Weller station gone bad--how to fix?

[Harvey Babb]

While you're at it, check one more thing! If the problem turns out to be
welded contacts on the thermostat switch, check that the MOV across the
secondary of the transformer is still good. I had one that repeatedly
welded the contacts till I replaced the MOV and has worked for 5 years
now without a problem.

Joshua G Senecal wrote:

On Fri, 19 Dec 2003, G.Beat wrote:
Wow, I didn't think that my question would generate so many responses!
Thanks everyone for your input.


The Red-Glow tells you 2 things:

1. The heater (Weller EC234) is still working (but you are shortening its
life operating in this manner - cherry red)


Well, I don't operate with it cherry red. This is the first time it's done
that--hence my knowing that something is amiss.


2. The WTCP series temperature control (which works with the "PT" tip and
the SW60 switch) is not working properly.


Recommend: Change tips. Improper tips will cause this problem.
Get a Weller PTA7 (which is the standard tip shipped with this iron).
The barrel net (BA-60 may also require replacement.


I'll take a look and see. The station came with two tips, both #7, but in
the 11-odd years I've owned the iron I've never used the second one.


I also have the Weller Tech Sheet for this model -- if you need
a copy. This has part numbers, diagrams and troubleshooting advice (shipped
with every unit new)


Actually, I would like a copy, thank you. Since I got mine at a yard sale
I don't have any documentation. Please e-mail to
jgsenecal@mapson.ucdavis.edu, removing the reversed "nospam" first.

-Josh, AE6IQ

 

[Frank Dinger]

While you're at it, check one more thing! If the problem turns out to be
welded contacts on the thermostat switch, check that the MOV across the
secondary of the transformer is still good. I had one that repeatedly
welded the contacts till I replaced the MOV and has worked for 5 years
now without a problem.
=============================

Not having such a Weller soldering iron myself ,nevertheless I am interested
in the MOV (firing) voltage against the normal operating voltage . Also , is
it DC or AC ?

Frank GM0CSZ / KN6WH

 

[G.Beat]

"Frank Dinger" <gm0cszx.xkn6wh@ntlworld.com> wrote in message
news:FyJFb.27266$R6.5667420@newsfep2-win.server.ntli.net...

While you're at it, check one more thing! If the problem turns out to be
welded contacts on the thermostat switch, check that the MOV across the
secondary of the transformer is still good. I had one that repeatedly
welded the contacts till I replaced the MOV and has worked for 5 years
now without a problem.
=============================
Not having such a Weller soldering iron myself ,nevertheless I am
interested
in the MOV (firing) voltage against the normal operating voltage . Also ,
is
it DC or AC ?

Frank GM0CSZ / KN6WH

There are no rectifiers in the WTCP series base ... all AC. Weller does
make a heater for this series that
works at 12 volts (DC) for mobile work.

gb

 

[Harvey Babb]

The MOV (Metal Oxide Varistor) is a surge supressor whose only function
is to absorb the "kick" when the mechanical thermostat opens (or
"bounces" when closing). The one in the Weller unit (if memory serves)
clamps the voltage at about 40 volts (Transformer secondary is 24 VAC).
If it isn't working properly the thermostat contacts arc and weld shut,
causing runaway overheating.

Frank Dinger wrote:

While you're at it, check one more thing! If the problem turns out to be
welded contacts on the thermostat switch, check that the MOV across the
secondary of the transformer is still good. I had one that repeatedly
welded the contacts till I replaced the MOV and has worked for 5 years
now without a problem.

=============================
Not having such a Weller soldering iron myself ,nevertheless I am interested
in the MOV (firing) voltage against the normal operating voltage . Also , is
it DC or AC ?

Frank GM0CSZ / KN6WH

 

[Frank Dinger]

"Harvey Babb" wrote :
The MOV (Metal Oxide Varistor) is a surge supressor whose only function
is to absorb the "kick" when the mechanical thermostat opens (or
"bounces" when closing). The one in the Weller unit (if memory serves)
clamps the voltage at about 40 volts (Transformer secondary is 24 VAC).
If it isn't working properly the thermostat contacts arc and weld shut,
causing runaway overheating.
==========================

Harvey , Tnx for the useful info . I was interested in the spike voltage
suppression level of the MOV, which is required since the heater element is
for AC . In the event of DC a reversely connected diode would have done the
trick .

Frank GM0CSZ / KN6WH