Model Forum / General / Models / June 2008

Put it this way bob

if i had to pay someone to do any electrical work

i would not be able to have installed any of my machines

therefor

i would not be into any sort of machining at all .

i would not be asking silly questions ..

because i simply cant afford to pay someone .

BTW .Ive had several electricians look over my past work

who commented they could not have done a better job themselves

just because i don't understand text book abbreviations for things

does not mean I'm not very safety conscious

the very fact that I'm asking questions on here means i am .

so i look to you guys to fill in the small blanks in my knowledge

after all thats what t he forum is all about ...
helping people ....i hope

all the best.markj

That's a short-term problem Bob... <G>

Regards,
Tony

Yes machine start/stop contactors are (usually) wired as NVR switches,
but some el cheapo machines are fitted with an NVR switch which
doesn't incorporate a contactor. I'm thinking of stuff aimed at the
DIY/small contractor market such as the little H-V bandsaws, some wood
planers etc.
There is I think some sort of legal requirement which these switches
are aimed to satisfy in the cheapest way possible.

Tim

On Jun 15, 11:08 am, "m...@ems-fife.co.uk" <m...@ems-fife.co.uk>
wrote:

Actually, a number of NVRs from well known makers don't have a
solenoid operated electro-mechanical contactor, but are able to be
mechanically latched when mains is present and the ON button is
pressed.  No mains releases the mechanical latch as does the overload
(overcurrent detection) mechanism and the OFF button.

The problem for anyone not familiar with motor control circuitry is
that one can find the same type of devices listed on different
stockist's catalogues and by different manufacturers as :-

Direct On-line Starters
Motor Control Switches / Starters
No-volt release switches (NVR)
Mains contactors
Motor Switches
Motor Starters
etc, etc.
with or without overload / overcurrent protection.

No doubt, someone will tell us that the correct name is none of the
above - in the same way as a "light-bulb" is really a "luminaire".

I know what I want so I can look it up in the catelogues.  In fact, I
sorted out the wiring on a mechancal "Motor Starter" for a fellow MEng
and bought an electro-mechanical type on e-bay which had over-current
protection that I removed, to make it into a simple contactor for use
with a 1-phase to 3-phase inverter.  Not so easy if you're not familar
with them.

Regards
Andy

Mark -

I've already given you all the pointers you need to figure it out. If
you can't figure it out from the information available to you, then
you are simply proving Bob M right...that there is some doubt (I would
say serious doubt) as to whether you should be doing this yourself.

Regards,
Tony