RE: [CAD_CAM_EDM_DRO] Re: electrical code?

I believe the National Electric Code says that if a "nationally accepted
testing lab" (UL, CSA, TVO, etc.) lists an electrical item (especially one
that uses over 48 volts) that it is deemed acceptable from a safety
standpoint. Most jurisdictions follow this guideline and a listed machine
will not violate the local code. If a machine has not been listed (tested
for safety) by one of these labs, there is no way for the local authorities
to know if the machine design is safe to operate.

Not being listed does not mean that a machine is poorly designed, but there
is no way for the authorities to know for sure.

Regards,
Jeff
(BTW: I have both a Master Electricians license and a Professional
Engineers license and can say with certainty that most electrical machine
designs go through a number of design changes before they are deemed safe.)


-----Original Message-----
From: doug98105 [mailto:dougrasmussen@...]
Sent: Thursday, April 17, 2003 4:18 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: electrical code?

On a slightly related topic....a machine tool dealer was telling me
he is losing sales of certain CNC machines to larger companies.
These companies no longer will buy equipment unless it has UL
approval. It's an insurance issue of some kind, not sure if it's
labor & industries or the private insurance provider who is creating
the requirement.

In cases where the machine manufacturer has not sought UL approval
the potential purchaser has the option of hiring a professional
engineeer to inspect the machine and certify the wiring is properly
done.

The Haas and Fadal "starter" mini-mills are two machines the dealer
mentioned as not having UL approval. He felt sales of these will
suffer without the UL rating.






--- In CAD_CAM_EDM_DRO@yahoogroups.com, "andrewyslee"
<andrewlee@s...> wrote:

> Hi all,
>
> Thanks to this list and helpful members, I have now acquired

skills

> and knowledge and have cobbled together working stepper drivers,

etc.

> I have learned to use things like using heat shrik tubes to
> isolate exposed live wires, etc. However, while the drivers work,

I

> am not so happy with the state of the wirings, which seem a little
> messy.
>
> Now I want to aim a little higher - to make the driver a bit more
> professional, especially from the aspect of electrical and other
> safety. What are the things one would need to think about? What
> should one to to make the driver more "professional" and fullfill

all

> aspect of electrical code?
>
> BTW is there a code for electrical items like stepper driver one

can

> refer to?
>
> Many thanks
>
> Andrew

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