HLV-H speed control motor running backward.

[alchr]

I recently moved my 1961 Hardinge HLV-H to a different shop and hooked it back up to the same rotary phase converter. The spindle turns the right direction but the speed control motor runs backward. "Faster" get you slower and so on. Also not the limit switches on the speed control gear box also do not work.

I thought that all of the HLV-H used the 3 phase drive for the spindle and the control system was 110 single phase.
Could this be as simple as switching two of the 22o 3 phase input wires?

Any help is always appreciated.

Allen

 

[rons]

The speed control motor is 3 phase. The carriage speed motor is run from single phase. You answered your question.

 

[Billtodd]

Allen,

Both the speed jack motor and main motor run from the same 3ph wiring, so the input connection must be wrong.

It can be important to ensure that the machine's control transformer is run from the live phase (not the generated phases), so do check this.

Bill

 

[hitandmiss]

If you have run the speed control motor the wrong way into a limit, you may have damaged the gear on the end of the screw, it is made to fail easily if this is done.
Billtodd is correct on both points.

Bill

 

[alchr]

My lathe was wired for 440 volt input and the previous owner had installed a step up transformer on the back of the machine to allow it to run on 220 volt 3 phase input. It ran just fine at my old house that way.

I never checked the inputs there so I was just lucky.

I just checked the voltage at the 3 phase breaker going to the lathe and two legs are at 116 volts to ground and one phase is at 206 volts to ground.

The T1 control transformer tag states a 220 volt o 440 volt primary with a 115 volt secondary so it must have 2 different primary windings I am guessing.

With the unbalanced 3 phases going into the step up transformer I am not sure what to expect out of that transformer?? I have not checked the output of the step up transformer.

Any suggestions?

thanks,

Allen

 

[hitandmiss]

The voltages look OK to ground. You should measure your voltages phase to phase.

If your spindle motor is dual voltage and has 18 leads, it can be rewired to 220 volts. Otherwise it will need the transformer.

Make sure the direction switch on the electrical panel is set for forward operation.
Bill

 

[alchr]

I will check the input voltage phase to phase in the morning. I assume that I need to have one of the two lower voltage phases hooked to T1 machine input which goes to the control transformer, is that right.

Is the speed control motor also a 440 volt motor if the machine was factory wired for 440 volt 3 phase?

 

[Billtodd]

Please be careful with 440vac, it is far nastier than 220v

Isolate the power. Trace the wires from the control transformer back through the main isolator to the step-up transformer(s). Mark those pair as 'live' (the 1961 US diagram I have here shows the CT connected between L1 & L3 at the isolator).

The 'live' phase from the RPC is likely to be the same voltage as the mains input, the generated phases will be different voltages, so just measure and ensure the 'live' phase makes its way via the step-up transformer to the control transformer.

If necessary just swap the live phase wires at the input until the spindle runs in the correct direction.

The speed jack motor is likely to be 440v only - i.e. only three wires from the motor (especially if the main motor is 440v only) , so you'll probably have to keep the step-up transformer.

T1 will probably be a standard control transformer, so will have various primary and secondary taps (if it worked OK before the move, I'd leave it as it was )

Bill

P.S. a good photo of the control box and step-up transformer would help

 

[jim rozen]

First off the carriage motor =/= to the spindle speed control motor.

Second, the spindle speed control motor is indeed three phase.

Third, if the speed control motor runs backwards it will hit the limit
switches and be unable to 'back out.' You can recover from this
by turning the (greasy) leadscrew by hand to get it off the limit.

If the spindle runs forward when commanded to run foward, and
the speed control works backwards, somebody's monkeyed with the
wiring. Invert two leads on the speed control motor to get the desired
results.

 

[alchr]

Is it correct to assume that the Live Phase is the one with the higher voltage (206 V or so at the breaker box) since the other two phases are almost identical and lower? That is the phase that should be going to the Control Transformer, right?

The lathe ran fine for years at the old shop and no one messed with any wiring other than disconnecting it from the junction box when I moved it.

Is it also correct that there is only one phase arrangement (hook up) that is correct?

 

[hitandmiss]

"Is it correct to assume that the Live Phase is the one with the higher voltage (206 V or so at the breaker box) since the other two phases are almost identical and lower? That is the phase that should be going to the Control Transformer, right?" Absolutely NOT. The phase that is 206 to ground is the manufactured phase, and must NOT feed the control transformer.

" Is it also correct that there is only one phase arrangement (hook up) that is correct?" Yes that is correct, since there are no pictures of the inside of your control box, there are certain things that need to be done in order . Step#1 first then go to step #2 to guide you through the process of getting it connected properly.

1. Please swap 2 phases of your input power, so the speed control motor turns the right way, before there is internal damage to the speed changer gearbox.

2. Verify that the fwd/rev selector on the side of the electrical enclosure is in the FWD position.

3. If the spindle is still turning backwards, this will be addressed last.

4. To get the machine power transformer on the correct phases. I am assuming that you will ALWAYS turn the phase converter off before connecting or disconnecting wires.

