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Date: 15 Nov 2006 19:21:11
From:
Subject: What's a Good PID with a second setpoint for steaming?
I am finally installing a PID in my Silvia.
I was wondering what a good PID with a second setpoint for steaming via
a digital input switch is?
Omega? Other?
I am trying to figure out how much more money it would cost. Or if I am
better off just getting a Fuji PXR3, Since I am happy with the current
steam capabilities.

Oh and does anyone know why Washer Thermocouples any length are now $28
from TTIGlobal?





 
Date: 17 Nov 2006 18:39:26
From: jggall01
Subject: Re: What's a Good PID with a second setpoint for steaming?

medley wrote:
> Ah so you can use "ramp and soak" to steam with the Fuji PXR3. now I
> found some threads on it.
> I know many people have used the Watlow 96, I've just never heard
> anyone say they are the best choice.
> yes I am very familiar with Randy G's site.
> I am planning on getting a Thermocouple much longer than I need,
> especially because I might do "A Tail about Silvia" style install.

Keep in mind that the existing steam tstat will frustrate attempts by
the PID to control the temp if you exceed the steam tstat OFF point.
If you want the Fuji PID to fully control the boiler, you need to short
the steam tstat, even if you don't fool around with rewiring the steam
switch.

Jim



 
Date: 17 Nov 2006 18:27:30
From: medley
Subject: Re: What's a Good PID with a second setpoint for steaming?
Ah so you can use "ramp and soak" to steam with the Fuji PXR3. now I
found some threads on it.
I know many people have used the Watlow 96, I've just never heard
anyone say they are the best choice.
yes I am very familiar with Randy G's site.
I am planning on getting a Thermocouple much longer than I need,
especially because I might do "A Tail about Silvia" style install.



 
Date: 15 Nov 2006 20:24:07
From: jggall01
Subject: Re: What's a Good PID with a second setpoint for steaming?
jesse.medley@gmail.com wrote:
> I am finally installing a PID in my Silvia.
> I was wondering what a good PID with a second setpoint for steaming via
> a digital input switch is?

If you can locate a Watlow series 96 with event input before I do, that
would be a great choice ;-}

> Omega? Other?

Omega controllers? I wouldn't. Anything else from Omega? Yes,
absolutely (including washer thermocouple probes).

> I am trying to figure out how much more money it would cost. Or if I am
> better off just getting a Fuji PXR3, Since I am happy with the current
> steam capabilities.

Been lots of debate on this subject. I have the steam temp controlled
by PID on my machine, and have assisted others to do same. More
convenient since you can't "miss" the tstat limit while fiddling with
milk pitcher. Depending on your success in locating a controller,
doesn't have to cost much extra.

I'm pretty sure the Fuji can be ordered with second setpoint option,
but I'm not as familiar with that product line as some other AC
regulars who I hope will chime in.

Randy G's site (www.espressomyespresso.com) has a correct wiring
diagram showing how to do the wiring and maintain full function of the
steam switch.

>
> Oh and does anyone know why Washer Thermocouples any length are now $28
> from TTIGlobal?

No idea, but Omega still has good prices. I suggest teflon insulated,
24 AWG type T. Stay away from glass insulation and type J t/c's. Type
K is OK, but T is better for this application. Order with 48" leads if
you are doing a Murph-type install, then coil up or shorten as needed.
Don't lengthen as this can create additional junctions which give false
readings.

Jim



  
Date: 16 Nov 2006 16:40:36
From: Mud Pup
Subject: Re: What's a Good PID with a second setpoint for steaming?
jggall01 wrote:
>
> I'm pretty sure the Fuji can be ordered with second setpoint option,
> but I'm not as familiar with that product line as some other AC
> regulars who I hope will chime in.

The Fuji's second setpoint has some interesting features. If you
so choose, you can have the steam function use a "ramp and soak"
mode. With this mode you would ask the PID to raise the temperature
first to some really high value - like 400 degrees - but for only
20 seconds or so. This causes it to turn the heat on non-stop.
After the 20 seconds, it moves to the next setpoint in the ramp
and soak function which you set for your target steam temperature
for a duration of, say, 10 minutes - long, but not infinite in
case you forget to shut it off.

