I want to thank all those who responded to my query regarding this issue -
this issue has indeed cropped up from time to time. I am fairly sure I know
the culprit, but rather than replacing that, we have currently
bypassed it by putting a jumper over both 208 lines going to the relay
that is part of the safety box. One advantage of jumpering over just the
relay rather than the whole box is that we continue to have the breakers
that are part of the safety box in line. I have run the console for
several hours this way, and it seems to work fine.
I am fairly certain that either the relay or the half wave rectifier
circuit that drives it are at fault in the safety box. After staring at
the schematic for a bit I finally understood how the on/off function
works, and that convinced me that the switch itself is not at fault.
In my original query I asked about replacing the relay with a DPST
switch, and I am sure that is possible, as also suggested by one of the
folks who responded. In our case, we have a breaker right at the plug
for the console, and that is a convent On/Off switch, making another
switch not really necessary.
Thank you again everyone! I really appreciate this group!
Tom Pratum
Southern Oregon Univ.
> On Aug 12, 2022, at 5:20 PM, Tom Pratum <tkp9551_at_gmail.com> wrote:
>
> Hello All-
> We have the following issue on our Avance Microbay 400 console - soon to be replaced:
>
> Came in one day and found the console shut down. The power switch did not bring it back up.
>
> After some investigation, it is seen that pushing the console power switch brings up the
> power momentarily, but then it shuts down and we need to wait about 30 seconds or so to
> try to push the button again or nothing happens at all.
>
> It has been determined that none of the circuit breakers are blown, and the one fuse in
> the relay circuit is fine. The relay circuit appears to have all of the correct static
> voltages going to it.
>
> It looks to me like the problem is either with the console switch, or with the relay circuit.
> Has anyone out there seen anything like this with their Avance console? From my perusal of
> the various Avance schematics I find, it appears that a similar safety circuit is present
> in Avance I, II and III consoles.
>
> Another related question: could the relay be replaced with a simple DPST switch? I realize a
> few of the reasons the relay circuit is there (e.g. to make sure the console stays off if the
> power goes out and comes back on), but in this case we just need to keep the console functioning
> for another 5 - 6 months ....
>
> Any ideas will be greatly appreciated as always!
>
>
>
> Tom Pratum
> Southern Oregon University
Received on Wed Aug 17 2022 - 16:08:26 MST