Simmerstat, Are They Good To Use Or Not?

[ShredMaster]

I've managed to acquire one of these which is rigged up in a little control box with the leads.

I opened it up to see what it actually was and the knob is controlling a simmerstat. I just bought a 2200W element and am in the process of rigging it up to give me a boiler and was wondering whether to use this.

From the searches I did, there are really mixed opinions on whether they are good to use or not, as in, whether they are "bad" to use. It seems like a pretty neat idea having a knob to control my element, apparently simmerstats is how the common kitchen stove is controlled.

Are there any issues using one? Is it actually as cool as it seems to use one?

 

[QldKev]

I've managed to acquire one of these which is rigged up in a little control box with the leads.

I opened it up to see what it actually was and the knob is controlling a simmerstat. I just bought a 2200W element and am in the process of rigging it up to give me a boiler and was wondering whether to use this.

From the searches I did, there are really mixed opinions on whether they are good to use or not, as in, whether they are "bad" to use. It seems like a pretty neat idea having a knob to control my element, apparently simmerstats is how the common kitchen stove is controlled.

Are there any issues using one? Is it actually as cool as it seems to use one?

since you can get a stc-1000 for $16 upward I hope you did not pay too much for your guess is best thermostat

 

[ShredMaster]

nah it's definately not a thermostat, it only regulates power.

I didn't pay a cent for it tbh, it came as part of some "old brewing gear" this bloke used to have to kick me off into an AG setup. It's a simmerstat controller but I'm wondering why (from searching on here) some people seemed to say they were bad to use. The threads got a bit too technical and went on explaining how they worked from a technical point of view, I still can't work out whether it is safe to use or there is real reasons not to use it.

I could always plug it in and see but I'd rather not just yet, unless it will actually do the job I think it will do.

 

[joethebrewer]

Hi, dragging up an old thread here.

Im looking at setting up a control box for an electric setup.

its going to consist of two electric urns, one 20L and one 38L, both with 2Kw elements intstalled.

I'm looking at using one stc1000 in series with a mp101 style Simmerstat for the HLT
and one more Simmerstat for the BK.

the reasoning is that while the stc-1000 will cut the power to the element at the set point, it will not ramp down power at it gets close. this can be done manually with the simmerstat. Large ovens in bakeries often use this kind of control for bread baking.

Has anyone tried this before.
also to the original poster, how did you go with your simmerstat?

 

[booargy]

Simmerstat works on duty cycle so if your cycle is 10 sec @50% it will be on for 5sec and off for 5sec which is no good for controlling a boiler. What you need is to be able to reduce the power not cut it.

 

[joethebrewer]

Yes I understand that a Simmerstat works on a duty cycle. I think what you are saying is that the overall on/off cycle time of a Simmerstat (which might be as much as a minute) is too long a period to be useful in a boil kettle.

Does anyone familiar with pwm know if it would work in series with a stc-1000 instead of a PID?

 

[wessmith]

Yes I understand that a Simmerstat works on a duty cycle. I think what you are saying is that the overall on/off cycle time of a Simmerstat (which might be as much as a minute) is too long a period to be useful in a boil kettle.

Does anyone familiar with pwm know if it would work in series with a stc-1000 instead of a PID?

PWM on a 10 amp element? C'mon guys, lets get real! Any solid state temp controller, PID, SSR or simmerstat works by turning the current ON or OFF. Exactly the same as the conventional elements on your stove. There is nothing wrong with a simple simmerstat - you just need to match the rated current with your element - they work on a bi-metalic strip that heats up and breaks the circuit, cools and remakes the circuit. Same as a mechanical thermostat actually except there is no temp calibration, just a time thing. "Proportional control" ie PWM, is the stuff of low power electronics.

