Ken Fox wrote:tell your dealer in no uncertain terms that he must replace this part; it is defective.

Narwal:

I'm the one who started this thread and I agree with Ken as above. I don't know anything about the dealers in Germany, but if it helps you at all please use me as an example. Explain to your dealer that I had an identical problem (huge deadband on a new machine) and that replacing the pressurestat with a new one solved the problem. FWIW, my replacement stat came with the factory deadband set at 0.9 to 1.4 bar which is still too much variance. By adjusting the nut on top of the pressurestat one can bring down the "top end" of the pressure range. I ran mine at about 0.9 to 1.0 or 1.1 bar with nice results.

Good Luck-

Mike

Ken Fox wrote: I am in the process of replacing the Sirai in my old vibe machine with a low deadband CEME wired through a relay. You won't need to put a relay in the newer machine since I believe it already has one in the undertray electronics area.

Good luck.

ken

Hi Ken,
looking forward to your results on this one, I have a couple of juniors with Sirai pstats and would like to tighten the deadbands if possible.

BTW I understand the screw adjustment raises or lowers the boiler off point but is the boiler on point also adjustable, if not what determines it?

One of my machines turns back on at .9 and the newer (my 2000) drops down to .8 before cutting in. I thought Id wait to see your results with the CEME before replacing the membrane.

cheers
Maurice

mauricem wrote:Hi Ken,
looking forward to your results on this one, I have a couple of juniors with Sirai pstats and would like to tighten the deadbands if possible.

BTW I understand the screw adjustment raises or lowers the boiler off point but is the boiler on point also adjustable, if not what determines it?

One of my machines turns back on at .9 and the newer (my 2000) drops down to .8 before cutting in. I thought Id wait to see your results with the CEME before replacing the membrane.

cheers
Maurice

Hi Maurice,

The deadband is not adjustable on the Sirai, only the overall range, the width of which is probably never much better than 0.15 bar, and which is best with a new membrane and worst with an old calcified or stiffened one. When the total deadband (high minus low value) reaches close to 0.2bar, it is time to replace the membrane or the whole stat, depending on which version you have. So, when you turn the adjusting screw the entire range, the deadband, shifts either up or down based on which direction the screw is turned.

I have today done some basic Scace Thermofilter thermometry on my vibe Junior, with the old Sirai in place. I am going to just paste in the post I made on a.c. about this as I don't want to retype it. In the next few days I'm going to swap out the Sirai and replace it with the low deadband CEME pstat, and this data I'm pasting in here will serve as a baseline for comparison. If anyone has any suggestions for what else I might test with the Scace device before I swap pstats, please respond immediately because once I put the new pstat in, I intend to leave it in place barring some sort of unanticipated problems. Herewith what I posted earlier today on a.c.:

*************

(please note that all thermography data is reported in degrees Fahrenheit; I think this gives more precision since degrees are reported by the Fluke digital thermometer in precision of tenths of a degree, and a tenth of a degree F is less than a tenth of a degree C !!!!!!!!!!!!)

Hi,

Since I inadvertently posted most of this data an hour ago, I'm going to add
the repeat of the last, 6 shot test at the end and just post it now. I have
not had time to look this over, and in any event, it is what it is, raw
data. What is presented is second by second shot temperature measurements
using my new Scace Thermofilter device (sold by EPNW) along with a Fluke
54II datalogger. Each series of shots was separated by at least 1 hour from
subsequent shot series. In most series there was a flush, and the PF was
removed for the measured flush then reinserted in approximately 10 seconds
and measurement began. The Thermofilter was not removed in between shots.
All series except the last one (and its repeat) had 60 seconds in between
shots; the last series, as noted, had 90 seconds and this was done with a
higher pstat setting (1.10bar to 1.25 bar). The earlier series of tests
were done with a pstat setting of 1.0 to 1.15 bar, showing a deadband of
0.15 bar on the Sirai pstat, which has a nearly new membrane in it.

