VFD Troubleshooting

[Wigz1981]

Currently troubleshooting a Vevor A2-8055 VFD. Its for an air compressor im building. I have a 5hp 3 phase motor wired for 220 that is inverter ready. With the motor leads wired to the vfd i was receiving an OC-U fault which is acceleration overcurrent. With leads disconnected i get OC-R which is a Steady State Overcurrent. From the 220 circuit im reading about 244VAC. The vfd input is rated 208-260VAC. Its possible there is a setting for input overvoltage and its set too low. The vfd is a 7.5hp (5.5kw) model. Its a 40a circuit wired with #8 THHN. Instructions arent the greatest. Curious if anyone has used one of these for a compressor and has any setting recommendations. The circuit is bkr>vfd>mtr. I dont have an external switch. This is to test and setup the vfd and motor.

 

[mm08822]

First is to verify the vfd can support a 5hp motor with a single phase input.
The 7.5hp rating is with a 3 phase input. What is its output rating on single phase input?

Increase the acceleration time so it ramps up slower. What is it set for now?

What is max frequency set for?

Provide a list of each parameter's current value. Some of the default values could be way off for your application.

 

[Wigz1981]

10sec

 

[Wigz1981]

Its getting the fault as soon as the run button is pushed.

 

[Wigz1981]

Checking the vfd info input current is 25a. Not sure what im pulling right now need to pick up a clamp ammeter tomorrow. Just have a multimeter here.

 

[mm08822]

Provide pic of motor nameplate.
Include the connection diagram.

Take pic of motor T lead connections.

Is the motor certain to be good? Where from?.......etc.

 

[mm08822]

Remove the belt from motor so it is unloaded.

 

[Wigz1981]

Motors not connected to the vfd right now. Testing the vfd itself. Compressor is half assembled at the moment. Belts and flex hoses show up tomorrow.

 

[fitter30]

Single phase to 3 phase the vfd has to be a minimum of twice the hp to work. Motor has to be connected to vfd.

 

[Wigz1981]

Havent had the time to mess with it the past couple of days but as luck would have it i found a single phase 5hp in my area that someone is trying to trade for a three phase.

I was trying to take the cheap route with my compressor. Mine is probably from the 30s lol. Its an old Gilbarco 60 gallon. I would call it a rebranded Quincy but it wasnt even rebadged. Finding a manual for my 325 has been impossible. Its an ROC 1. Still works like a champ. It had an older Wagner 3hp Repulsion Induction motor that still runs great. Although it would suit my needs for right now im going to need more SCFM from it so i can paint my car.

The tank had a ton of rust (surface) inside the tank. I was going to refurbish it but when i was pressure testing it i noticed it leaking and apparently it had a drain valve at one point and it busted off and left a mess on the threads. The guy that sold it said it had an air leak. I ended up replacing it with a 120gal Steelfab horizontal for a steel.

Im Gas Turbine Electrician in the Navy. I deal with VFDs on a daily basis. Control systems are my bread and butter. This was my first time using one of these cheaper chinesium units. Im used to Allen Bradley/Siemens/Mitsubishi, etc… if i could have gotten one from work i definitely would have taken that route but we mainly use 480v 3 phase to 480v 3 phase. We use them for speed control.

Finding the drawing for the motor didnt turn much up but it isnt that unique. The label plate had the Model # Blank. Its a 6 lead wye/delta (208v/230v/480v) w/ thermal protection. Motor thermal fuse and the coils read good. Issue was definitely just a configuration issue with the VFD.

I appreciate everyone taking the time to help. You would think being in the Navy it would be easy to get help being within that community but im at 17 years and electrical work isnt just my job but a hobby for me as well so its hard to find someone around me that knows more than i do. We had a separate rating (job) called Electricians Mate. They should be the resident experts for us but im the Senior guy (im the Chief Petty Officer for our electrical shop.

Sorry if this turned into a tangent. Havent had many chances to talk shop lately

 

[mm08822]

Next time go through each parameter and make sure the defaults are what your application needs.

Lenze makes a nice vfd product. More expensive than Chinesium but less than RA.

BTW, what was wrong?

 

[u3b3rg33k]

if I was getting an overcurrent error with no motor connected, I'd suspect the VFD was probably bad. I've never seen that happen on a known brand drive.

who OEMs VFDs for VEVOR?

 

[walta]

Motors not connected to the vfd right now. Testing the vfd itself. Compressor is half assembled at the moment. Belts and flex hoses show up tomorrow.

To my ear this sounds like a recipe for weird error codes. Find a small motor just to give it a load.

Walta

 

[Hank11]

Vevor vfds have a very poor reputation, so don’t be surprised if its bad out of the box.

 

[RPH]

Converters don’t like open outputs with no load. You can get different fault codes depending on the fault tree. In the small induction units, an open output faulted as high frequency fault. It could find the resonant frequency within its given range. Other units, it would manifest as an over current fault. It makes sense if you understand the electronics. Others utilize different fault messages for open output.
You need somewhere for the current to flow providing the converter with the proper feedback to continue gating on/off the transistors to generate the waveforms.
Shorted output can cause some of the same faults. When troubleshooting converters it takes awhile to understand how it all works!

 

[rocksnstumps]

I have several of the Vevor vfds. A couple are the A2 models but lower kw (HP). They all power up and can change parameters with no motor connected. Preferred in my opinion because some parameters will need to be changed from factory default and don't need faults right away.

With no motor wired, would think the accel parameter at 10 sec is probably a moot point. But would leave there for now.

Don't believe the the A2 series has a parameter for setting upper and lower voltage faults. My one unit (H100 series) which is a bit different from A2 models does however.

The one difference in wiring I noted between the models was the A2 has input terminals R, S, T and you wire the 240v hots to R and T skipping the middle terminal. Maybe check this first.

The H100 series has input terminals L1, L2, L3 and you wire the two hots to L1 and L2 adjacent to each other.

The H100 has way more parameters to play with including low and high voltage faults. The readout from that unit shows 219v when running a motor. Your 244 volts does seem high.

Otherwise faulting with no motor wired does seem maybe unit is junk from factory.