Wes

 

[Maheel]

http://www.ebay.com.au/itm/140730716566?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

if your trying to control the "intensity" of your boil get one of these ^^^ and build i into a box with a fan etc
or one of those SSR variable resitance one's with a pot like this

http://www.ebay.com.au/itm/SSR-40VA-AC-24-380V-40A-Solid-State-Relay-Voltage-Resistance-Regulator-SSR-/160929961940?pt=AU_B_I_Electrical_Test_Equipment&hash=item25782c57d4


if you trying to control the temp of the liquid pre boil just get a STC-1000

 

[diydave]

When they are installed on a stove, you have the combination of the density of the element and the thickness of the pot base that holds heat and thus evens out the on's and off's of the cycle.

If you have an element inserted into a pot of water, or wort, do dont have as much density so the ons and offs of the cycle become more pronounced. This will give you to much variation to be used to boil wort and hold it at a good boil.

 

[wessmith]

When they are installed on a stove, you have the combination of the density of the element and the thickness of the pot base that holds heat and thus evens out the on's and off's of the cycle.

If you have an element inserted into a pot of water, or wort, do dont have as much density so the ons and offs of the cycle become more pronounced. This will give you to much variation to be used to boil wort and hold it at a good boil.

Sorry Dave, thats only part of the story. Water has density too. The only way to control a boil is by on/off, not by temp. Forget those fancy speed/temp whatever controls that Maheel suggested. If you work out the heat that needs to be dissapated you will see it does not compute. Water at 100C does not boil until you pump another heap of kJ into it for no temp change. So monitoring the boil essentailly becomes more a visual event - just like using a gas fired kettle. In the end the mass of the wort will even out the ons and offs.

Wes

 

[Maheel]

The only way to control a boil is by on/off, not by temp. Forget those fancy speed/temp whatever controls that Maheel suggested. If you work out the heat that needs to be dissapated you will see it does not compute. Water at 100C does not boil until you pump another heap of kJ into it for no temp change. So monitoring the boil essentailly becomes more a visual event - just like using a gas fired kettle. In the end the mass of the wort will even out the ons and offs.

Wes

nah mate your wrong what i linked to works the best

the thing i linked to works great i have several of them the 1st being triac based does switch on and off but just does it very fast

or another i have is a phase angle controller, and does somethign to the power phase

both allow me to adjust the "power" or "amps" to the element and therfore controll the "input" power to whatever is boiling

just like a gas flame being turned up and down

like i said if you want something to control intensity just get what i linked to... an easy fix

 

[wessmith]

nah mate your wrong what i linked to works the best

the thing i linked to works great i have several of them the 1st being triac based does switch on and off but just does it very fast

or another i have is a phase angle controller, and does somethign to the power phase

both allow me to adjust the "power" or "amps" to the element and therfore controll the "input" power to whatever is boiling

just like a gas flame being turned up and down

like i said if you want something to control intensity just get what i linked to... an easy fix

Well we agree then that it is just an on/off switch phase angle or not. Lets KIS

Wes

 

[booargy]

No it is not.
when a switch is on current flows, when a switch is off no current flows. the voltage regulator restricts the amount of current that flows.
The simplest way to control the boil is with gas by restricting the amount of gas going to the burner. if you use electricity you restrict the amount of current going to the element.

 

[wessmith]

No it is not.
when a switch is on current flows, when a switch is off no current flows. the voltage regulator restricts the amount of current that flows.
The simplest way to control the boil is with gas by restricting the amount of gas going to the burner. if you use electricity you restrict the amount of current going to the element.

Hi Booargy, would you mind explaining exactly how the VR works? We are talking about 10 amp elements I think.

Wes

 

[booargy]

voltage is inversely proportional to current. meaning as the voltage increases current decreases in proportion to voltage for a give wattage.

roughly if you have a 230v element that draws 10amp it will use 2300W.
P=VI so 230vx10A=2300W.

