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Why PIDE a Bunn ES-1A (or any) espresso machine?
Why PIDE a Bunn ES-1A (or any) espresso machine?
David Mankin has installed and tested the beta version of my Bunn PID kit.
So far he's had nothing but good things to say about it - as expected since
my first Bunn has had basically the same kit installed for nearly two years
with no problems. I've also sold my first full production version of the
Bunn kit, so I suppose that means I'm now in the business of selling PID
kits for the Bunn ES-1A machines.
This all begs the question - why bother PIDing a heat exchanger machine in
the first place? After all, you're PIDing the boiler water not the HX, so
how does a PID directly benefit your coffee production? Since the Sirai
pstats have adjustable dead bands (usually set to .04 bar), the gains
enjoyed by home espresso machine users is negated. The home machines, with
their mechanical tstats, have dead bands of 30 - 40 degrees.
So if temp stability isn't the deciding factor in whether to PID or not,
what other factors are involved? First and foremost is the noise factor. If
your machine is set up near your primary seating area then you're already
keenly aware of how much noise is generated by the opening and closing of
the pstat's relays. The Sirai pstat has three sets of relays that open &
close as the boiler temperature rises and falls. This constant clicking and
clacking is distracting. Replacing the mechanical pstat with the electronic
PID solves this problem nicely.
Then there's the reliability issue. My experience has been that pstats have
the highest failure rate of all of the parts of an espresso machine. Worse
yet, the failure is not readily apparent. Pstat failure is usually caused by
a leaking diaphragm, resulting in boiler temperatures being too low. This
drop off is detrimental to good coffee production, but does not manifest
itself in a manner that causes the operator to say, "Aha, the pstat is
leaking so it needs to be replaced!".
The other issue is minor, but more apparent. We're a country that lives by
the pound and measures our temperatures by Fahrenheit degrees and converting
1.2 - 1.5 bar to temperatures mentally is taxing. Since the PID measures
actual temperatures inside the boiler there's nothing to convert. When the
display reads 257 degrees your mind recognizes that all is well and
functioning properly.
So, that's the background story on PIDing your HX equipped Bunn. Is it worth
it to you to have a quieter, more reliable espresso machine? If you're
leaning toward answering in the affirmative then check out the link to my
PID pages.
Robert (Tex) Harmon
http :// www .tinyurl,com /mb4uj - My coffee pages.
http :// www .tinyurl,com /24p7hu - PID kits for espresso machines
http :// www .tinyurl,com /2j8jur - Gaggia User's Group
http :// www .tinyurl,com /235dfr - BUG is Bunn User's Group (espresso)
David Mankin has installed and tested the beta version of my Bunn PID kit.
So far he's had nothing but good things to say about it - as expected since
my first Bunn has had basically the same kit installed for nearly two years
with no problems. I've also sold my first full production version of the
Bunn kit, so I suppose that means I'm now in the business of selling PID
kits for the Bunn ES-1A machines.
This all begs the question - why bother PIDing a heat exchanger machine in
the first place? After all, you're PIDing the boiler water not the HX, so
how does a PID directly benefit your coffee production? Since the Sirai
pstats have adjustable dead bands (usually set to .04 bar), the gains
enjoyed by home espresso machine users is negated. The home machines, with
their mechanical tstats, have dead bands of 30 - 40 degrees.
So if temp stability isn't the deciding factor in whether to PID or not,
what other factors are involved? First and foremost is the noise factor. If
your machine is set up near your primary seating area then you're already
keenly aware of how much noise is generated by the opening and closing of
the pstat's relays. The Sirai pstat has three sets of relays that open &
close as the boiler temperature rises and falls. This constant clicking and
clacking is distracting. Replacing the mechanical pstat with the electronic
PID solves this problem nicely.
Then there's the reliability issue. My experience has been that pstats have
the highest failure rate of all of the parts of an espresso machine. Worse
yet, the failure is not readily apparent. Pstat failure is usually caused by
a leaking diaphragm, resulting in boiler temperatures being too low. This
drop off is detrimental to good coffee production, but does not manifest
itself in a manner that causes the operator to say, "Aha, the pstat is
leaking so it needs to be replaced!".