I've decided to start a new thread on this because all of my posts on this
could be a bit confusing since they have much of the same data. So here it
is laid out, unadulterated Scace Thermofilter data on a 9 year old
unmodified Cimbali Jr. S Pourover, with thermography obtained as described.
To me, the interesting part will be to compare this, with what I can get
after installing the low deadband pstat later on in the week. Then we can
see how much impact reduced boiler temperature hysteresis has, with
comparison to these measurements, in a setup that is much easier to
accomplish than installing a PID. We will hopefully see if there is a less
invasive way to improve temperature control on a commercial 1 group Hex
machine without having to do more than swap out a pstat. If you have any
suggestions for must do baseline testing before I swap the pstats, please
let me know; I think the surgery will be done in the next couple of days
when I have time, after which a low deadband CEME pstat will reside where
the Sirai now lives.

I hope the additional data contained in this post will address questions
raised by a
number of you about different issues. I'm going to try to post the data in
a way that it can be compared, heaven help me. I will leave in the earlier
data and paste in new data:


>
> TEST SERIES #1, with 130ml Flush pre test, Shot #1:
>
> 186.1F 188.3F 190.6F (WBC would start recording here) 196.3F 197.9F
> 198.1F 197.9F 197.3F 196.9F 196.5F 196.2F 195.9F 195.7F 195.6F 195.4F
> 195.3F 195.1F 195.1F 194.9F 194.7F 194.5F 194.5F 194.3F 193.7F 193.4F (end
> of first shot)
>
> TEST SERIES #1, with 130ml Flush pre test, Shot #2:
>
> 189.1F 189.3F 190.5F (WBC would start recording here) 193.5F 195.1F 195.3F
> 195.5F 195.3F 194.9F 194.7F 194.5F 194.3F 194.2F 194.1F 194.0F 193.9F
> 193.8F 193.8F 193.7F 193.7F 193.7F 193.7F 193.6F 193.5F 193.4F 193.3F
> 193.3F 193.2F 193.1F 193.0F 192.9F 192.8F 192.2F
>
> TEST SERIES #1, with 130ml Flush pre test, Shot #3:
>
> 186.8F 187.4F 189.5F (WBC would start recording here) 192.3F 193.2F 194.1F
> 194.1F 193.9F 193.7F 193.5F 193.3F 193.3F 193.2F 193.1F 193.1F 193.1F
> 193.1F 193.1F 193.1F 193.1F 193.1F 193.1F 193.1F 193.1F 193.1F 193.1F
> 193.1F 193.1F 193.1F 193.0F

Here is a repeat of the TEST SERIES #1, with 130ml Flush pre test, for
evaluation of consistency:

TEST SERIES #1, REPEATED, with 130ml Flush pre test, Shot #1

183.7F184.9F 191.5F (WBC would start recording here) 192.2F 195.5F 199.3F
200.0F 200.1F 199.9F 199.3F 199.0F 198.7F 198.1F 197.8F 197.7F 197.5F 197.3F
197.2F 197.1F 197.0F 196.9F 196.8F 196.7F 196.6F 196.5F 196.4F 196.3F 196.1F
196.0F 195.9F


TEST SERIES #1, REPEATED, with 130ml Flush pre test, Shot #2

191.3F 191.4F 192.7F (WBC would start recording here) 195.7F 197.0F 197.1F
197.0F 196.6F 196.2F 195.8F 195.5F 195.3F 195.1F 195.1F 195.1F 195.0F 194.9F
194.9F 194.8F 194.8F 194.7F 194.7F 194.7F 194.6F 194.6F 194.6F 194.5F 194.5F
194.5F 194.5F


TEST SERIES #1, REPEATED, with 130ml Flush pre test, Shot #3

189.7F 190.3F 191.0F (WBC would start recording here) 194.3F 196.1F 196.7F
196.5F 196.1F 195.7F 195.5F 195.2F 195.0F 194.9F 194.7F 194.7F 194.6F 194.6F
194.6F 194.5F 194.6F 194.5F 194.5F 194.6F 194.6F 194.5F 194.5F 194.5F 194.5F
194.5F 194.4F


