PID question

[rod734]

I'v been browsing the PIDs on ebay, does all of them have the manual mode so you can controll the amount of power to the element? If not how do you determine if it's the right one for a brew kettle.

thanks

 

[P-J]

This is the one you want (need). It is an excellent unit that is very commonly used by many on this forum.

PID TEMPERATURE CONTROL CONTROLLER, SSR, W/ DUAL ALARM

It has the manual mode and is very easy to control and use.

A lot of PIDs on the market do not have manual mode. This one does.

 

[rod734]

I seen this on a pid and it was pretty cheap,

Control method: PIN control (including ON/OFF, step-type PID and continuous PID) and self tuning control
Proportional band (P): 0~full range (ON/OFF control when set to 0)

does this mean you can controll the percent of power to the element?

 

[Bullbythehorns]

No, it doesn't control the percent of power going to the element. It turns the element on for the for percent of time you have it set at over the course of 5 seconds (just guessing on the 5, someone may know exactly what timeframe it is.) I set mine at 80% after a I get rolling boil and it will get the kettle to rocking as you see the boil "turn on-turn off".

 

[rod734]

No, it doesn't control the percent of power going to the element. It turns the element on for the for percent of time you have it set at over the course of 5 seconds (just guessing on the 5, someone may know exactly what timeframe it is.) I set mine at 80% after a I get rolling boil and it will get the kettle to rocking as you see the boil "turn on-turn off".

Yea, thanks for the reply. I just worded it wrong, I had read how they work on another post. I will post the complete specs., and maybe someone can tell if it is like the manual mode that is redomended. I'v worked with electricity quite a bit, both AC and DC for the railroad and coalmines, as well as residential, but I dont understand all the terminology used in the specs. The proportional band makes my think this may work.

Temperature control range: 0 ~ 400°C
Input: K thermocouple
Output: relay
Accuracy: ±0.5%RS
Cold-end compensation tolerance: ±2°C (can be modified via software in 0 ~ 50°C)
Resolution: 14 bit
Sampling cycle: 0.5 seconds
Alarm function output: 1 way, 12 modes
Contact capacity of output: DC4——20MA (resistive load)
Display: process value (PV), setting value (SV): 1999 ~ +9999
Setting value (SV): identical to measuring range (PV)
Control method: PIN control (including ON/OFF, step-type PID and continuous PID) and self tuning control
Power supply voltage: AC 85 ~ 240V, 50/60Hz
Relay contact output rated: AC220V, 3A
Proportional band (P): 0~full range (ON/OFF control when set to 0)
Integral time (I): 0 ~ 3600 sec (No integral action when set to 0)
Derivative time (D): 0 ~ 3600 sec (No derivative action when set to 0)
Proportional cycle: 1 ~ 100 sec
Hysteresis loop of step-type controlling output: 1 ~ 100℃ (or other PV unit)
Insulation resistance: >50M ohm (500V DC)
Insulation resistance: 1500V AC/min
Power Consumption: 10 VA
Operating environment: 0 ~ 50℃, environment with no corrosive gas 30 ~ 85% RH
Dimensions: 48 x 48 x 107mm
Cut out dimensions: 45 x 45 x 99mm
Weight: 140g

 

[P-J]

Temperature control range: 0 ~ 400°C
Output: relay
Relay contact output rated: AC220V, 3A

That right there tells nearly the whole story.
The PID is designed for control using °C.
It uses relay output and would not be for use with a SSR.
I believe this PID will not support manual mode and it will also be difficult for you to manage an accurate set temperature for heating HLT water. Relay output on a PID is something you do not want unless you are controlling a refrigerator, freezer or some other motor driven device.

IMHO.

 

[rod734]

Temperature control range: 0 ~ 400°C
Output: relay
Relay contact output rated: AC220V, 3A

That right there tells nearly the whole story.
The PID is designed for control using °C.
It uses relay output and would not be for use with a SSR.
I believe this PID will not support manual mode and it will also be difficult for you to manage an accurate set temperature for heating HLT water. Relay output on a PID is something you do not want unless you are controlling a refrigerator, freezer or some other motor driven device.

IMHO.

Thanks for the info., with just a 3A contact rating they wouldn't be very useful. They are only $19 shipped. Could you use a cheap 220v cell phone charger off the output relay to trigger an SSR or even a 110 off one leg of the output relay. I'v already ordered one of the Auberin pid, but I just like tinkering and expermenting. I intend to include some electronics classes in my Bio-tech program, but that will be later.

 

[P-J]

It might be cheap - BUT - you need to weigh out what you are going to use it for and how. $20 is very cheap for a PID but when it sits on a shelf unused it is not so cheap anymore. Yes you can use the relay contacts to energize a SSR however, you still need to cycle it reasonably slow or you will damage it very quickly. (relay chatter).

Think about it or just get it for experiencmentation. Good luck.