The other issue is minor, but more apparent. We're a country that lives by
the pound and measures our temperatures by Fahrenheit degrees and converting
1.2 - 1.5 bar to temperatures mentally is taxing. Since the PID measures
actual temperatures inside the boiler there's nothing to convert. When the
display reads 257 degrees your mind recognizes that all is well and
functioning properly.
So, that's the background story on PIDing your HX equipped Bunn. Is it worth
it to you to have a quieter, more reliable espresso machine? If you're
leaning toward answering in the affirmative then check out the link to my
PID pages.
Robert (Tex) Harmon
http :// www .tinyurl,com /mb4uj - My coffee pages.
http :// www .tinyurl,com /24p7hu - PID kits for espresso machines
http :// www .tinyurl,com /2j8jur - Gaggia User's Group
http :// www .tinyurl,com /235dfr - BUG is Bunn User's Group (espresso)
Re: Why PIDE a Bunn ES-1A (or any) espresso machine?
"Tex" <pearland@earthlink,net > wrote in message
news:56udnf3AeLHej zVnZ2dnUVZ qPinZ2d@earthlink,com ...
snip.
>
> This all begs the question - why bother PIDing a heat exchanger machine in
> the first place? After all, you're PIDing the boiler water not the HX, so
> how does a PID directly benefit your coffee production? Since the Sirai
> pstats have adjustable dead bands (usually set to .04 bar), the gains
> enjoyed by home espresso machine users is negated. The home machines, with
> their mechanical tstats, have dead bands of 30 - 40 degrees.
I suppose it depends what you mean by "home machine". It's true the single
boiler ones usually have "click" type thermostats that operate by bimetal
action. However, the "high end" HX machines (Oscar and the various shiny
stainless steel machines) usually have "mini" Pstats by Mater , CEME and
others that if anything have a SMALLER deadband than the Sirai.
>
> So if temp stability isn't the deciding factor in whether to PID or not,
> what other factors are involved? First and foremost is the noise factor.
> If your machine is set up near your primary seating area then you're
> already keenly aware of how much noise is generated by the opening and
> closing of the pstat's relays. The Sirai pstat has three sets of relays
> that open & close as the boiler temperature rises and falls. This constant
> clicking and clacking is distracting. Replacing the mechanical pstat with
> the electronic PID solves this problem nicely.
I would say noise is not a big factor in the mini stats - they click on and
off audibly but the click is not very loud.
>
> Then there's the reliability issue. My experience has been that pstats
> have the highest failure rate of all of the parts of an espresso machine.
> Worse yet, the failure is not readily apparent. Pstat failure is usually
> caused by a leaking diaphragm, resulting in boiler temperatures being too
> low. This drop off is detrimental to good coffee production, but does not
> manifest itself in a manner that causes the operator to say, "Aha, the
> pstat is leaking so it needs to be replaced!".
Beside leaking, the ministats have nasty failure modes - they get stuck in
the "on" position and the boiler keeps heating until the safety valve pops
off. This was my #1 reason for getting rid of them in favor of PID. Also
very high reliability problems - ideally a mini pstat is supposed to be off
to the side of the boiler and connect by P-trap shaped tube which allow the
pstat to "see" the boiler pressure but to be buffered a little from the
direct heat of the steam. On my machine (Oscar) the pstat was screwed right
to a port in the top of the boiler and I was getting less than a year out of
my Pstats.
>
> The other issue is minor, but more apparent. We're a country that lives by
> the pound and measures our temperatures by Fahrenheit degrees and
> converting 1.2 - 1.5 bar to temperatures mentally is taxing. Since the PID
> measures actual temperatures inside the boiler there's nothing to convert.
> When the display reads 257 degrees your mind recognizes that all is well
> and functioning properly.
I don't buy that one. Traditionally, people controlled steam boilers by
looking at pressure gauges, whether in PSI or bar. If you have any
familiarity with working with boiler pressure gauges, then looking at a
temperature readout is more confusing than helpful. I always thought the PID
manufacturers should offer a function where the readout would be in bar -
even though the thermocouple measures temperature not presssure, if you
build a "steam table" function into the PID, it is possible to convert one
directly to the other. Actually the PID doesn't really measure temperature
directly either, it measures thermocouple voltage so it is already
performing a lookup table function.