>
> TEST SERIES #2, WITHOUT ANY COOLING FLUSH, Shot #1:
>
> 185.1F 201.2 204.7 (WBC would start recording here) 206.5 207.2F 206.5
> 205.9 205.2F 204.5 203.8 203.6F 203.3F 203.2F 203.2F 203.2F 203.1F 203.1F
> 203.1F 203.0F 203.0F 202.9F 202.9F 202.7F 202.7F 202.7F 202.6F 202.5F
> 202.4F 202.3F 202.2F
>
> TEST SERIES #2, WITHOUT ANY COOLING FLUSH, Shot #2:
>
> 194.7F 200.0F 201.2F (WBC would start recording here) 203.5F 204.1F 203.9F
> 202.9F 202.3F 202.0F 201.3F 201.1F 200.9F 200.7F 200.5F 200.3F 200.2F
> 200.1F 200.0F 199.9F 199.8F 199.7F 199.7F 199.6F 199.5F 199.4F 199.3F
> 199.3F 199.2F 199.1F 199.1F
>
> TEST SERIES #2, WITHOUT ANY COOLING FLUSH, Shot #3
>
> 193.9F 194.4F 196.6F (WBC would start recording here) 198.9F 200.7F 201.1F
> 200.9F 200.3F 199.6F 199.1F 198.6F 198.4F 198.1F 197.9F 197.8F 197.7F
> 197.5F 197.5F 197.4F 197.3F 197.3F 197.3F 197.1F 197.1F 197.0F 196.9F
> 196.9F 196.7F 196.7F 196.5F

I have not repeated the non-flush tests

>
> After seeing these results I decided to repeat the flush test with a 150ml
> flush rather than my previous standard 130ml flush
>
> TEST SERIES #3, with 150ml Flush pre test, Shot #1:
>
> 176.3F 180.7F 190.7F (WBC would start recording here) 193.6F 194.6F 194.8F
> 194.7F 194.3F 193.8F 193.5F 193.3F 192.9F 192.7F 192.5F 192.3F 192.1F
> 191.9F 191.7F 191.5F 191.3F 191.2F 191.0F 190.9F 190.7F 190.5F 190.3F
> 190.2F 190.0F 189.9F 189.8F
>
> TEST SERIES #3, with 150ml Flush pre test, Shot #2:
>
> 182.1F 186.2F 188.8F (WBC would start recording here) 191.2F 191.7F 191.6F
> 190.9F 190.3F 189.9F 189.5F 189.3F 189.2F 189.1F 189.1F 189.1F 189.1F
> 189.1F 189.0F 189.0F 189.0F 188.9F 188.9F 188.9F 189.0F 189.0F 188.9F
> 188.9F 188.9F 188.9F 188.9F
>
> TEST SERIES #3, with 150ml Flush pre test, Shot #3:
>
> 183.5F 187.3F 189.0F (WBC would start recording here) 189.6F 189.7F 189.6F
> 189.5F 189.4F 189.3F 189.3F 189.3F 189.3F 189.4F 189.4F 189.5F 189.5F
> 189.5F 189.6F 189.7F 189.7F 189.8F 189.9F 189.9F 189.9F 189.9F 189.9F
> 189.8F 189.8F 189.7F 189.7F

This was not repeated

OK, now for some new data:

TEST SERIES #4, with 140ml Flush pre test, Shot #1:

180.06F 181.1F 192.1F (WBC would start recording here) 193.9 196.1F 197.3F
197.4F 197.3F 197.0F 196.3F 195.7F 195.5F 195.1F 194.8F 194.5F 194.4F 194.2F
194.1F 193.9F 193.7F 193.7F 193.5F 193.5F 193.3F 193.3F 193.1F 193.0F 192.9F
192.8F 192.7F

