VFD Wiring Question

[Daniel Fairly Knives]

I'm trying to wire up a VFD and it came with no instructions... here is a pic from amazon.

120 v input - 240 3 phase output

 

[bladegrinder]

N-L should be your 110 volt input and U-V-W should be the three phase output. Note I say should, you should be able to find the wiring diagram for that somewhere on the web with the model number of it. The N-L terminals are marked 220 though but that might designate the highest input voltage allowed.

 

[Daniel Fairly Knives]

Thank you Bladegrinder!


Chat tells me this... I mentioned the reviews say the 220 is maybe a typo as it is sold as a 110 unit. Hmmm....

What the terminals say (left → right)​

From your photo:

• 接地 = Ground
• N / L (220V输入) = AC input (Neutral / Line)
• U V W (电机输出) = 3-phase motor output
• TA TB TC = control/relay terminals (ignore for now)

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How to wire it (your case: 120V input → 3-phase motor)​

1. Input power (your wall power)​

Even though it says 220V, these cheap VFDs are often dual-use. If yours truly supports 120V:

• L → Hot (120V)
• N → Neutral
• Ground → Ground (green wire)

So:



Wall Hot → L
Wall Neutral → N
Ground → 接地


If you hook this up and it instantly errors or won’t power correctly, it may NOT actually support 120V despite what you were told.

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2. Motor output (3-phase)​

• U → Motor wire 1
• V → Motor wire 2
• W → Motor wire 3

Order doesn’t matter initially:

• If motor spins backwards → swap any two wires

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VERY IMPORTANT (don’t skip this)​

1. Motor voltage compatibility​

• If your motor is 230V only, this VFD on 120V input will NOT give full power
• You need a dual-voltage motor (120/240 or 208/240) wired in LOW voltage mode

2. Input current draw​

• 120V VFDs pull a LOT of amps
• Don’t run this on a weak extension cord

3. No switching on output side​

• NEVER put a switch between VFD and motor
• Always control motor via the VFD

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What TA / TB / TC are (optional)​

These are:

• Relay outputs for signaling (like “motor running”)
• Not needed to just make it spin

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Quick test procedure​

1. Wire input (L/N/G)
2. Wire motor (U/V/W)
3. Power on
4. Hit run (or jumper control if needed)
5. Check rotation

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My gut check on this unit​

I’m gonna be straight with you:

• The “220V input” label is usually NOT a typo
• Most of these cheap boards are 220V input only

If this is truly a 120V model, it’s likely:

• Underpowered
• Limited to ~1HP or less

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If you want, next step​

Send me:

• The full board / model number
• Or your motor specs plate

I can:

• Verify if it’ll actually run your motor
• Show exact parameter settings (these matter a LOT on VFDs)