"Tex" <pearland@earthlink,net > wrote in message
news:56udnf3AeLHej zVnZ2dnUVZ qPinZ2d@earthlink,com ...
snip.
>
> This all begs the question - why bother PIDing a heat exchanger machine in
> the first place? After all, you're PIDing the boiler water not the HX, so
> how does a PID directly benefit your coffee production? Since the Sirai
> pstats have adjustable dead bands (usually set to .04 bar), the gains
> enjoyed by home espresso machine users is negated. The home machines, with
> their mechanical tstats, have dead bands of 30 - 40 degrees.
I suppose it depends what you mean by "home machine". It's true the single
boiler ones usually have "click" type thermostats that operate by bimetal
action. However, the "high end" HX machines (Oscar and the various shiny
stainless steel machines) usually have "mini" Pstats by Mater , CEME and
others that if anything have a SMALLER deadband than the Sirai.
>
> So if temp stability isn't the deciding factor in whether to PID or not,
> what other factors are involved? First and foremost is the noise factor.
> If your machine is set up near your primary seating area then you're
> already keenly aware of how much noise is generated by the opening and
> closing of the pstat's relays. The Sirai pstat has three sets of relays
> that open & close as the boiler temperature rises and falls. This constant
> clicking and clacking is distracting. Replacing the mechanical pstat with
> the electronic PID solves this problem nicely.
I would say noise is not a big factor in the mini stats - they click on and
off audibly but the click is not very loud.
>
> Then there's the reliability issue. My experience has been that pstats
> have the highest failure rate of all of the parts of an espresso machine.
> Worse yet, the failure is not readily apparent. Pstat failure is usually
> caused by a leaking diaphragm, resulting in boiler temperatures being too
> low. This drop off is detrimental to good coffee production, but does not
> manifest itself in a manner that causes the operator to say, "Aha, the
> pstat is leaking so it needs to be replaced!".
Beside leaking, the ministats have nasty failure modes - they get stuck in
the "on" position and the boiler keeps heating until the safety valve pops
off. This was my #1 reason for getting rid of them in favor of PID. Also
very high reliability problems - ideally a mini pstat is supposed to be off
to the side of the boiler and connect by P-trap shaped tube which allow the
pstat to "see" the boiler pressure but to be buffered a little from the
direct heat of the steam. On my machine (Oscar) the pstat was screwed right
to a port in the top of the boiler and I was getting less than a year out of
my Pstats.
>
> The other issue is minor, but more apparent. We're a country that lives by
> the pound and measures our temperatures by Fahrenheit degrees and
> converting 1.2 - 1.5 bar to temperatures mentally is taxing. Since the PID
> measures actual temperatures inside the boiler there's nothing to convert.
> When the display reads 257 degrees your mind recognizes that all is well
> and functioning properly.
I don't buy that one. Traditionally, people controlled steam boilers by
looking at pressure gauges, whether in PSI or bar. If you have any
familiarity with working with boiler pressure gauges, then looking at a
temperature readout is more confusing than helpful. I always thought the PID
manufacturers should offer a function where the readout would be in bar -
even though the thermocouple measures temperature not presssure, if you
build a "steam table" function into the PID, it is possible to convert one
directly to the other. Actually the PID doesn't really measure temperature
directly either, it measures thermocouple voltage so it is already
performing a lookup table function.
Re: Why PIDE a Bunn ES-1A (or any) espresso machine?
On Jun 24, 1:42 pm, "Jack Denver" <nunuv...@netscape,net > wrote:
> "Tex" <pearl...@earthlink,net > wrote in message
>
> news:56udnf3AeLHej zVnZ2dnUVZ qPinZ2d@earthlink,com ...
> snip.
>
>
>
> > This all begs the question - why bother PIDing a heat exchanger machine in
> > the first place? After all, you're PIDing the boiler water not the HX, so
> > how does a PID directly benefit your coffee production? Since the Sirai
> > pstats have adjustable dead bands (usually set to .04 bar), the gains
> > enjoyed by home espresso machine users is negated. The home machines, with
> > their mechanical tstats, have dead bands of 30 - 40 degrees.
