# Huanyang 5hp Vfd On 3hp Mill Keep Getting Error E.oc.n



## 737mechanic (Aug 14, 2016)

I have a Millport Mill varispeed "Bridgeport Clone" which is 3hp 3 Phase. I purchased a HUANYANG 5HP VFD hoping the 2hp extra rating would be more than enough to power the 3hp motor. I connected it so the frequency was always 60Hz so I could use the mills variable speed wheel and reversing switch like it was meant to be used. I set all the perimeters like I think they should be set so when I turn on the VFD the freqs are at 60Hz, Volts 220 but when I turn on the mill the VFD gives the error "e.oc.n" which I believe means over current. I have connected a amp clamp to one of the 3 phase motor wires and it shows 6.7 Amps max and the VFD is rated for 17Amps. I am guessing there is such a high initial currant draw that the meter can't pick it up but the VFD does and going into protection mode. 

Now if I manually run the frequency from 20Hz on up to 60Hz the mill runs great. Also if I use the terminal connections with a separate fwd/rev switch the VFD powers the mill fine.

Before I have to resort to rewiring the fwd/rev switch to control the VFD can anyone give me any more info on any setting or idea to try.


----------



## JimDawson (Aug 14, 2016)

Try setting the Accel Ramp to about 3 seconds or more.

Do you have the mill switch between the VFD and the motor?


----------



## Ulma Doctor (Aug 14, 2016)

did you set the initial input voltage parameters to 220v, 60 hz?
my 3 hp unit was set to 220v 50hz from the factory, i had to change the setting.
i do believe there is a HP sett ing for the motor if memory serves correctly, i'll consult my installation book and see where i put my settings
PD141 is rated motor voltage
PD142 is Rated motor current
PD144 is motor RPM
if you set those to the nameplate of the motor it may help out


----------



## Joe in Oz (Aug 15, 2016)

I agree with JimDawson. Your motor ist trying to accelerate to it's 60Hz speed in a fraction of a second and the VFD won't let it. 
PLEASE don't have the reversing switch in the motor wiring. If you switch over one day without waiting for the motor to stop completely, the VFD may not survive. In fact VFD's don't like going open circuit under load either. The resulting voltage spike will quickly damage the capacitors in it.
Rewire your main switch and reversing switch to control the VFD, NOT the power between VFD and motor.
Cheers,
Joe


----------



## 737mechanic (Aug 15, 2016)

Ok guys If controlling the VFD with the switch is the preferred method then that is what I will do.


----------



## JimDawson (Aug 15, 2016)

That's OK, you are still learning, and we are here to help. 

The only time I would have a switch between a VFD and a motor is when life and limb are at risk.  Such as a service disconnect near the motor where the VFD is remote from the motor or as an absolute panic interrupt device.


----------



## 737mechanic (Aug 15, 2016)

Got switch wired up and it works perfect. Thanks for the input.

One more thing this thing doesn't seem to have any way to turn the vfd off other than killing the main power feed to it. Is that normal or am I missing something. I hate to leave it running because the cooling fan runs so fast I can hear it all over the garage.


----------



## JimDawson (Aug 15, 2016)

Some VFD's have a fan that shuts off after a time, others that function can be programmed in.  Still others are going to require killing the main power to it.


----------



## PT. Johansen (Aug 16, 2016)

As an addition to JimDawsons comment about having a switch between the VFD and the motor.

Disclamer 
I'm not your safety nanny nor do I wish to change whatever you are doing. The following is advice only, take it as such.

Please do consider it as a service disconnect only. What I mean is that you can disconnect the motor, and be sure it wont run when you are servicing something.
As Jim writes it can be used it in utmost emergency, but dont expect it to save you from anything. Please don't consider it as a Safe stop function.
The reason is simply that when you disconnect the vfd from the motor, you loose control. The motor is basically free running, and could keep running due to initia for a long time.
It's just like a car isn't stopping immediately when removing the foot from the accelerator pedal.

If people press an emergency stop they expect the motor to stop running ASAP. This doesn't happen if you have a high initia machine and disconnect the motor.
The best thing you can do in this case is to keep the VFD connected and have a very fast deceleration ramp in the VFD.
All the VFD's I work with have a special ramp called emergency ramp/rapid stop, this is activated if you remove an input signal. This signal is not the same as the normal run/stop, so you can still have conservative deceleration under normal operation.

Some VFD's even have a safety function called STO (safe torque off), and a dedicated input as a buildin option. Be carefull of this.
http://www.industry.siemens.com/top...y/safety-functions/Pages/safe-torque-off.aspx

I have talked to some that believe that if they activate this "STO" everything is fine, safety is perfect, and the machine stops ASAP, but this is not true.
In essence the STO is doing the same as the shutoff switch. STO just makes sure that the motor can't recive power from the VFD, but it doesn't stop it. It just stops delivering power.
Whatever initia the system has, determines the time to stop. Essentially the same as a switch.

What is really needed to have the fast safety stop is a function called SS1
http://www.industry.siemens.com/top...nology/safety-functions/Pages/safe-stop1.aspx
This control both ramps and disconnects power, but this isn't standard in VFD's so there is no reason to discuss it here.


----------



## Joe in Oz (Aug 16, 2016)

One last comment from me about safety stopping a machine tool with a VFD:
I use a Huayang VFDs on my lathes and mill.
I found a way of using two separate deceleration ramps: one for normal stopping between operations and the other for emergency stops. Both are controlled stops by the VFD. The normal stop has a deceleration time of 2 seconds which is nice and gentle on belts and spindle. The emergency stop is set for 0.15seconds. It stops the 8" chuck on my lathe in about 1 turn from 1000rpm. It also makes a VERY lound "BANG" when the motor just about jumps out of its mounting! Needless to say I really ONLY use it in an emergency (never yet, except for occasional testing. 
The latter requires a hefty braking resistor to dump all the inertial energy. It also injects DC when the motor is down to 10Hz.
Most Huanyang VFDs don't have the control components for an external braking resistor, but the printed circuit and noounting holes are there. So I retrofitted tyhe missing bits and connections and all is well. Other better brands of VFD have this already built in.
The idea is NOT to let the motor coast to a stop. It just takes too long in a real emergency.
For more information on settings etc - if of interest - just ask.
Oh, I made a video of it when I first did this on my mill VFD - nearly forgot....


----------



## JimDawson (Aug 16, 2016)

PT. Johansen said:


> As Jim writes it can be used it in utmost emergency, but dont expect it to save you from anything. Please don't consider it as a Safe stop function.



I was really thinking in terms of large industrial equipment, think lumber mills and other large processing equipment.  Part of my background is in huge processing equipment, sometimes a city block long.  This is not something you would do on a machine tool as an emergency stop system.


----------

