Deckel FP-1 VFD conversion keeping the original electrical panel

[laminar-flow]

Having recently lost my phase perfect solid state converter, and the new phase perfect not running the unique Deckel motor correctly, my son and I looked into converting to a single VFD. We wanted to keep the original Deckel functionality and the electrical cabinet, but how with a two speed motor and a high speed head motor? Although some including I have done it, VFD’s are not to be switched on output. He devised a way and it works great.

So the main 220 feeds directly to a TECO 3hp 220 VFD, a split was used to power the control transformer, which is powered all the time as is the VFD. The original Deckel start buttons close the existing Deckel relays as before and the power from the three lights, Low Speed, High Speed, and High Speed head were used to trip the relays which starts the VFD. The VFD is left at 60 Hz. There is a slight delay on the VFD and it is set to ramp up to full speed. (frequency), in about 2 seconds. This has an added benefit of not clacking the gears as I’m sure all of us FP-1 users know about. The switching of the output original Deckel contactors occurs about .25 seconds before the VFD power arrives.

 

[ballen]

A circuit diagram would be very helpful. Is the VFD programmed for the main motor? or for the motor in the high-speed head? Or is it one of those VFDs that can be programmed for multiple motors? What happens if you set the switch for the high speed head and turn it on without the high speed head plugged in?

 

[laminar-flow]

Because it was quite simple, we didn't sketch out a diagram, yet. The VFD was not programmed for any particular motor as they are similar. Press the High Speed head button and the contactor closes and the VFD ramps up. Press the High Speed head button with the motor plugged in and the same happens and the motor ramps up.

 

[AlfaGTA]

Wire looks a little light, but maybe it’s the angle.
I thought the high speed head was selected by being plugged into its dedicated socket on the electrical cabinet.
What do you do about having power feed when using the high speed head?
Curious to know why the Phase Perfect couldn’t run your machine without this workaround?

Cheers Ross

 

[laminar-flow]

The red wires are control and the three larger black wires from the VFD to the panel terminals are the power. The High Speed Head question is a good point. But when one uses the HSH, the main motor would be started first if needed then the HSH motor. This is to keep the main motor from starting at 60 Hz and clacking the gears like it used to. But it would not really matter. I tested it either way and it seems fine adding load to an existing load. The main red off button turns them both off.

 

[1potatoe]

The VFD would have no trouble running both motors at the same time. My 2hp VFD runs my 2hp Seimens 2 speed motor and the high speed head easily.

 

[1potatoe]

But..— I don’t use the original 70 year old controls on my FP1.—

 

[1potatoe]

I’m not sure a VFD should be used for anything other than running a three
phase motor

 

[AlfaGTA]

No answer as to why the "new" Phase Perfect did not work.
Cheers Ross

 

[laminar-flow]

Not exactly sure why. The 3hp PP is heading back to PP to get checked. It could be it, or it could be it not compatible with the FP-1 motor, which is a bit weird. The 3HP PP ran other motors I have just fine. The DPC 10 ran the FP-1 for 22 years just fine. So not determined yet.

 

[AlfaGTA]

PP web site says that the 3hp converter is not good for hard starting loads. Not the same machine as your original DCP10
Likely the answer , thanks for the info.
Cheers Ross

 

[laminar-flow]

The 10HP was bought 22 years ago because that is all they had.

1) Two months ago I did check with PP about which unit to buy and they said the 3hp unit should start a 3hp motor under load.

2) The new PP would start the FP-1 motor fine several times and then start it rough and in several seconds smooth out. The PP always got the FP-1 motor up to speed in less than .5 seconds, exactly as the old unit did. When it was on one of its rough starts, it still came up to speed as fast, but the PP two legs were low until it either shut down or smoothed out upon which the voltages came back up. https://www.practicalmachinist.com/...-of-phase-perfects.393784/page-3#post-4069004

3) Sometimes the new PP would just shut down with nothing on the load. The error was "low input voltage" sometimes, which was not the case.

4) The FP-1 motor does not start under much load. The PP did the same thing whether it was started with the FP-1 gearbox at 1K or on 0 with no load. An example of a high load start are pumps, maybe a lathe with a big chuck, etc.

5) The other motors in the shop, one larger than the FP-1 low side, started just fine every time.

6) The FP-1 motor has a ∆-Y (low-high) configuration but the several EE's I'be been talking to say that the FP-1 motor on low should be fine and any problem should be on the high speed config. And the center leg of the Y is open so it still should appear as a ∆ config. PP said the new PP's have increased protection than the older ones and that sometimes caused problems.

But since I have a good education in the scientific method, I make no conclusions and let the data tell me what is going on. I'll report back when the PP is evaluated.

 

[adrian]

Reading through this article I am a little confused as to how you are running the original Deckel motors (or any other two speed three phase motor) from a 240V supply as both the original motors are 415V and not dual voltage.

As you know three phase motors switch speed by changing the pole connections from delta to star. In my experience the star configuration requires a 415V supply. This can be achieved with rotary converters as they step up the input voltage from 240 to 415V but this is not the case with VFD’s which can only output the supply voltage.

A single phase 240V input inverter can only supply a 240V motor, however the three phase input type can drive 415V motors.

The other issue is one of motor overload protection. The high speed head requires different motor settings to the main motor within the inverter and I am not sure how it would reach to having two different motors connected and switched separately.

Inverters are cheap so why not get a smaller one for the high speed head, however we come back to the same issue of voltage.

Having gone through this process with my Deckel and Mikron I decided to bin all the guts in the control cabinet and start a fresh. The original components having been in a workshop environment for 60++ years are well past their best by date along with brittle wiring, outdated switches, relays and contactors.

Going to the trouble of installing VFD’s you should take advantage of their features. Adding controls for variable speed and Jog For/Rev are the useful features I would not be without.


Regards Adrian.

 

[laminar-flow]

I had this FP-1 for over 30 years and always run it on 220 3 phase, rotary for 10, phase perfect for 20. It says that on the tag. My electrical cabinet has been kept in a clean heated and cooled shop for that time so it looks fine. We were wondering about the high speed head also but it runs smooth and seems fine.

 

[adrian]

I understand now, you are using a three phase supply. Do machine motors supplied to the American market take 220V in star or delta configuration unlike those in Euro land.

 

[laminar-flow]

I think that is correct, but the center of the Y does not seem to be connected to ground.

 

[adrian]

Three phase motors don't use a neutral in either star or delta configurations
Machines use the neutral however for transformers and other low voltage control.

 

[laminar-flow]

Phase perfect reports that the 3HP unit was received and tested normal. They offered a refund with a 20% restocking charge. So it looks like the problem was it running the Deckel FP-1 motor.

 

[drcoelho]

What I would do:
- start with a properly sized Phase perfect to generate 3 phase
- drop in a step-up transformer to get to 400V
- lose the VFD....you are trying to run multiple motors and controls off a VFD, not an ideal situation

 

[laminar-flow]

Why would I need 400 Volts?