A. Disconnect the phase that has 206 to ground.

B. "The T1 control transformer tag states a 220 volt o 440 volt primary with a 115 volt secondary so it must have 2 different primary windings I am guessing."
Yes there should be 4 terminals for input power, wires to the outside two and a jumper between the middle two. Power up and measure the voltage across the outside two, should be near 440 Volts.

C. If you measured 440 on step B, skip the rest of this step, it is wired correctly.
If way less it is connected to the manufactured phase, now measure the voltage at the top of the disconnect left 2, right 2, and outside 2.
Only one of the three readings will have 440 on it. Please post your measurements, and I will tell you how move the wires to get it wired properly.

D. Reconnect the phase disconnected in step A.

E. Check operation, Speed change rotation correct? Spindle rotation correct? Post results.

Bill

P.S. If the spindle motor has 18 leads it is a dual voltage motor. And if the speed change motor has 6 or 9 leads, it also is a dual voltage motor. And you can reconnect them to the lower voltage with the proper instructions. We need to know what you have first.

 

[alchr]

I managed to catch some kind of virus so I haven't done much here. I want to be thinking clearly when I am around 440 volts.

Sunday, I did reverse the wires at the breaker box, upstream from the transformer, and the spindle and the speed control continued to run backward after switching?? What is going on in the step up transformer?

I had this machine running correctly at my old shop using this same phase converter?

Hopefully I can get out tomorrow and run the checks that Bill suggested above. I will switch the input wires in the box on the end of the lathe cabinet to make sure of the T1 voltage.

I have the speed control motor system in the middle of the range to keep from hitting the stops.

 

[hitandmiss]

You need to swap 2 phases after the phase converter. Swapping the phases in the single phase panel will not change rotation

Note:

In post #1 you said The spindle turns the right direction but the speed control motor runs backward.
In post #7 you said the spindle and speed control continued to run backward after switching.

So if post #1 is in error, this simplifies things. Do not run the speed control motor until the spindle is turning the correct direction.

Bill




Bill

 

[Billtodd]

Bill is correct (us Willhelms usually are )

Just to clarify what we mean by phases:

There are three wires from your RPC (typically labelled L1, L2 & L3) between each pair of wires are three phases so

L1 & L2 = first phase
L2 & L3 = second phase
L3 & L1 = third phase

The mains input to your house going to the RPC is a single '220v' phase (which can vary +/-10% and is split about earth/ground*, hence each measure 116vac to ground ) . This will pass through your RPC and appear as one of the phases above (we don't know which) and should be the one that makes it via the step-up transformer to the control transformer (CT) in the machine - I call this the 'live' phase and the other two 'generated'.

Once you have ensured that the 'live' phase is wired to the CT, the machine's motors can be reversed by swapping over the two wires that carry the live 'phase' at the step-up transformer or output of the RPC (this will change the two 'generated' phases and change the direction of the motor)


Bill

* In the UK, the domestic single phase supply is grounded at source on one side so we get a Live wire (at 230vac nominal) and Neutral wire at earth potential.

 

[alchr]

Switched L1 and L2 and all is well now.

Thanks for the help.

Next step is to open up the carriage to take care of the pinion gear to rack gear slack.

There was someone on this forum that was making these a while back, does anyone remember?

 

[Billtodd]

Switched L1 and L2 and all is well now.

Great stuff

 

[PapaJohn]

Hi all -

New member here. I've got a similar situation - I just bought and installed a 1962 HLV-H, 220 3Ph, powered via a new American Rotary AR5 PC. After wiring all up, the spindle turned backwards, so I swapped the live phase wires (L1 & L3 go to the CT) and now the spindle spins correctly...but the speed control motor is reversed (up is down, and...). I checked the wiring diagram (LH-8220), and someone had changed the SC motor connections from the wiring diagram's T1R-T1T6(motor), T2R-T2T4(motor), and T3R-T3T5(motor) and swapped T1R and T3R (T1R-T3T5 and T3R-T1T6). I'd like to think it was changed for a reason, but not sure why, or how to find out. Is there any potential harm in simply rewiring the SC motor back to comply with the wiring diagram?

One other thing - the voltage between legs seems high for two: L1L3 = 242V (live phase), L1L2 = 270V (mfd), and L2L3 = 265V (mfd). Are these manufactured voltages excessively too high, to the point of causing problems?

Thanks in advance,

John

 

[rons]

One other thing - the voltage between legs seems high for two: L1L3 = 242V (live phase), L1L2 = 270V (mfd), and L2L3 = 265V (mfd). Are these manufactured voltages excessively too high, to the point of causing problems?

Before question #1. Identify the L1, L2, & L3 wires. Which is the manufactured one from the idler motor? Then measure L to L voltages with power on and lathe motor
running. These are the numbers to look at.