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

*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.


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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