This configuration gets around the PID's desire to bring you to
the target steam temperature slowly. The base PXR3 has this
feature (as long as you specify it when ordering) however, if you
want to hook it up to the steam button on the Silvia, Gaggia, etc.,
then you need one with a digital input which is about $30 extra.
*The base unit won't do it.*

Other PIDs may do better in this area. Specifically, if the PXR3
had a different set of P,I,D values for the second setpoint which
could be made more aggressive, then the ramp soak function
wouldn't be necessary. (This is arguable, however, as a more aggressive
program would simply look more like a thermostat, AFAIK.)

Anyway, I can confirm it works great for a Gaggia Espresso. If
anyone wants to make the mod specifically for a Gaggia, I can
give you a minimal-change wiring diagram.


   
Date: 16 Nov 2006 10:46:51
From: Randy G.
Subject: Re: What's a Good PID with a second setpoint for steaming?
I have run a second set point PID as well as a single (brew only) set
point PID on my Silvia so have a basis of comparison (although they
were different brands). The stock steam thermostat on Silvia comes up
to brew temp so fast that using a PID to get there faster is not worth
the money (IMO). The benefit of using it on a Silvia is that you can
get the heating element to come back on faster than with a stock
thermostat- that is if you allow it to turn off. I will elaborate:

The single set point PID will display the boiler temp (well, duh!).
Using that displayed temperature it becomes an easy manner to "learn"
how the boiler reacts and to time your process so that you begin
steaming just before the thermostat clicks off. This eliminates the
wait for the temperature to drop before getting more heat (the dead
band). In my case, the PID hits 305-306 and the thermostat goes off.
It does not turn on again until it drops to about 260 (IIRC). So if I
time it so that the wand is clear of water and I begin to steam as it
rises just above 300 I get slightly more steam force for the duration
than if I let the thermostat to click open and turn off the heating
element.

If you have the second set point you eliminate the dead band. As soon
as the temp drops below the set point the heating element comes on
right away and this eliminates the need to "time" your steaming to
match the stock thermostat's behavior. The other benefit is that it
can be wired to the steam switch and the machine behaves just like a
stock Silvia except all heating functions are controlled by the PID.

Check my website as I have a complete set of wiring diagrams regarding
the Silvia and PID installation (schematic as well as diagrammatic
IIRC....

Off to try to rid my garage of the wood rat living in there! if it
gets to my green sweep stores I will spend the night out there with a
large mallet and play a real-life game of Whack-a-Mole. ;-)


Randy "here ratty, ratty, ratty" G.
http://www.EspressoMyEspresso.com


Mud Pup <mudpup@retriever.dyndns.org > wrote:
>
>jggall01 wrote:
>>
>> I'm pretty sure the Fuji can be ordered with second setpoint option,
>> but I'm not as familiar with that product line as some other AC
>> regulars who I hope will chime in.
>
>The Fuji's second setpoint has some interesting features. If you
>so choose, you can have the steam function use a "ramp and soak"
>mode. With this mode you would ask the PID to raise the temperature
>first to some really high value - like 400 degrees - but for only
>20 seconds or so. This causes it to turn the heat on non-stop.
>After the 20 seconds, it moves to the next setpoint in the ramp
>and soak function which you set for your target steam temperature
>for a duration of, say, 10 minutes - long, but not infinite in
>case you forget to shut it off.
>
>This configuration gets around the PID's desire to bring you to
>the target steam temperature slowly. The base PXR3 has this
>feature (as long as you specify it when ordering) however, if you
>want to hook it up to the steam button on the Silvia, Gaggia, etc.,
>then you need one with a digital input which is about $30 extra.
>*The base unit won't do it.*
>
>Other PIDs may do better in this area. Specifically, if the PXR3
>had a different set of P,I,D values for the second setpoint which
>could be made more aggressive, then the ramp soak function
>wouldn't be necessary. (This is arguable, however, as a more aggressive
>program would simply look more like a thermostat, AFAIK.)
>
>Anyway, I can confirm it works great for a Gaggia Espresso. If
>anyone wants to make the mod specifically for a Gaggia, I can
>give you a minimal-change wiring diagram.