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Topic: Toggle Switch for Mazzer Revisited (69 lines)
1) From: raymanowen
Whatever you do, **do not** take the Mazzer's switch apart if kids or pets
have access to your workroom.
The way the circuit is wired, the motor cannot run if either of the limit
switches is open (Motor winding temperature or Doser fill level). If you ca=
n
start it, almost everything is OK.
The fact that it won't run when you release the switch to the *Run* positio=
n
means that the contactor cannot latch.
The contact used for latching is odd- a power contact- L3-T3 on mine.
This contactor was made with 3 power contacts (L1-T1, L2-T2 and L3-T3) for
use on 3-phase power and motor. That's normal. The same contactor would wor=
k
OK on every grinder. The latching contact (13-14) is unused- only term.14 i=
s
used as a tie-point for two wires, a white motor wire and a blue capacitor
wire. Terminal 13 is N/C. (A three phase motor wouldn't need the cap)
That's odd- Why would they use a power contact for the latch, and not use
the latch contact?
*I think maybe I see the trouble!* (Maybe mine had the problem in the past
and was fixed.) The now-unused latch contact on mine proved to be very nois=
y
when I checked it with the continuity beeper on my DVM. One open spike woul=
d
let the contactor drop out, and it sounded like hail hitting a mailbox! It
would stop almost instantly when you release it from *Start* in that case.
If your grinder has the original wiring connections, it uses 13-14 as the
latch, with two brown wires in 13, and two brown wires in 14. If this is th=
e
case, your grinder has coffee dust in the latch contacts, or it was used in
a very humid environment. The latch is noisy and the fix is easy.
Of the three ways to get it working, two are easy and one requires no parts=
:
1.)- Originally, terminal 13 had two brown wires connected, as did terminal
14. Simple fix: Jump 13 and 14. That's all. You will have to add a small
jumper- the current is miniscule.
It will just run when you turn it on and stop when you turn it off. On-Off.
*Start* will do nothing, since it will already be running.
2.)- Or, just transfer the two brown wires from 13 to the terminal L3.
The two browns on 14 go to T3, and
The Blue and White wires that were in T3 (was "floating") go to 14, which i=
s
now just a "floating" connector.
You're adding nothing, not even a jumper. Just transferring wires. It won't
run until you go to Start, so it will act totally normal.
3.)- You could just leave it as originally wired and vacuum out the
contactor or hit it with spray contact cleaner, or DeOxit terminaldeoxidize=
r.
The latter will remove oxide layers and you'll probably only find it at an
electrical supply distributor. You won't need it if the vacuum works. Fun
starts now.
Cheers -RayO, aka Opa!
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Might=
y
Wichita WurliTzer- 1976


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