ssr and variable ssr

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

Help Support Homebrew Talk:

gr3

Well-Known Member
Joined
Apr 8, 2015
Messages
69
Reaction score
0
I'm wanting to use a variable relay with pot. But also have ssr wired to variable relay. I'm going to have a switch that I can switch between relays. Can I do this wont the variable relay come on full when the other relay shorts across the pot side of variable relay?
 
OP
G

gr3

Well-Known Member
Joined
Apr 8, 2015
Messages
69
Reaction score
0
What kind solid state relay would work as a normal open or close switch since there will be no voltage just a open and close circuit.
 

Brumateur

Supporting Member
HBT Supporter
Joined
Jan 13, 2014
Messages
563
Reaction score
91
Any potentiometer controlled SSR . If SSR conracts for pot closed SSR is fully opened if contacts opened SSR is closed.
 
OP
G

gr3

Well-Known Member
Joined
Apr 8, 2015
Messages
69
Reaction score
0
I'm wanting to use a solid state relay to close terminals on the pot side of ssvr. But ssr don't close like a mechanical relay but they need voltage. Is there one that doesn't?
 

Bobby_M

Vendor and Brewer
HBT Sponsor
Joined
Aug 3, 2006
Messages
25,544
Reaction score
4,767
Location
Whitehouse Station
Can you explain the bigger picture for what you're trying to do? Are you trying to use a PID to control one SSR and then be able to switch over to SSVR control of the same element? My continued argument is that you don't need to switch between those two functions because they can be done in series and simultaneously. To null out the PID controlled SSR, just set the SV to a temperature over 212 and now the SSVR is purely setting power output. In reverse you can set the SSVR to 100% output and the PID will work like the SSVR isn't there. The 3rd situation you can't have with an either/or switch is such that the PID is functioning to reach or hold SV but you can dial in a max power output at the same time. Yes, the PID tune will be a little off but it's not a reason to avoid this.
 
OP
G

gr3

Well-Known Member
Joined
Apr 8, 2015
Messages
69
Reaction score
0
Yes that what I'm trying to do and understand what you are saying. I was just trying to get around having to adjust pid when I flip over to manual.
 

doug293cz

BIABer, Beer Math Nerd, ePanel Designer, Pilot
Staff member
Mod
Lifetime Supporter
Joined
May 14, 2014
Messages
11,927
Reaction score
8,304
Location
Renton
Something like this might do what you are trying to accomplish:

2000W-120V 1 element 1 pump dual control.jpg

This one is designed for 120V system, but conversion to 240V is straight forward.

Brew on :mug:
 

Bobby_M

Vendor and Brewer
HBT Sponsor
Joined
Aug 3, 2006
Messages
25,544
Reaction score
4,767
Location
Whitehouse Station
That's almost it but the DSPR1 is more like a PID with control pulse output. The OP was asking about a SSVR.

The only way I'm aware of switching between a PID controlled SSR and a SSVR as it applies to a single element is to use a high current double throw switch with the element on the common. GR3, you mention wanting to avoid messing with the PID when going manual. Here are the two scenarios...

1. As mentioned above, double throw switch can select between PID and SSVR. To go to manual you throw the switch and adjust the knob. With this solution the PID cannot regulate maximum power applied and it will cost you a switch. (on the other hand, you should have a positive disconnect anyway so you could use a DPDT switch with center off to kill two birds. Google Bryant 3025.).

2. Use the inline method I mentioned. To go to manual you set PID to 220F and adjust the knob. Again, the benefit is being able to use the knob at any time even when the PID is at a realistic set point. You don't mention if you're planning to use it for BIAB or mash control of any sort so the value of setting max power in PID mode can't really be determined. Because I use a recirculating eBIAB system, it's extremely valuable. Without the need for a double throw switch, you can achieve positive disconnect with a cheaper single throw switch.
 
OP
G

gr3

Well-Known Member
Joined
Apr 8, 2015
Messages
69
Reaction score
0
Why can't you wire ssr and ssvr to element and use dpdt switch to select between pid and pot?
 
OP
G

gr3

Well-Known Member
Joined
Apr 8, 2015
Messages
69
Reaction score
0
Scenario 1 you are doing on voltage side. I'm wanting to do it on pid and pot side with regular dpdt. Can this be done?
 
Top