Re: [CAD_CAM_EDM_DRO] Re: Transformer question - ground ?

In a message dated 10/24/2006 10:04:03 P.M. Eastern Daylight Time,
dave_mucha@... writes:

I have three 1 amp (166 oz-in, NEMA-23 dbl stack) motors on a
mini-mill. I'll probably swap them out for some 250 or 300 oz-in once
I get the machine running. (AutomationDirect has 266 oz-in for $40/ea
3A each)

Each of these transformers is about as large as the 10A one I got from
MPJA (110v pri and 24V sec) so I assume it should handle about 6 amps.
Using Mariss's 60% rule for amps, means that 3 motors running at 3
amps each should require a power supply of 6 amps.


The drivers are Gecko 201a's so there is no problem with over voltage.
The bridge is rated for 200 V 10A and the caps are 100V rated.

Since I have a few of these transformers laying around, I figured I'd
use them.

Testing shows that this grey wire is infinity to everything else. the
case, the black and white input, the two pairs of outputs.

with 110VAC on the black and white, the pairs have 8 volts and 28
volts with no load and there is zero voltage between any of the
secondary wires and the grey wire.

Maybe is is just a spare wire used to hang the unit when it was dipped
or some off thing ?

Makes me feel that just tyeing it off would be best.

Dave



Dave:

So, there are no markings as to the actual size of the transformers.
Physical size is some indicator but not always an accurate one. However, if they
appear to be the approximate size of your 10 Ampere transformers, then I
should think they can deliver 6 Amperes. I fully agree, tie off that odd wire,
don't even risk connecting it. If you feel you need a positive ground to the
frame then just run a wire from the mounting hardware for the transformer to a
section of the machine chassis you know is grounded. Otherwise, just use
the secondary pairs as 8 and 28 VAC supplies.

Good luck,


Randy Abernathy
4626 Old Stilesboro Road NW
Acworth, GA 30101-4066
E-mail: cnc002@...

I furnish technical support, repair, and other related services for your
industrial woodworking machinery. My background as Senior Service Engineer for
the SCMI Group for nearly fifteen years with factory training, combines with
my extensive background in electronics, mechanics, pneumatics, electrical and
CNC machinery to offer you needed support for your machinery. Services
include but are not limited to the following:


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