Mill is 3-phase 440v, I have 1-phase 220v - What kind of options do I have?

Ron

Where are the forward / reverse controls and the switches to start / stop the motors etc?

Wich I was closer, could have this sorted out lickety split for you.

Walter
 
Ron,

Check the labeling on the smaller twist-lock plug. I'm thinking it says "125V 15A." If so, you could either instal a matching twist-lock receptacle or replace the cord end with a standard, non-twist like you have on nearly everything in your house. As Walter pointed out, it's likely an add-on to power accessories like the DROs or plug-in tools.

Walter,

An added advantage to covering all the bases in your replies is that someone who reads this a year from now will have all of the info. Ron may have the complete picture in half the words, but the next guy may need all of them to stay out of trouble.
 
starlight_tools said:
Ron

Where are the forward / reverse controls and the switches to start / stop the motors etc?

Wich I was closer, could have this sorted out lickety split for you.

Walter
Click to expand...

If you were closer you'd most likely get very frustrated with me. Just ask my wife. ;):biggrin:


The forward/reverse switches for the motors are mounted on the motors themselves. They are just simple mechanical switches. (Back motor same as front.) The large switch housing down on the front/side of knee is the switch that directs power to either the vertical or horizontal motor. You can see the two cords going into it on the bottom. Those are the two cords marked as "E" on the first photo in the previous pic post.

Hawkeye said:
Ron,

Check the labeling on the smaller twist-lock plug. I'm thinking it says "125V 15A." If so, you could either instal a matching twist-lock receptacle or replace the cord end with a standard, non-twist like you have on nearly everything in your house. As Walter pointed out, it's likely an add-on to power accessories like the DROs or plug-in tools.

Walter,

An added advantage to covering all the bases in your replies is that someone who reads this a year from now will have all of the info. Ron may have the complete picture in half the words, but the next guy may need all of them to stay out of trouble.
Click to expand...

You're right, and I will check that better tomorrow when I remember to bring my keys with me. :eek: :banghead: I just assumed it to be 220v as that's the kind of plug I use for my welders and my computer systems here at the office.

Thanks guys,

-Ron
 
Last edited by a moderator:
Ron

Looks to me to be just staight mechanical drum switches, so I would ass/u/me that you could rewire to 220V 3 phase and not worry about anything else.

Using a continuity tester, switch the power switch to "forward" and lower switch to "top motor" and test for continuity between the three hots of the plug. You should have continuity through all four switch combinations to all three "hot" blades of the plug. Resistance reading should be slightly different between the top motor and the rear motor, but not by much. If so, this will mean that you do not have any magnetic switches in the machine.

You should also have coninuuity between the ground blade of the plug and the frame of the mill in all combinations.

Walter
 
Thanks Walter. I think we are on the same page there (especially with the ass/u/me part. :biggrin:). I'll dig out my Fluke when I get the chance and check things out but it certainly appears that all the switches are purely mechanical.

That being the case (if), I can simply re-wire them for 220v 3-phase. I will then just need to have an RPC with 220v single "in" and 220v 3-phase "out". If I understand things correctly (and that's always up in the air) I would also like to have a TLC between the RPC and the mill. I looked at the link you sent to me earlier but didn't see (may have just missed it) any references to a TLC, at least not by that acronym. I don't like to impose but could you please point me in the proper direction for that? While I'm at it, are the TLCs rated for current, voltage, power consumption, or output HP or just a passive monitor that throws a breaker?

Thank you,

-Ron
 
The TLC, Timing Line Contactor, is just a large magnetic contactor, with a coil voltage that matches the output voltage of the unit, so in this case it would 220V.

The three wires from the output of the RPC are connected to the input of the contactor and then the three wires from the output continue on to your Load centre, or fuse block then onto the machine.

The control circuit for the TLC is a bit more complicated, there is a timer and relay circuit that is wired into the RPC so that once the unit is operational it will automatically start. The PhaseMAXX units I supply have this wired in from the factory. One would have to inquire with the factory as to what would be entailed to add this feature to an existing unit.

Another method to consider would be just using a stock Magnetic switches. One switch needs to be between the main circuit breaker and the RPC, unless the RPC has this feature built in. Doing this will remove power from the RPC should the power go out which will prevent the unit from auto-repowering when the power comes back on. The PhaseMAXX units have this feature built in, but "homemade" units often do not and if the power is applied to an RPC that needs a secondary means of starting the generator motor, the generator will be damaged if power is applied to lines 1 and 2 but the generator is not rotating.

A second Magnetic switch would be used on the output of the RPC and you would manually switch it on once the RPC is operating.

Ron, in your case, the big question is, will you or do you want to get an RPC that will allow you to operate more than one machine? If you will only ever power up this one mill with the RPC then it can be simplified. BUT and this is a big BUT, if you figure you may possibly add more 3 phase machines down the road then look more towards getting a larger RPC that has capacity to handle the future anticipated load.