TEST SERIES #4, with 140ml Flush pre test, Shot #2

186.1F 190.7F 193.1F (WBC would start recording here) 195.4F 196.0F 196.0F
195.3F 194.6F 194.3F 193.9F 193.5F 193.3F 193.1F 193.0F 192.9F 192.9F 192.8F
192.7F 192.7F 192.7F 192.7F 192.7F 192.7F 192.7F 192.7F 192.7F 192.6F 192.6F
192.5F 192.5F

TEST SERIES #4, with 140ml Flush pre test, Shot #3

187.3F 190.5F 192.7F (WBC would start recording here) 195.1F 195.8F 196.0F
195.8F 195.1F 194.9F 194.6F 194.3F 194.1F 193.9F 193.7F 193.6F 193.5F 193.5F
193.5F 193.4F 193.4F 193.3F 193.4F 193.4F 193.4F 193.4F 193.3F 193.3F 193.3F
193.3F 193.3F

After more than an hour in between, this test was repeated:


TEST SERIES #4, REPEATED, with 140ml Flush pre test, Shot #1

179.9F 191.2F 194.9F (WBC would start recording here) 195.5F 197.8F 199.6F
199.8F 199.6F 198.5F 197.9F 197.3F 197.0F 196.7F 196.4F 196.2F 196.0F 195.8F
195.7F 195.6F 195.5F 195.3F 195.2F 195.1F 194.9F 194.9F 194.8F 194.7F 194.5F
194.5F 194.3F

TEST SERIES #4, REPEATED, with 140ml Flush pre test, Shot #2

188.9F 190.0F 193.1F (WBC would start recording here) 194.2F 194.5F 194.4F
194.1F 193.9F 193.7F 193.6F 193.5F 193.5F 193.5F 193.5F 193.4F 193.4F 193.4F
193.5F 193.5F 193.5F 193.5F 193.5F 193.5F 193.5F 193.5F 193.5F 193.5F 193.5F
193.5F 193.5F

TEST SERIES #4, REPEATED, with 140ml Flush pre test, Shot #3

188.6F 189.2F 191.6F (WBC would start recording here) 195.1F 195.8F 195.9F
195.7F 195.0F 194.7F 194.4F 194.1F 194.0F 193.8F 193.8F 193.8F 193.9F 193.8F
193.8F 193.7F 193.7F 193.7F 193.7F 193.7F 193.7F 193.8F 193.8F 193.7F 193.7F
193.6F 193.5F

TEST SERIES #5, with 100ml Flush pre test, Shot #1

180.9F 186.0F 189.6F (WBC starts recording here) 193.7F 196.7F 199.1F 199.9F
200.1F 200.1F 199.9F 199.5F 199.2F 198.8F 198.5F 198.3F 198.1F 197.9F 197.8F
197.7F 197.6F 197.5F 197.4F 197.3F 197.2F 197.1F 196.9F 196.8F 196.7F 196.6F
196.4F

TEST SERIES #5, with 100ml Flush pre test, Shot #2

191.5F 191.5F 192.2F (WBC starts recording here) 194.5F 196.2F 197.5F 197.5F
197.4F 197.0F 196.6F 196.2F 195.9F 195.7F 195.6F 195.5F 195.5F 195.4F 195.4F
195.3F 195.3F 195.2F 195.2F 195.1F 195.0F 194.9F 194.9F 194.9F 194.8F 194.7F
194.7F

TEST SERIES #5, with 100ml Flush pre test, Shot #3

189.9F 190.5F 191.2F (WBC starts recording here) 193.7F 195.3F 196.3F 196.5F
196.3F 196.1F 195.7F 195.5F 195.3F 195.1F 194.9F 194.8F 194.7F 194.7F 194.6F
194.5F 194.5F 194.5F 194.5F 194.5F 194.4F 194.4F 194.4F 194.3F 194.3F 194.3F
194.2F


