# Pid on new hx machines



## Mrboots2u (May 10, 2013)

So

are they accurate / worthwhile or just a flashy light for people to marvel on the HX machine ( I realise it is more effective on a dual boiler )

I ask as rocket are now putting pids on their HX machines and it looks like the new lever being discussed may have one .

So I throw myself at the mercy of wealth of knowledge on here to explain to me in simple terms

Why go from pstat to pid on these machines , would a pid be able to accurately alter or measure the temperate of the water at the group effectively ?

cheers


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## nickso (Feb 21, 2014)

PID on hx machines only control the boiler temperature directly. The main advantages seem to be a more easy adjusment of the boiler water temperature, the lack of a deadband (or a very small one), and possibly a way to "know" what temperature you have in the group based on a chart the producer gives you (that is if the pid doesn't already display an approx. group temperature). I was considering attaching a pid to my sanremo...it is cheap and it may be fun to do so...


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## Mrboots2u (May 10, 2013)

Anyone else care to commentDavecuk?


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## tribs (Feb 21, 2012)

Maybe it's now a cheaper and more reliable alternative to a pstat, as well as doing the job better.


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## Mrboots2u (May 10, 2013)

Don't know tribs looking for answers


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## DavecUK (Aug 6, 2013)

Mrboots2u said:


> Anyone else care to commentDavecuk?


Ah, just saw this....If the HX has got a PID already then fine, if it hasn't don't bother fitting one. The PIDs used are single loop Gicar PIDs, that can't be made to act as a proportional or straight on/off...they have PID'ness thrust upon them whether you like it or not and regardless of the settings you set. it's why I made them use a dual loop PID with a "Band Function" on the Verona, to try and get back to a more pressurestat type respons on the steam boiler. To give an example, the current duetto heating element only runs at about 70% of it's capacity as it nears the setpoint, it trims down the power...this is exactly what you don't want and makes it not as good a steamer as the Verona. In fact (sadly) a modern Duetto is not as good a steamer as my Duetto number 0001

There are 3 main pressurestat configurations:


Mater XP110 or CEME switching 10-12 amps, not great but they will do it and it is within spec of the pressurstats (however shorter pressurstat contact life)

as above, but switching an SSR or Mechanical relay (long pressurestat life, with good water 7-10+ years for XP110) I don't like CEME (as used in Isomac) or Parker stats (as used in Expobar)

Big Sirai Commercial stat (same sort of mechanism, but big relay within stat body (long life as above, but bloody noisy, good stat though).


Number 2 with an XP110 switching an SSR is my preferred configuration. Cheap to replace the Mater under £20 and a 5 minute job using a bit of PTFE tape. Works very well, nice and reliable, Sirais are also good, just noisy and big.

Using a PID requires the Gicar PID unit, plus external transformer (12V), the onboard Hahn units used to fail, so they offboarded the transformers, then you got the temp sensor and some thin wires. PITA if they go wrong, much more expensive to repair/replace, no advantage. The exception is the transformer which can be had from Maplin for a few quid. I know because I have fixed early Duetto Gicar failures by removing the Hahn onboard transformer and using an offboarded maplin one with i think a 50 ohm resistor to fix them (the resistors required to drop the voltage a tad), otherwise you risk killing the Gicar unit, specifically the display..

They are Putting PIDs on HX machines, because they think you want them....this has mainly come about because of comments on USA forums. It makes the machines more expensive, but of course the price creep will be permanent, because they (manufacturers) have seen what you will pay. Trouble is, there is no going back now, belief has become fact and I would suspect that eventually all machines will come with PIDs.


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## Mrboots2u (May 10, 2013)

Brill ta. Are they worth the cash people add on to new machines to justify them. Again in the hxs?


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## Daren (Jan 16, 2012)

I was going to say exactly what Dave said


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## Daren (Jan 16, 2012)

What did Dave say in English.... Google translate didn't understand either. I need it in simple single syllable words with sentences limited to 5 words


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## DavecUK (Aug 6, 2013)

Daren said:


> What did Dave say in English.... Google translate didn't understand either. I need it in simple single syllable words with sentences limited to 5 words


PID not useful on HX. Or Lever Machines.


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## Daren (Jan 16, 2012)

Much better - now I understand


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## osrix (Feb 15, 2013)

Came on here to start a discussion on how Bezzera are measuring brew temp with their new Magica PID model. ( maybe they are just offseting the boiler temp ? )I have the original Magica and suddenly fancied sticking a PID in...I dont think i'll bother then.

I will read Daves 1st reply another 3 times though just in case


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