RPC's are like air compressors, buy a small one to handle the immeadiate need and realize quickly how useful they are, then get more tools that need even more air.

Walter
 
Okay, I think I've got a handle on the TLC thing thanks to you Walter. (I have now forgotten my street address and age. Hey, there are only so many brain cells left! ;))

The size of an RPC was going to be the next question so I am very glad you brought it up. There is always the possibility that I find other 3-phase powered equipment I may want to add, as a group we never seem to quit looking. :p :biggrin: That being the case one has to decide just how much HP one should get. While I figure this is only limited by one's budget, I believe I've seen listings for RPCs that state there is a "minimum" HP that can be run on the units. What do you know/have to say in this regard? Are some that way and others (better designed I would assume) not?

Thanks once again,

-Ron
 
Ron

If you use too large an RPC it will just consume too much power. Remember that your max breaker size in your panel will ultimately limit the total HP you can operate.

I put in the 7-1/2 HP by 22 HP unit. The largest motor this will handle is 7-1/2 HP in a class 1 Non-CNC application, and you can run multiple motors up to a total of 22 HP. The largest Class 2 motor is 5 HP and Class 3 is 3 Hp. If going CNC it will handle a 3 HP largest motor and a total of 3-3/4 HP max load

Now let's talk class ratings.

The heavier loaded the motor is at starting is its class. A compressor running in the freezing cold is somewhere between a Class 2 and a class 3, I know as my 5 HP 3 Phase compressor, starts fine in the summer, but in -15 Deg C weather it gets really hard to start.

A motor starting with no load on it is Class 1

Then we throw CNC into the mix and that further reduces the capacity of a RPC.

My preference for a small home shop system, whether for wood working or metal working is the 7-1/2/22 or the 10/30

This gives room to grow into.

a 3/9 like I sent you the PM quote for limits you to smaller machines, not that 3 Hp is all that small.

Now as you get larger capacity of machines, if you run a really small motor on them, they are not that sensitive so can fluctuate the voltages a bit too much for the little motor. In that case we add a VLS (Voltage Level Sensor) or Voltage Regulator, this way small motors do not get harmed by the larger system. without the VLS, yes they have a lower limit. But say you have a lathe like mine which is 3 HP drive motor and 1/8 HP coolant pump motor, that VLS is now very important to the coolant pump motor.

Also any system 7-1/2 Hp or larger should have the soft start feature which helps to prevent browning out the neighbourhood when you start up the RPC.

So to sum up, 3/9 would be the minimum system requirement for you today, but no room to grow into larger toys.

3/9 minimum, 5/15 OK, 7-1/2/22 better or even better 10/30 would be my recommendations. If you plan to CNC your machine then these recommendations need further review.

As I said, I got the 7TZ, 7-1/2 / 22, but I have wished that I had gone with the 10 TZ - 10/30 as there are times when I have found the other a bit small, such as mid winter starting the 5 Hp compressor which I got for "cheap" as the seller was having a hard time finding a buyer. 3 phase is not very popular in this area and even commercial shops avoid it because hydro charges big bucks to install it.

If you go 5 or larger add the VLS
If you go 7-1/2 or larger add the Soft Start

On all af them have the TLC factory installed.

There are a number of brands of RPC's out there, I have found that the PhaseMAXX has been the best quality and has the best availability of add-ons like VLS, Soft Start and TLC, so that is the brand I have been using and selling to my clients.

Avoid static converters like the plague!

See here for more info on the systems we supply

http://www.electram.com/Advertising/brochure2010.pdf

Walter
 
Great information Walter! It gives me quite a bit to think about as well. You mention the "brown out" and "different for CNC" which brings up another concern I hadn't given much consideration to and that is, "Just how "dirty" is this kind of power supply?". The transformer I get my "shop" power from also supplies my office building where my tenants and I all have a lot of high-speed communications equipment and computers. Would I need to take extra precautions to keep from hearing cries of anguish every time I fire things up to mill down a hex nut?

You've been very gracious with the information so far, I feel a bit embarrassed that I keep asking for more.

Many thanks,

-Ron
 
Ron

A properly made and constructed RPC will give excellent results with little or no effects that you or the hydro company supplying you the power will notice. I would be more concerned about Hi Freq TIG Welding of Aluminium than I would of the RPC.

Small RPC's start with very little load on the system, but larger ones can. It is like starting a large motor. That is where the Soft Start Module comes in. A large RPC can start with a lot lower in rush current. With the Soft Start you can use a breaker about 2/3 to 1/2 the size as with out, but bear in mind that your total max HP rating of the RPC will be limited if you use too small a breaker.

If you have a large motor operating on a RPC, and start another one, you will notice a slight blip in the output of the RPC. CNC units need the VLS and need less possiblity of any form of spiking from "other" motors starting up so they are limited to total HP.

Like you I have an office full of sensitive electronics and I never see anything that would concern me.

Walter
 
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