TEST SERIES #5, REPEATED, with 100ml Flush pre test, Shot #1

179.5F 183.2F 190.9F (WBC starts recording here) 191.8F 196.3F 199.6F 200.0F
200.1F 200.1F 199.7F 199.5F 199.1F 198.9F 198.6F 198.4F 198.2F 198.1F 197.9F
197.8F 197.7F 197.5F 197.5F 197.4F 197.3F 197.2F 197.1F 197.1F 196.9F 196.8F
196.7F

TEST SERIES #5, REPEATED, with 100ml Flush pre test, Shot #2

191.5F 191.5F 192.7F (WBC starts recording here) 194.8F 197.1F 197.7F 197.9F
197.6F 197.3F 196.7F 196.5F 196.2F 196.0F 195.9F 195.8F 195.7F 195.7F 195.6F
195.5F 195.5F 195.4F 195.3F 195.3F 195.3F 195.1F 195.1F 195.1F 195.1F 194.9F
194.9

TEST SERIES #5, REPEATED, with 100ml Flush pre test, Shot #3

189.3F 190.0F 193.1F (WBC starts recording here) 195.5F 197.1F 197.4F 197.5F
197.1F 196.5F 196.1F 195.7F 195.5F 195.2F 195.1F 194.9F 194.9F 194.8F 194.7F
194.6F 194.5F 194.5F 194.5F 194.5F 194.5F 194.5F 194.5F 194.5F 194.4F 194.4F
194.4F


Then I bumped up the pstat as far as I could comfortably go on the 9 year
old Sirai (with nearly new pstat membrane) to cycling between 1.10 and 1.25
bar; beyond that I am afraid I'll tear the thing off it's mounting, the way
it is acting! I also did two things suggested by Jim Schulman; I increased
the intershot interval to 90 seconds, and also ran a total of 6 shots rather
than 3.

TEST SERIES #6, with higher pstat setting and with 130ml Flush pre test,
Shot #1

185.4F 192.8F 195.7F (WBC starts recording here) 197.5F 199.1F 201.5F 202.1F
202.1F 201.9F 201.3F 200.7F 200.1F 199.7F 199.4F 199.1F 198.9F 198.7F 198.5F
198.3F 198.1F 198.1F 197.9F 197.7F 197.6F 197.5F 197.5F 197.3F 197.3F 197.2F
197.1F


TEST SERIES #6, with higher pstat setting and with 130ml Flush pre test,
Shot #2

190.1F 190.1F 194.4F (WBC starts recording here) 197.3F 200.1F 200.9F 201.0F
200.7F 200.0F 199.3F 198.9F 198.6F 198.3F 198.2F 198.1F 198.1F 198.0F 198.0F
197.9F 197.9F 198.0F 197.9F 197.9F 197.9F 197.9F 197.9F 197.9F 197.9F 197.8F
197.8F


TEST SERIES #6, with higher pstat setting and with 130ml Flush pre test,
Shot #3

190.9F 190.9F 192.8F (WBC starts recording here) 196.5F 199.3F 199.9F 199.9F
199.2F 198.9F 198.5F 198.3F 198.2F 198.1F 198.1F 198.1F 198.1F 198.2F 198.2F
198.3F 198.3F 198.3F 198.3F 198.3F 198.3F 198.3F 198.3F 198.2F 198.2F 198.1F
198.1F


TEST SERIES #6, with higher pstat setting and with 130ml Flush pre test,
Shot #4

190.3F 190.3F 194.7F (WBC starts recording here) 197.2F 199.6F 200.6F 200.7F
200.6F 200.2F 199.7F 199.3F 199.1F 198.9F 198.8F 198.7F 198.7F 198.7F 198.7F
198.8F 198.7F 198.7F 198.7F 198.7F 198.7F 198.7F 198.7F 198.7F 198.7F 198.7F
198.6F


