Direct wiring DRO to lathe?

BFHammer

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I am planning the installation of a DRO (Sino SDS6-2V) on my lathe (PM1236). The literature indicates that the input voltage is 85V-250V and it appears that the power supply is internal (i.e. no black box plug).

Any reason why I shouldn't be able to direct wire to the lathe. I have seen this mentioned on other threads but wondered if there are any considerations that I should be aware of.

Thanks in advance for any input.

Mark

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I have my DRO hardwired into my lathe control box running 240VAC. The only concern is that the lathe might be on a 30A or bigger breaker, the electrical cord gauge is usually rated for much lower current, so the wire could potentially burn up if there was a short in the DRO unit. In most control systems, there is usually a breaker or a fuse inline provide ancillary power to other machine equipment. II will often use a supplemental breaker or DIN mounted/board mounted fuse holder for branch circuits at the machine.

If I recall the PM1236 does have two double breakers in the control box, I would pull DRO power off the smaller amperage rated one.
 
I believe the PM-1236 has a double breaker for the 220vac and a single for the 24vac.

If you brought in a neutral line with your hookup wire you can tap one leg of the 220vac and the neutral to power the DRO. If you only brought in a 3-wire 220vac (no neutral) then use both legs of the 220vac. In either case, as mksj said, install a separate fuse(s) or breaker(s). I have a 3 amp breaker on mine.
 
This may be a dumb question, but since I don't have a neutral could I simply put one 3amp breaker between the 220v tap from the lathe - something like this?

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That would work, but normally you want to break both lines on a 220V circuit. A 2 pole breaker would be the best.
 
So locate my taps, install one of these and i should be good to go?
Would 14ga wire be appropriate?
Thanks for your patience with the basic questions - I'm learning!:mechanic:

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14ga would be perfect. Looks like you're good to go. :encourage:
 
Circuit breakers often don't react fast enough to protect solid state circuits- there's probably a fuse in your DRO but you can certainly add a breaker outside too
if only as an additional master switch.
Mark S.
 
I posted in this thread earlier asking a question but I deleted cause I was wrong about what I posted.

Originally I thought I had my DROs wired directly to the input line which is on a 30A breaker. On my PM1236 there are 2 breakers, a 15A for 220V & a 2A for 24V. I have the DRO wired to the 15A breaker. I have to check my mill but I'm sure I did it the same way.

Both of my DROs have fuses on the back. So that 220V 15A breaker probably won't protect the DRO's power cord from burning if it got shorted but I don't see how that could happen. The cords are cut to length, probably only 1-1.5ft long & not exposed to any possible physical damage. Should I still be concerned about installing a dedicated breaker like talked about in this thread?
 
I tapped off my control transformer and mounted a fuse block for a fast blow fuse, then cut a hole for a handybox wired to it. With a proper cover, it looks like it belongs there. I just have to remember it's low amperage capacity and only can run the DRO. Can't use it for any high current items. The transformer has a 220 VAC input, as well as a 110 VAC input, and it was unused on my machine (well this one anyway) so I decided it made sense to use it for the low power Mit DRO. And of course, it is chassis grounded, and the DRO has a 3 prong grounded cord.
 
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