>
> I suppose it depends what you mean by "home machine". It's true the single
> boiler ones usually have "click" type thermostats that operate by bimetal
> action. However, the "high end" HX machines (Oscar and the various shiny
> stainless steel machines) usually have "mini" Pstats by Mater , CEME and
> others that if anything have a SMALLER deadband than the Sirai.
>
>
>
> > So if temp stability isn't the deciding factor in whether to PID or not,
> > what other factors are involved? First and foremost is the noise factor.
> > If your machine is set up near your primary seating area then you're
> > already keenly aware of how much noise is generated by the opening and
> > closing of the pstat's relays. The Sirai pstat has three sets of relays
> > that open & close as the boiler temperature rises and falls. This constant
> > clicking and clacking is distracting. Replacing the mechanical pstat with
> > the electronic PID solves this problem nicely.
>
> I would say noise is not a big factor in the mini stats - they click on and
> off audibly but the click is not very loud.
>
>
>
> > Then there's the reliability issue. My experience has been that pstats
> > have the highest failure rate of all of the parts of an espresso machine.
> > Worse yet, the failure is not readily apparent. Pstat failure is usually
> > caused by a leaking diaphragm, resulting in boiler temperatures being too
> > low. This drop off is detrimental to good coffee production, but does not
> > manifest itself in a manner that causes the operator to say, "Aha, the
> > pstat is leaking so it needs to be replaced!".
>
> Beside leaking, the ministats have nasty failure modes - they get stuck in
> the "on" position and the boiler keeps heating until the safety valve pops
> off. This was my #1 reason for getting rid of them in favor of PID. Also
> very high reliability problems - ideally a mini pstat is supposed to be off
> to the side of the boiler and connect by P-trap shaped tube which allow the
> pstat to "see" the boiler pressure but to be buffered a little from the
> direct heat of the steam. On my machine (Oscar) the pstat was screwed right
> to a port in the top of the boiler and I was getting less than a year out of
> my Pstats.
>
>
>
> > The other issue is minor, but more apparent. We're a country that lives by
> > the pound and measures our temperatures by Fahrenheit degrees and
> > converting 1.2 - 1.5 bar to temperatures mentally is taxing. Since the PID
> > measures actual temperatures inside the boiler there's nothing to convert.
> > When the display reads 257 degrees your mind recognizes that all is well
> > and functioning properly.
>
> I don't buy that one. Traditionally, people controlled steam boilers by
> looking at pressure gauges, whether in PSI or bar. If you have any
> familiarity with working with boiler pressure gauges, then looking at a
> temperature readout is more confusing than helpful. I always thought the PID
> manufacturers should offer a function where the readout would be in bar -
> even though the thermocouple measures temperature not presssure, if you
> build a "steam table" function into the PID, it is possible to convert one
> directly to the other. Actually the PID doesn't really measure temperature
> directly either, it measures thermocouple voltage so it is already
> performing a lookup table function.
Izzy! now there's an idea -- a pid with a pressure sensor.
those are already out there, pal .
LOL
On Jun 24, 1:42 pm, "Jack Denver" <nunuv...@netscape,net > wrote:
> "Tex" <pearl...@earthlink,net > wrote in message
>
> news:56udnf3AeLHej zVnZ2dnUVZ qPinZ2d@earthlink,com ...
> snip.
>
>
>
> > This all begs the question - why bother PIDing a heat exchanger machine in
> > the first place? After all, you're PIDing the boiler water not the HX, so
> > how does a PID directly benefit your coffee production? Since the Sirai
> > pstats have adjustable dead bands (usually set to .04 bar), the gains
> > enjoyed by home espresso machine users is negated. The home machines, with
> > their mechanical tstats, have dead bands of 30 - 40 degrees.
>
> I suppose it depends what you mean by "home machine". It's true the single
> boiler ones usually have "click" type thermostats that operate by bimetal
> action. However, the "high end" HX machines (Oscar and the various shiny
> stainless steel machines) usually have "mini" Pstats by Mater , CEME and
> others that if anything have a SMALLER deadband than the Sirai.
>
>
>
> > So if temp stability isn't the deciding factor in whether to PID or not,
> > what other factors are involved? First and foremost is the noise factor.