TEST SERIES #6, with higher pstat setting and with 130ml Flush pre test,
Shot #5

189.1F 191.8F 197.3F (WBC starts recording here) 200.1F 202.4F 203.0F 202.8F
201.7F 201.1F 200.5F 200.1F 199.9F 199.6F 199.4F 199.3F 199.2F 199.1F 199.1F
199.2F 199.2F 199.1F 199.1F 199.1F 199.1F 199.1F 199.1F 199.1F 199.1F 199.0F
199.0F


TEST SERIES #6, with higher pstat setting and with 130ml Flush pre test,
Shot #6

189.4F 193.9F 199.5F (WBC starts recording here) 201.3F 203.4F 203.5F 202.9F
202.2F 201.6F 200.9F 200.7F 200.4F 200.1F 199.9F 199.8F 199.7F 199.6F 199.5F
199.5F 199.4F 199.4F 199.4F 199.4F 199.3F 199.3F 199.3F 199.4F 199.4F 199.4F
199.4F 199.4F



TEST SERIES #6, REPEATED, 90 seconds in between shots, with higher pstat
setting and 130ml Flush pre test, shot #1

176.1F 190.6F 193.7F (WBC starts recording here) 194.9F 198.9F 200.5F 201.1F
201.1F 200.9F 200.5F 200.1F 199.7F 199.4F 199.1F 198.9F 198.7F 198.6F 198.5F
198.3F 198.2F 198.1F 197.9F 197.8F
197.7F 197.6F 197.5F 197.4F 197.3F 197.3F 197.1F


TEST SERIES #6, REPEATED, with higher pstat setting and 130ml Flush pre
test, shot #2

191.9F 192.0F 194.5F (WBC starts recording here) 196.7F 198.8F 199.4F 199.5F
199.3F 198.6F 198.3F 197.9F 197.5F 197.3F 197.1F 197.1F 197.0F 196.9F 196.9F
196.9F 196.9F 196.9F 196.9F 196.9F 197.0F 197.0F 197.0F 197.0F 196.9F 196.9F
196.9F


TEST SERIES #6, REPEATED, with higher pstat setting and 130ml Flush pre
test, shot #3

188.9F 190.3F 197.7F (WBC starts recording here) 199.9F 201.8F 201.9F 201.1F
200.5F 199.9F 199.3F 198.8F 198.5F 198.3F 198.1F 198.0F 197.9F 197.9F 197.9F
197.8F 197.7F 197.7F 197.7F 197.7F 197.6F 197.5F 197.5F 197.5F 197.5F 197.5F
197.5F


TEST SERIES #6, REPEATED, with higher pstat setting and 130ml Flush pre
test, shot #4

188.3F 195.1F 197.3F (WBC starts recording here) 199.7F 201.9F 202.0F 201.8F
200.7F 200.1F 199.7F 199.1F 198.9F 198.7F 198.7F 198.6F 198.5F 198.5F 198.4F
198.3F 198.3F 198.3F 198.3F 198.3F 198.3F 198.3F 198.2F 198.2F 198.2F 198.2F
198.1F


TEST SERIES #6, REPEATED, with higher pstat setting and 130ml Flush pre
test, shot #5

188.9F 193.9F 198.7F 200.7F 202.9F 203.3F 202.6F 201.6F 200.9F 200.2F 199.7F
199.4F 199.2F 199.1F 199.0F 198.9F 198.9F 198.9F 198.8F 198.8F 198.8F 198.8F
198.8F 198.8F 198.7F 198.7F 198.7F 198.6F 198.6F 198.6F 198.5F 198.5F 198.4F


TEST SERIES #6, REPEATED, with higher pstat setting and 130ml Flush pre
test, shot #6

188.9F 190.6F 199.4F 201.1F 203.4F 203.6F 203.3F 202.2F 201.3F 200.6F 200.3F
200.0F 199.8F 199.7F 199.5F 199.4F 199.3F 199.3F 199.3F 199.3F 199.3F 199.2F
199.2F 199.2F 199.1F 199.1F 199.1F 199.0F 198.9F 198.9F 198.9F 198.8F 198.7F

OK, that is it for now!

ken

Guys, first post on H-B

GRB and myself recently set up identical Pstat/PRV/solenoid controls on our incoming water lines for our machines. The pstat is used to monitor incoming water pressure and deactive the machine pump in case the water line is accidentally turned off or the incoming water pressure drops out.

