in that situation.
same here. I think it is a safety hazard (probably a safety violation depending on where in the world you live) to not have a redundant means of opening the door.
 
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