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Ask Brian HVAC Guy Your Own Question
Brian HVAC Guy
Brian HVAC Guy, HVAC Technician
Category: HVAC
Satisfied Customers: 771
Experience:  I have been an HVAC/R mechanic/technician for 30+ years.
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I have a Trane TR 1 Series VFD. The unit was not running at

Customer Question

I have a Trane TR 1 Series VFD. The unit was not running at the time of the fault. It has a Alarm Code 60 External Fault. The book only shows. A warning 60. but no Alarm 60
Submitted: 5 months ago.
Category: HVAC
Customer: replied 5 months ago.
Let me know if you need anymore info.
Customer: replied 5 months ago.
Send me a Text if you ever have a answer to my question. Thank You
Expert:  BillyHvac replied 5 months ago.
I am very sorry your question has not been picked up yet.I just logged on and found you had not been assisted. Please let me know if you still need help and I will do my best. Please do not "Rate" as we have not worked toward an answer yet. If you would like to proceed let me know by replying. Once again use reply
Customer: replied 5 months ago.
No I have not got any response. Do you need anymore info. Like the VFD also does not work in ByPass but will ramp up on the VFD to 30 HRZ in test. But does not ramp up motor. I am not at work right now. But I will try and answer any ?
Expert:  Brian HVAC Guy replied 5 months ago.
Hello, an external interlock alarm is an indication that the unit is set to remote control and there is no start signal being given (no permission to run). This is why the drive would work in test. It should also work if you put the drive in local control. If your drive is controlled by a remote device (remote start/stop switch, building automation system, etc...) then that remote device is causing your headache. If the drive is not being controlled remotely and only by the local keypad control, then it should be set to local control. You may also have to disable the remote start digital input or jump the associated digital input out physically. Why is it all of a sudden doing this? I have no clue but it could be a glitch or a line spike that corrupted the memory or even another operator's error. Bot***** *****ne, check the remote start issue and clear it or put the drive in local control and disable remote start digital input. -Brian
Customer: replied 5 months ago.
Like I stated earlier. The drive does not work in ByPass Which you call manual. When you put it in test The test ramps up to 30%. But not the motor. It does not work in Auto. And I already know that it is an external interlock. Determined that two days ago. With that being said. I should be able to put the unit in ByPass with an external interlock alarm and it should run the pump. But it does not. The hole idea of bypass. Is that it bypasses the controls.
Expert:  Brian HVAC Guy replied 5 months ago.
I'm sorry but we were on two different pages here. When I read: "The drive does not work in ByPass", that tells me that a physical contactor switching mechanism has been engaged thereby electrically bypassing the drive entirely and running the motor across the line. That is the accepted definition of a VFD bypass. Of course the drive won't operate while the control is in bypass. Are you having a problem with the bypass or the VFD or both. It sounds like both to me. If by putting the drive in 'Manual' you mean switching from remote to local control, then let's call it local control. VFD's can be put in auto whether being controlled locally OR remotely. That's why I suggested looking at programming. I can't be there to see your application so I have to rely on your explanation of things. If this is a Danfoss made for Trane drive (VLT series) this is usually caused by a power fail or corrupted memory and a check of the entire program parameters is in order. If you have a remote start digital input assigned then jump it out and see if the drive runs. It's important to know what mode the drive is intended to operate in and what is controlling it whether local or remotely. If by manual you mean putting the drive in "Bypass", and you have a motor that won't run in bypass, then you have a problem in the bypass or in the motor itself that is separate from any problem you may or may not have with the VFD. Lastly, I called nothing "manual". I'm using the proper terms for a VFD and control system: Local or Remote control; Bypass or VFD control; and Hand or Auto control. All six are distinct and different modes. Not all drives have all six modes available. I'm afraid this is beyond my scope to help you here since we are not only not on the same page but in different books. I'll opt-out in hopes one of the other techs here can help. please don't post another reply until you get a reply from another tech. If you do, it will only delay help further. Thanks,-Brian

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