After reading all about pstats I went back and had a look at what we have used.

The pstat we used is an MPL 800. It has a removable spring (supplied with 4 springs) the weakest of which is adjustable range from 0.69 to 2.76 bar. The literature says it has a hysterysis but does not say how much - I guess I could try to measure it. The down side is the temperature rating of only 85oC for the standard version probably because it utilizes a polyurethane diaphragm although it does say it can be ordered with a telfon diaphragm and corresponding increase in operating temp. Does anyone know about these and what the pitfalls might be?

MPL also make a zero deadband pstat (model 500) but it looks much flimsier to me than the 800.

Cheers
Bob

mauricem wrote:Hi Ken,
looking forward to your results on this one, I have a couple of juniors with Sirai pstats and would like to tighten the deadbands if possible.

BTW I understand the screw adjustment raises or lowers the boiler off point but is the boiler on point also adjustable, if not what determines it?

One of my machines turns back on at .9 and the newer (my 2000) drops down to .8 before cutting in. I thought Id wait to see your results with the CEME before replacing the membrane.

cheers
Maurice

Hi,

I was not able to make either of two CEME "low deadband" pstats work properly or reliably on my Cimbali Jr. Vibe pourover. I have therefore removed them and the Sirai is going back in. I will later PID the machine. I would not bother with changing out a Sirai for the CEME and I doubt it will produce better results for you than what you have in the machine right now.

ken

Ken Fox wrote:Hi,

I was not able to make either of two CEME "low deadband" pstats work properly or reliably on my Cimbali Jr. Vibe pourover. I have therefore removed them and the Sirai is going back in. I will later PID the machine. I would not bother with changing out a Sirai for the CEME and I doubt it will produce better results for you than what you have in the machine right now.

ken

Can you perhaps enlighten us as to what the problems were?

BobL wrote:Can you perhaps enlighten us as to what the problems were?

I never did wire the CEME through a relay; the amperage draw through the CEME with the North American Junior's heating element is either within or just slightly over the rated capacity. After discussion of this with a couple of people including Jim Schulman who really understands the electrical ramifications of this, the use of full current through it might shorten the life of the switch but would not impact its deadband or pstat functioning, so long as the switch was still working (it was). I decided that I'd put a relay in there later if the first CEME burned out prematurely, rather than go to the trouble with that at the beginning. I wanted to see if the thing would work, first.

There are two adjustments that can be made on these CEME pstats; a red plastic thing covers a hole in the middle of the top that has the adjustment screw for the pstat setting, and adjacent to that is a smaller screw for adjusting the deadband. Both of the stats, out of the wrapper, appear to have been set for something like 2+ bar! I had to let steam off the boiler and turn the machine off several times, then I kept adjusting the main screw down until I got into a usable range. What I observed was a deadband of approximately 0.2 bar on the FPG. So, then I fiddled around with the deadband adjusting screw and no matter what I did, other than when it was set with the 0.2bar deadband, the behavior was very erratic. It seemed like I had 2 choices; either a deadband of 0.05bar for 3 or 4 cycles followed by a cycle with a 0.25 bar deadband, which would repeat ad infinitum, or the original 0.2bar deadband. I played around with the main setting screw as well, trying to come up with a setting, any setting, that would give a reproducible deadband of 0.1bar or less. I never found such a setting with either pstat that was consistent.

After many hours with a flashlight hovering over this pstat and changing the set screw settings, I came to the conclusion that this pstat will not produce the results I was seeking on my Cimbali Junior. I can't extrapolate beyond that conclusion.