If you were to drop the voltage to 110v to get the same wattage we would have
I=P/V so 2300W/110V=20.9amps

So to calculate the wattage on our voltage controlled element we need a constant which is resistance. this can be calculated with
R-Resistance W-watts I-amps
R=W/(I x I)

so we end up with
2300W/(10Ax10A)=23 ohms

Now we can calculate the power consumption of an element for a given voltage with P=(V x V)/R

if we reduce the voltage to 200V (200V x 200V)/23ohms=1740W

if we reduce the voltage to 150V (150V x 150V)/23ohms=978W

if we reduce the voltage to 50V (50V x 50V)/23ohms=109W

AC electricity travels in a wave form so the voltage rises from zero to peak. the solid state voltage regulators crop the top off the wave at the set voltage. So what is in effect happening is the heat density of the element is being reduced.

Auberins ramp /soak PID units have a built in simerstat the menu heading is "OutH" the number is the percentage of the duty cycle on.

 

[wessmith]

voltage is inversely proportional to current. meaning as the voltage increases current decreases in proportion to voltage for a give wattage.

roughly if you have a 230v element that draws 10amp it will use 2300W.
P=VI so 230vx10A=2300W.

If you were to drop the voltage to 110v to get the same wattage we would have
I=P/V so 2300W/110V=20.9amps

So to calculate the wattage on our voltage controlled element we need a constant which is resistance. this can be calculated with
R-Resistance W-watts I-amps
R=W/(I x I)

so we end up with
2300W/(10Ax10A)=23 ohms

Now we can calculate the power consumption of an element for a given voltage with P=(V x V)/R

if we reduce the voltage to 200V (200V x 200V)/23ohms=1740W

if we reduce the voltage to 150V (150V x 150V)/23ohms=978W

if we reduce the voltage to 50V (50V x 50V)/23ohms=109W

AC electricity travels in a wave form so the voltage rises from zero to peak. the solid state voltage regulators crop the top off the wave at the set voltage. So what is in effect happening is the heat density of the element is being reduced.

Auberins ramp /soak PID units have a built in simerstat the menu heading is "OutH" the number is the percentage of the duty cycle on.

Ohms Law update aside, your explanation of the VR tallies with my understanding - the electronics are simply switching ON or OFF. That may be full output or it can be by chopping the sinewave to give an effect of reduced voltage.

In any event, the one thing missing in your explanation is heat. Electronic switching devices generate a lot of heat and that is the reason you dont find them on higher power devices. The Variable voltage device shown on Ebay in an earlier post does not show the continuous rated load - only a peak load (3800w from memory) I would suggest it will run VERY hot if you try to run a 2400w element at less than say 75% power.

Anyway, a couple of suggestions for controlling kettle elements:
1. Use paralell/series switching with 2 elements - say 2 x 1000w with either a manual rotary switch or a DPDT contactor. That will achieve either 100% or 50% without any electronics
2. For heavier use, use 3 x 1000w elements and switch each one individually to achieve 33%, 66% or 100%

The latter is what we do with the 20 and 40kW elements in our 500 and 1000 litre electric kettles. Works a treat.

Wes

 

[wessmith]

Anyway, a couple of suggestions for controlling kettle elements:
1. Use paralell/series switching with 2 elements - say 2 x 1000w with either a manual rotary switch or a DPDT contactor. That will achieve either 100% or 50% without any electronics
2. For heavier use, use 3 x 1000w elements and switch each one individually to achieve 33%, 66% or 100%

The latter is what we do with the 20 and 40kW elements in our 500 and 1000 litre electric kettles. Works a treat.

Wes

Sorry folks, now I have had my second cup of coffee I realise that suggestion "1" above is wrong. There are 3 modes available, 500w (series connection), 1000w (single element) and 2000w (both elements in paralell)

Wes

 

[treefiddy]

I gave the cheapo voltage regulator a go to turn down one of my 2400 W elements. It was so hot at 100% that I did not want to try reducing the voltage. If you must use one I would suggest using a larger heatsink with active cooling.

Power for my second element will now be through my PID/SSR.