> > If your machine is set up near your primary seating area then you're
> > already keenly aware of how much noise is generated by the opening and
> > closing of the pstat's relays. The Sirai pstat has three sets of relays
> > that open & close as the boiler temperature rises and falls. This constant
> > clicking and clacking is distracting. Replacing the mechanical pstat with
> > the electronic PID solves this problem nicely.
>
> I would say noise is not a big factor in the mini stats - they click on and
> off audibly but the click is not very loud.
>
>
>
> > Then there's the reliability issue. My experience has been that pstats
> > have the highest failure rate of all of the parts of an espresso machine.
> > Worse yet, the failure is not readily apparent. Pstat failure is usually
> > caused by a leaking diaphragm, resulting in boiler temperatures being too
> > low. This drop off is detrimental to good coffee production, but does not
> > manifest itself in a manner that causes the operator to say, "Aha, the
> > pstat is leaking so it needs to be replaced!".
>
> Beside leaking, the ministats have nasty failure modes - they get stuck in
> the "on" position and the boiler keeps heating until the safety valve pops
> off. This was my #1 reason for getting rid of them in favor of PID. Also
> very high reliability problems - ideally a mini pstat is supposed to be off
> to the side of the boiler and connect by P-trap shaped tube which allow the
> pstat to "see" the boiler pressure but to be buffered a little from the
> direct heat of the steam. On my machine (Oscar) the pstat was screwed right
> to a port in the top of the boiler and I was getting less than a year out of
> my Pstats.
>
>
>
> > The other issue is minor, but more apparent. We're a country that lives by
> > the pound and measures our temperatures by Fahrenheit degrees and
> > converting 1.2 - 1.5 bar to temperatures mentally is taxing. Since the PID
> > measures actual temperatures inside the boiler there's nothing to convert.
> > When the display reads 257 degrees your mind recognizes that all is well
> > and functioning properly.
>
> I don't buy that one. Traditionally, people controlled steam boilers by
> looking at pressure gauges, whether in PSI or bar. If you have any
> familiarity with working with boiler pressure gauges, then looking at a
> temperature readout is more confusing than helpful. I always thought the PID
> manufacturers should offer a function where the readout would be in bar -
> even though the thermocouple measures temperature not presssure, if you
> build a "steam table" function into the PID, it is possible to convert one
> directly to the other. Actually the PID doesn't really measure temperature
> directly either, it measures thermocouple voltage so it is already
> performing a lookup table function.
Izzy! now there's an idea -- a pid with a pressure sensor.
those are already out there, pal .
LOL
Re: Why PID a Bunn ES-1A (or any commercial HX) espresso machine?
"Jack Denver" <nunuvyer@netscape,net > wrote in message
news:g6ydnes7cZ6er_zVnZ2dnUVZ_szinZ2d@comcast,com ...
>
> "Tex" <pearland@earthlink,net > wrote in message
> news:56udnf3AeLHej_zVnZ2dnUVZ_qPinZ2d@earthlink,com ...
> snip.
>>
>> This all begs the question - why bother PIDing a heat exchanger machine
>> in the first place? After all, you're PIDing the boiler water not the HX,
>> so how does a PID directly benefit your coffee production? Since the
>> Sirai pstats have adjustable dead bands (usually set to .04 bar), the
>> gains enjoyed by home espresso machine users is negated. The home
>> machines, with their mechanical tstats, have dead bands of 30 - 40
>> degrees.
>
> I suppose it depends what you mean by "home machine". It's true the single
> boiler ones usually have "click" type thermostats that operate by bimetal
> action. However, the "high end" HX machines (Oscar and the various shiny
> stainless steel machines) usually have "mini" Pstats by Mater , CEME and
> others that if anything have a SMALLER deadband than the Sirai.
>
My bad - I should've differentiated between home/consumer machines
(sub-$800), prosumer machines ($800 - 2500), and commercial machines
($2500+).
In this instance the home machines I'm refererring to are almost exclusively
using mechanical bimetal thermostats.
>>
>> So if temp stability isn't the deciding factor in whether to PID or not,
>> what other factors are involved? First and foremost is the noise factor.