The funny thing is that after I took out the CEME and cleaned up the Sirai's membrane (the membrane was fairly new and didn't really need the cleaning), I decided to change the contacts over to the 2nd set from the first, with which the machine had always operated. Now, I have a deadband of 0.11 bar, which is better than I can recall ever having with that machine. So, I got my low deadband pstat, just it wasn't the CEME, it was what I had originally!

ken

Thanks for the detailed response,

How are you reading 0.11 bar deadband? It's the 0.01 bar bit I'm interested in.

After all this talk of deadband I noticed the deadband on my junior is now ~0.25 - which is more than when I got it new last year when it was ~0.15. Would you recommend a clean or replacement at this stage?

BTW I modded the drain on the junior along the lines you suggested on my review on CG. I stumbled across a tough little polypropylene box that fits snugly in the base of the junior. I added a 1/2" right angle spigot and it works great. Thanks for the tip.

Bob

BobL wrote:Thanks for the detailed response,

How are you reading 0.11 bar deadband? It's the 0.01 bar bit I'm interested in.

After all this talk of deadband I noticed the deadband on my junior is now ~0.25 - which is more than when I got it new last year when it was ~0.15. Would you recommend a clean or replacement at this stage?

BTW I modded the drain on the junior along the lines you suggested on my review on CG. I stumbled across a tough little polypropylene box that fits snugly in the base of the junior. I added a 1/2" right angle spigot and it works great. Thanks for the tip.

Bob

I was reading this on the front panel gauge. Later, in the process of doing some Scace Thermofilter testing, I bumped up the pstat pressure and the deadband returned back to around 0.15 bar. As to how I was reading it, the older Junior has a completely different layout on the FPG than the newer model and I find it easier to read, but it is hard to know whether one can really read 0.11 vs., say, 0.12

I've been doing a LOT of Scace thermofilter testing and I'm finding some major discrepancies between the front panel gauge and brew temperatures. The rotary machine is PID'd and in order to have a more or less similar average brew temperature of about 200F, it appears that the rotary's FPG will read around 0.77 bar (constantly as there is very little hysteresis) and the vibe machine will fluctuate on the pstat between 1.2 and 1.35 bar (the average between them therefore being roughly 1.275). The boiler temperature in the rotary machine, as reported by the PID, is 236F at the moment.

Clearly, this does not pass the sniff test! The FPG on the rotary is not consistent with a temperature that is 24 degrees F above the boiling point at sea level and hence the gauge should be reading well in excess of 1 bar. With a machine under PID control the FPG is about as useful as tits on a bull, but I think I need to pull it and take it apart, or replace it. I do have a spare FPG so I might replace it for fun.

Getting back to your pstat, I have had a very similar experience now TWICE with the Cimbali OEM microswitched pstat, which I regard as a total POS. I had it replaced under warranty close to the end of the first year of ownership; the new one could not do better than a 0.175bar deadband but this was better than what had become of the first one which went to 0.25bar after less than a year. I recently checked the replacement one and on the FPG it maintained a deadband of 0.25bar. The one caveat is that I no longer trust my FPG so I'd want to confirm this before I was convinced it was truly that far out of whack.

If you do replace it, I'd put in one of the cheap Maters; there is no point in paying beaucoup bucks for the Cimbali one which I think is poor quality product. On the other hand, you could consider bypassing the whole problem by just PID'ing your machine as I did. I will be posting some temperature curves from the Cimbali after I have done some more Thermofilter work. I think it will show some interesting effects from the PID, for whatever reason.

ken

I know this is a really old thread but I have been searching pstat threads and wanted to post this.
The original Cimbali pstat stuck closed and after searching threads and suppliers for replacement parts decided it would be better to replace instead of repair. I finally decided on a Sirai but was worried about the reported wide deadband.
But
I am very surprised to report mine has an extremely small dead-band. It seems to be around .02 bar not .2 bar that I read about.
The front panel gauge barely moves. The heating element cycles off for about 30 sec and then on for about 10 sec. I insulated the boiler so it does hold heat better than stock.

Has anyone had similar experience?

Steve