My Unisaw is equipped with a magnetic stater (as were all of this
model). It has a push-button switch mounted on the front of the case
for turning it on and off. In order to get the saw to run I must hit
the on button as many as 40 or 50 times to get it going. No problem
shutting it off, only starting. I have taken the cover off the
starter (mounted in back), blown it out with compressed air, sprayed
with an electronic cleaner and done the same thing to the on-off
switch. It has not helped. This means I must have either a bad
starter or a bad on-off switch. The starter is around $200. The
on-off switch is about $100. Has anyone else had this problem? Any
ideas of what part might need replacing? There are a number of parts
within the starter which look as though they might be replaceable
without having to buy a whole new starter. Again, anyone had this
problem and found an inexpensive solution. Grizzly sells a mag.
starter for $69.00 with an integrated on-off switch. I am a bit
hesitant as I do not want to risk burning out my motor with a cheap
starter. Any ideas, suggestions appreciated.
I'll have to go look; I've got a bunch of old Delta/Rockwell starters on
a bunch of different gear--they're actually built for 3-phase but I'm
using them on single. Same box/geometry just w/ the 3-wire guts instead
of one at least at that age. Anyway, seems to me there's a push start
button inside the box as well as the remote start button--check for that
and if so, that would isolate it between switch and starter.
Is the starter in metal box of about 8x12" by 3-4" deep or thereabouts?
If so, may be same/similar...
My money would be on a set of burnt relay contacts (like burnt set of
old ignition points, in essence) if I were betting. Again, I don't
recall for absolute certain whether these were replaceable but I think
they were. Of course, parts for that old a starter may no longer be
available, I don't recall.
As for the Grainger/Dayton/Atlantique starters; they're fine. All you
have to do is size the "heater" for the proper motor current. I've got
a couple of them as well that I put on stuff that originally came w/
I have a couple of 3 ph. starters around the shop but I did not
realize they can be used with single phase. Can you give me a better
idea of what I would have to do to make a 3ph starter work on single
If the saw doesn't start up at all when you press the ON button, then you
probably need to clean up the contacts for the ON button (shut the power off
to the saw first.)
If the saw starts up, will it stay running if you hold the ON button
depressed? if so, you may need to clean the STOP button contacts or the
'holding' contacts on the motor starter.
Yes! If I keep the start button depressed the stall runs but as soon
as I take my finger off it stops. Can you give me an idea of where
are the contacts inside the starter case? They are not visible and it
does not look as they the phenolic(?) cases can be opened? I know how
to clean elec. contacts but I have to gain access to them first.
I don't know about that specific brand of motor starter, but most magnetic
starters work the same way. The ON contacts are connected in parallel with a
set of 'holding contacts' on the starter itself. You will have to follow the
two wires connected to the ON button and see where they lead to on the
magnetic contactor. When the magnetic contactor pulls in, the 'holding
contacts' basically take the place of the ON button and allow the contactor
to stay on.
AND, If you replace the switch first and end up replacing the starter to
solve the problem you will have only spent $100 too much.
If you replace the starter first and end up having to replace the switch to
solve the problem you will have spent $200 too much.
I have an elderly "Progress No1" drill press, which I bought on ebay,
which appeared to have a similar problem. Then I discovered the secret was
to make sure I pushed the button in firmly, all the way in, and pause for
a moment before letting go.
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