# problem with Schneider Altivar 71-error SCF1



## giuliothrash

Hallo everybody
I have an inverter Altivar 71 (schneider) working on a steel plant crane that sometimes (maybe once every 2 weeks...) show me alarm message "SCF1" (Motor Short Circuit); i checked everything by manual (connections, cable insulation with megger, motor insulation with megger...) and everything is absolutely ok, so i think it's a "software" error
In the plant there are many inverter like this on other cranes, but NO ONE has this problem
Somebody can help me??Just one precisation: i cannot change the inverter with a new one...
Thankyou


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## wildleg

let's see:

you have a bunch of the same pieces of equipment, and this is the only one that has an error. the error is short circuit.


I think you have an intermittent short circuit.

you notion that one out of many has a software error eludes logic. it would be more reasonable to deduct that it has the actual fault indicated. On what basis of logic, deduction, and reason would you ever conclude that this one has a software error ? (other than your inability to locate the fault ?)


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## JRaef

giuliothrash said:


> Hallo everybody
> I have an inverter Altivar 71 (schneider) working on a steel plant crane that sometimes (maybe once every 2 weeks...) show me alarm message "SCF1" (Motor Short Circuit); i checked everything by manual (connections, cable insulation with megger, motor insulation with megger...) and everything is absolutely ok, so i think it's a "software" error
> In the plant there are many inverter like this on other cranes, but NO ONE has this problem
> Somebody can help me??Just one precisation: i cannot change the inverter with a new one...
> Thankyou


If you have another drive just like this one, swap them. If the problem follows the drive, it's a drive problem. If the other drive trips, it's an installation problem.

If it is with the installation, sometimes you can get capacitance on the conductors that will trick the drive into tripping. You may have a bad or improperly done shield, or no shield at all, on the motor leads.


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## MDShunk

I guess these are traveling cables? All the meg check means is that the insulation is good in the position that the cables were in when you checked them. 

Any water infiltration?


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## McClary’s Electrical

MDShunk said:


> I guess these are traveling cables? All the meg check means is that the insulation is good in the position that the cables were in when you checked them.
> 
> Any water infiltration?


 
I agree. To complete this test more accurately, you would need to meg the circuit, while pulling the carriage through it's entire range of motion, and back again.


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## John Valdes

I have had VFD's trip like yours and even the motor shop could not find any issue with the motor. But the motor manufacturer said it was the motor. They found it. They replaced that particular one under factory warranty. (drive and motor both Baldor). 
Drives are very good at detecting the slightest problem. So good it sometimes can be an issue/problem/annoyance. 
Don't tell anyone I told you this, but. Disconnect the grounding conductor (chassis ground) and try it. (start it up). If it will run without the ground connected, you do have a short somewhere. Most likely in the motor, or the conductors serving the motor. Take it loose from the drive first, then at the motor to nail it down. Reconnect it back at the drive before you take it loose from the motor. This is not recommended. But I will tell no one if you promise to do the same. :laughing: 
You also may be able to run the control with no motor connected depending on the control or how its set up. This also would verify if its the control or the motor.


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## giuliothrash

Ok, i have exchanged 2 inverters each-other before performing other tests, now i'm waiting if something occured
Does anybody know how can reset the fault list from inverter?


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## John Valdes

giuliothrash said:


> Ok, i have exchanged 2 inverters each-other before performing other tests, now i'm waiting if something occured
> Does anybody know how can reset the fault list from inverter?


The instructions are in the user manual. Or call technical support. Make a list/print them out, before you delete them.


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## giuliothrash

I think you're wrong, i read all the manual without finding anything, customer service didn't give me this information...something else??you've already done this procedure??thankyou


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## JRaef

giuliothrash said:


> I think you're wrong, i read all the manual without finding anything, customer service didn't give me this information...something else??you've already done this procedure??thankyou


I feel your pain. The manual for the ATV Series drives is by far the worst one I have ever encountered, I wasted a LOT of time on that drive, including numerous hours on the phone with their clueless tech support people. Even though from a hardware standpoint I think their design has some merits, I never used another ATV 71 or 61 as a result of my experiences with programming them. 

That said, I know there is a parameter to reset to the factory defaults, but I also seem to recall it was not easy to find. If I get a chance later today I'll see if I still have my notes from that nightmare project, because I'm sure I wrote down how to find that reset procedure, I had to use it several times.


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## JRaef

Found it.

Drive Menu (Menu 1) > Enter

Scroll down to Factory Settings menu, 1.12 > Enter

Select "Macro-Confuguration",

Scroll down and select "All" for all parameters,

Scrolldown and select "Go To Factory Settings" 

Select "Yes" > Enter

When it changes back to saying "No" it is done.

If you only have the cheap little LED seven segment display screen this is tougher to navigate. Let me know if that's all you have and I'll dig up the 3 letter codes you will see in the above.


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## jtashaffer

at the plant I work at, we had the same problem it ended up being the control wiring going to the e-stop and to li1 on the drive.


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