Re: (ET) Small E20 fire: What is it with MOVs?]

[Chris Zach <cz alembic crystel com>]

*nod* Remember though I have an E-20. So armature reversals are 
controlled by a pair of push-pull contactors.

Still, you don't want to arc them any more than you have to, thus the 
MOVs. Actually on an E20 what you can do is flip the contactors end over 
end when arcing damages them, that way you "use up" the other set of 
contactors.

But still, it's hard. Then again one would think that the resistors 
should take the spike while you're in speeds 1-3. Then again I think I 
just floored it, and since the E20 doesn't have the centrifigual clutch 
like the E12, it just went straight to full armature current.

C



On 3/15/2011 9:01 PM, David Harvey wrote:
> I've blown off lots of MOVs on E15's some that I've hacked the controls,
> if you are in gear rolling with the control off, the field is normaly
> off too, as soon as you hit it with field it can pop MOVs and other
> things. So it's generating power with no where for it to go, then when
> the contactors close there is a big spike, if you touch it it will lift
> you, feels like a fence charger. I ended up using contactors on the
> field. These motors can put out some big power. E15's will still run
> after they pop, then next time it spikes it will vaporize the F/R relay
> points and most the relay. best way to look at the MOVs is it's a fuse.
>
>
>
>
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