>> If your machine is set up near your primary seating area then you're
>> already keenly aware of how much noise is generated by the opening and
>> closing of the pstat's relays. The Sirai pstat has three sets of relays
>> that open & close as the boiler temperature rises and falls. This
>> constant clicking and clacking is distracting. Replacing the mechanical
>> pstat with the electronic PID solves this problem nicely.
>
> I would say noise is not a big factor in the mini stats - they click on
> and off audibly but the click is not very loud.
>
My bad again - the original subject should have specified full-blown
commercial HX machines. These typically use a Sirai-type pstat with multiple
relay contacts.
>>
>> Then there's the reliability issue. My experience has been that pstats
>> have the highest failure rate of all of the parts of an espresso machine.
>> Worse yet, the failure is not readily apparent. Pstat failure is usually
>> caused by a leaking diaphragm, resulting in boiler temperatures being too
>> low. This drop off is detrimental to good coffee production, but does not
>> manifest itself in a manner that causes the operator to say, "Aha, the
>> pstat is leaking so it needs to be replaced!".
>
> Beside leaking, the ministats have nasty failure modes - they get stuck in
> the "on" position and the boiler keeps heating until the safety valve pops
> off. This was my #1 reason for getting rid of them in favor of PID. Also
> very high reliability problems - ideally a mini pstat is supposed to be
> off to the side of the boiler and connect by P-trap shaped tube which
> allow the pstat to "see" the boiler pressure but to be buffered a little
> from the direct heat of the steam. On my machine (Oscar) the pstat was
> screwed right to a port in the top of the boiler and I was getting less
> than a year out of my Pstats.
>
Regardless, the pstat is the most frequently replaced big-ticket item on
these machines.
>>
>> The other issue is minor, but more apparent. We're a country that lives
>> by the pound and measures our temperatures by Fahrenheit degrees and
>> converting 1.2 - 1.5 bar to temperatures mentally is taxing. Since the
>> PID measures actual temperatures inside the boiler there's nothing to
>> convert. When the display reads 257 degrees your mind recognizes that all
>> is well and functioning properly.
>
> I don't buy that one. Traditionally, people controlled steam boilers by
> looking at pressure gauges, whether in PSI or bar. If you have any
> familiarity with working with boiler pressure gauges, then looking at a
> temperature readout is more confusing than helpful. I always thought the
> PID manufacturers should offer a function where the readout would be in
> bar - even though the thermocouple measures temperature not presssure, if
> you build a "steam table" function into the PID, it is possible to convert
> one directly to the other. Actually the PID doesn't really measure
> temperature directly either, it measures thermocouple voltage so it is
> already performing a lookup table function.
>
True enough for experienced folks, but as more & more noobs are drifting
toward pstat-equipped machines I get more & more inquiries about converting
bar to psi to degrees.
--
Enjoy!
Robert (Tex) Harmon
http :// www .tinyurl,com /mb4uj - My coffee pages.
http :// www .tinyurl,com /24p7hu - PID kits for espresso machines.
http :// www .tinyurl,com /2cr3e2 - I have things for sale here.
"Jack Denver" <nunuvyer@netscape,net > wrote in message
news:g6ydnes7cZ6er_zVnZ2dnUVZ_szinZ2d@comcast,com ...
>
> "Tex" <pearland@earthlink,net > wrote in message
> news:56udnf3AeLHej_zVnZ2dnUVZ_qPinZ2d@earthlink,com ...
> snip.
>>
>> This all begs the question - why bother PIDing a heat exchanger machine
>> in the first place? After all, you're PIDing the boiler water not the HX,
>> so how does a PID directly benefit your coffee production? Since the
>> Sirai pstats have adjustable dead bands (usually set to .04 bar), the
>> gains enjoyed by home espresso machine users is negated. The home
>> machines, with their mechanical tstats, have dead bands of 30 - 40
>> degrees.
>
> I suppose it depends what you mean by "home machine". It's true the single
> boiler ones usually have "click" type thermostats that operate by bimetal
> action. However, the "high end" HX machines (Oscar and the various shiny
> stainless steel machines) usually have "mini" Pstats by Mater , CEME and
> others that if anything have a SMALLER deadband than the Sirai.
>
My bad - I should've differentiated between home/consumer machines
(sub-$800), prosumer machines ($800 - 2500), and commercial machines
($2500+).
