modulating 4500w heatstick

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
F

F_R_O_G

Well-Known Member
Joined
Nov 29, 2013
Messages
212
Reaction score
14
Location
north Seattle
would have thought i would find this answer in a search, but i couldn't find it.

I have a 4500w 240v heatstick that i'm trying to modulate. just need a dial, don't need to get all fancy. would i use something like what this guy suggested work?
freddyb said:
Buy this: http://www.bakatronics.com/shop/item.aspx?itemid=383

Replace C1 with a 2.2uF capacitor to lower the frequency.
Use a 12V wall wart as a power supply to the PWM board.
Connect the output of the PWM board to a SSR to control your boil.

This is how I did it and I'm very happy. Cheap, easy, responsive control.
Click to expand...

and hook it up to this SSR http://www.amazon.com/dp/B005KPIX9A/?tag=skimlinks_replacement-20

would i need anything else? i hear people putting heat sinks on the SSR, but i don't know if i really need it if i am switching slower than 1Hz. am i right? do i need anything else besides wires and a box? thanks for the help

btw, made my heatstick out of just copper, so no zinc/(not sure if this sealant is really safe) poisoning
 
Last edited by a moderator:
Yes, that will work. And yes you would need a heat sink for the SSR like this one:

http://www.amazon.com/gp/product/B005D6145G/?tag=skimlinks_replacement-20

That setup will give you manual linear control of your temp output.

The other suggestion I've seen on here is a SSVR (solid state voltage regulator). Then you only need the SSVR and a potentiometer. There is no circuit board soldering involved with that option. But it isn't true linear control, so it might take a little getting use to.
 
Last edited by a moderator:
A SSVR is probably the best solution and you will need a heat sink. SSRs dissipate about 1 watt for every amp you push through them and without a heat sink your SSR will fail.
 
so a SSVR would bring down the voltage to the heating element right? so bringing it down to 120v with a SSVR for example would give me 1125w?

would this work
http://www.amazon.com/dp/B008MPLIJM/?tag=skimlinks_replacement-20

what would you use to regulate the SSVR?

sorry for all the questions, new to the practical side of electronics.
 
Last edited by a moderator:
No, SSVRs do not control voltage, it controls effective power output by modifying the phase angle. To control the SSVR you linked to, you need the potentiometer that shows in the related items list.
 
Warning, pedantic explanation ahead...

An SSVR has an impact on the net power flow to the load, but its direct action is to control the flow of current from source to the load (either block or allow, more or less).

An SSVR is a triac circuit, like a dimmer, based on two antiparallel thyristors.

The potentiometer controls the phase angle at which the switch will 'close' and allow current to conduct. Once the current reaches zero, which will always happen in an AC system, the switch automatically opens again until it receives the control signal that says close again. The potentiometer, in conjuction with a built in IC, provides that control signal. How long the circuit waits into the voltage AC cycle to send the 'close' command depends on the resistance of the potentiometer

http://en.wikipedia.org/wiki/File:Triac_funktion.gif

The switch only regulates when your load is or isn't connected to the power source.

Stilldragon has a cheap kit people seem happy with. Cheap, easy, gets the job done.

http://www.stilldragon.com/diy-controller.html


I'd add a suitably rated switch, as the SSVR will likely allow some small amount of power flow even with the potentiometer railed. Doesn't need to be a fancy relay, this will work fine:

http://www.homedepot.com/p/Leviton-...le-Pole-Switch-White-R62-03032-2WS/100356941#

The stilldragon kit and that switch, IMHO, is the easiest way to safely control the heating element. Naturally, you need a GFCI protected circuit as well.
 
Well its just a good question.. I plan to build one of these soon and want to keep informed.

I was also going to email http://www.stilldragon.com/diy-controller.html for more info on the specifications to this build like, what are the parameters for the potentiometer and I am assuming that its a 40 amp ssr. I did not see this info listed on the link given.

What about some kind of breaker?
 
If you buy the kit it includes the SSVR and the pot. The SSVR will have a spec for the resistance range and watt rating of the potentiometer.
 
You want both over current protection and ground fault protection. A 30a gfci breaker will do both.

I got a spa panel that has a 50a gfci. The wiring I used is 10g so I added a DIN mounted 30a breaker as well.
 
Don't know if this is reviving an old thread or beating a dead horse...

I have an electric setup which I would like to add variable output control to one element.

Here's my current system.

60amp breaker in panel goes to 60amp spa panel.
Spa panel connects to control box with 4 on/off switches controlling 4 SSRs (interlocked so that only two switches will activate at a time)
SSRs connect to 5500 watt elements - 2 in HLT, 2 in boil kettle

The issue I have is that 2 elements in my boil kettle are needed to get to boil. Once at boil, 2 is too many, 1 is just enough. I'd like to add a portion of the second element to get a better boil without over doing it.

Can I use the stilldragon kit in the post below and add it inline between the main control panel and the element. If the main panel is off, then there will be no power, but when it is on I can then control the output. I'd like to keep the main panel with the interlocked switches as it is if possible.



BadWolfBrewing said:
Warning, pedantic explanation ahead...

An SSVR has an impact on the net power flow to the load, but its direct action is to control the flow of current from source to the load (either block or allow, more or less).

An SSVR is a triac circuit, like a dimmer, based on two antiparallel thyristors.

The potentiometer controls the phase angle at which the switch will 'close' and allow current to conduct. Once the current reaches zero, which will always happen in an AC system, the switch automatically opens again until it receives the control signal that says close again. The potentiometer, in conjuction with a built in IC, provides that control signal. How long the circuit waits into the voltage AC cycle to send the 'close' command depends on the resistance of the potentiometer

http://en.wikipedia.org/wiki/File:Triac_funktion.gif

The switch only regulates when your load is or isn't connected to the power source.

Stilldragon has a cheap kit people seem happy with. Cheap, easy, gets the job done.

http://www.stilldragon.com/diy-controller.html


I'd add a suitably rated switch, as the SSVR will likely allow some small amount of power flow even with the potentiometer railed. Doesn't need to be a fancy relay, this will work fine:

http://www.homedepot.com/p/Leviton-...le-Pole-Switch-White-R62-03032-2WS/100356941#

The stilldragon kit and that switch, IMHO, is the easiest way to safely control the heating element. Naturally, you need a GFCI protected circuit as well.
Click to expand...
 
Thanks. I assumed it would work but this is the first electrical modification I will be making by myself. Had an electrician build the basic controller panel to my spec. I'm confident I will be able to sort out the connections for the secondary variable switch.
 

Similar threads

T
Homebrew interface built in Qt for Raspberry Pi
Replies
9
Views
3K
nordork
N
Clint Yeastwood
Speidel Sent me a Braumeister Cable
Replies
11
Views
2K
Clint Yeastwood
Clint Yeastwood
D
remote pressure monitoring
Replies
19
Views
2K
DuncB
D
T
HERMS Controller Crossroads
Replies
2
Views
701
Timothy Schwitz
T
K
SSR vs Mech Relay/Contactor for boil?
Replies
15
Views
2K
kenc_zymurgy
K

Latest posts

Back
Top