In this instance the home machines I'm refererring to are almost exclusively
using mechanical bimetal thermostats.
>>
>> So if temp stability isn't the deciding factor in whether to PID or not,
>> what other factors are involved? First and foremost is the noise factor.
>> If your machine is set up near your primary seating area then you're
>> already keenly aware of how much noise is generated by the opening and
>> closing of the pstat's relays. The Sirai pstat has three sets of relays
>> that open & close as the boiler temperature rises and falls. This
>> constant clicking and clacking is distracting. Replacing the mechanical
>> pstat with the electronic PID solves this problem nicely.
>
> I would say noise is not a big factor in the mini stats - they click on
> and off audibly but the click is not very loud.
>
My bad again - the original subject should have specified full-blown
commercial HX machines. These typically use a Sirai-type pstat with multiple
relay contacts.
>>
>> Then there's the reliability issue. My experience has been that pstats
>> have the highest failure rate of all of the parts of an espresso machine.
>> Worse yet, the failure is not readily apparent. Pstat failure is usually
>> caused by a leaking diaphragm, resulting in boiler temperatures being too
>> low. This drop off is detrimental to good coffee production, but does not
>> manifest itself in a manner that causes the operator to say, "Aha, the
>> pstat is leaking so it needs to be replaced!".
>
> Beside leaking, the ministats have nasty failure modes - they get stuck in
> the "on" position and the boiler keeps heating until the safety valve pops
> off. This was my #1 reason for getting rid of them in favor of PID. Also
> very high reliability problems - ideally a mini pstat is supposed to be
> off to the side of the boiler and connect by P-trap shaped tube which
> allow the pstat to "see" the boiler pressure but to be buffered a little
> from the direct heat of the steam. On my machine (Oscar) the pstat was
> screwed right to a port in the top of the boiler and I was getting less
> than a year out of my Pstats.
>
Regardless, the pstat is the most frequently replaced big-ticket item on
these machines.
>>
>> The other issue is minor, but more apparent. We're a country that lives
>> by the pound and measures our temperatures by Fahrenheit degrees and
>> converting 1.2 - 1.5 bar to temperatures mentally is taxing. Since the
>> PID measures actual temperatures inside the boiler there's nothing to
>> convert. When the display reads 257 degrees your mind recognizes that all
>> is well and functioning properly.
>
> I don't buy that one. Traditionally, people controlled steam boilers by
> looking at pressure gauges, whether in PSI or bar. If you have any
> familiarity with working with boiler pressure gauges, then looking at a
> temperature readout is more confusing than helpful. I always thought the
> PID manufacturers should offer a function where the readout would be in
> bar - even though the thermocouple measures temperature not presssure, if
> you build a "steam table" function into the PID, it is possible to convert
> one directly to the other. Actually the PID doesn't really measure
> temperature directly either, it measures thermocouple voltage so it is
> already performing a lookup table function.
>
True enough for experienced folks, but as more & more noobs are drifting
toward pstat-equipped machines I get more & more inquiries about converting
bar to psi to degrees.
--
Enjoy!
Robert (Tex) Harmon
http :// www .tinyurl,com /mb4uj - My coffee pages.
http :// www .tinyurl,com /24p7hu - PID kits for espresso machines.
http :// www .tinyurl,com /2cr3e2 - I have things for sale here.
Re: Why PID a Bunn ES-1A (or any commercial HX) espresso machine?
No such conversion is needed.
(nost) hx machines already have pressure gauges! DUH!
Dave
100 HX machines modernized.
www .hitechespresso,com
No such conversion is needed.
(nost) hx machines already have pressure gauges! DUH!
Dave
100 HX machines modernized.
www .hitechespresso,com
Re: Why PIDE [sic] a Bunn ?? why indeed? SPAM
tex/drek/harmon:
I've also sold my first full production version of the
> Bunn kit, so . . .
so there are prolly 3 or 4 (orphan) Bunns out there whose owner may
want electronic controls.
LOL
Huge market!
lol!
tex/drek/harmon:
I've also sold my first full production version of the
> Bunn kit, so . . .
so there are prolly 3 or 4 (orphan) Bunns out there whose owner may
want electronic controls.
LOL
Huge market!
lol!
