Electrical suggestion please

[RabMaxwell]

Hello all i want to use a spare temperature controller to heat a kettle element in my mash tun. so i can set it before i go to bed then i can mash first thing in the morning. But my temperature controller can't handle the load needed for a kettle element. So can someone tell me what type of switch or relay i would need.Cheers

[Frothy]

What kind of temperature controller is it? Would it be able to control a solid state relay SSR? These are what are used with PID's & are cheap to pick up 2nd hand on Ebay.

Frothy

[Andy]

Can't you just use a timer switch that switched "on" at a given time ? Obviously that relies on you getting up in time to turn it off such that it doesn't get too hot Or you could calculate the amount of time required to heat the volume of water and get the timer to turn the element off after the required time just-in-case.

[RabMaxwell]

Hello it's one of my LAE MTR temperature controllers i used to use for fermentation until i got new ones recently off ebay.The plan is to set my mash tun to strike temperature. so that i can save an hour heating it in the morning. Probably a SSR would do i was told at my work to get a contactor . But when having a google they seem quite pricey if i pick something up i will post back and see if Frothy can do me one of his drawings for the wiring. Cheers

[Frothy]

The tech' sheet for your controller is here -> http://www.hawco-refrigeration.co.uk/pdf/p39.pdf
I'm afraid I can't tell wether it would use an SSR or not.

I'm no expert but I did do this rough sketch of wiring my PID to the SSR.
http://www.pbase.com/mattw/image/68995966

Frothy

[RabMaxwell]

Cheers Frothy should do the trick

[Andy]

Rab, you can't connect your temp controller directly to a SSR because your controller doesn't output a voltage (which the SSR needs to do its switching).

You could use a low voltage DC power supply and connect its output to the SSR switching terminals via the relay-out terminals of your controller. If you can set your controller to turn offf its output relay when a specific temp is reached (your strike temp) then the SSR will switch off when the relay turns off. You'd connect the mains power to your heater element through the SSR "out" terminals.

[RabMaxwell]

Hello Andy I think it doe's output a voltage hear is what it's got on the back
Mod. MTR122T1RE
Input -50 -150c PTC
Out1 8 (3)A 240 Vac Cool
PWR 230V~+10%2w
When i used it out (2) went to power a light bulb & out (3) went to power a fringe (4) power from mains (1) &(4) Joined Live loop (5) neutral (11) &(12) PTC probe.
Probably take to my work and ask one of the electricians to draw a little diagram. And ask if a ssr is suitable i can also bribe him with cakes for a free ssr & save buying one.Cheers

[SteveD]

Can't you just use a timer switch that switched "on" at a given time ? Obviously that relies on you getting up in time to turn it off such that it doesn't get too hot Or you could calculate the amount of time required to heat the volume of water and get the timer to turn the element off after the required time just-in-case.

I vote for the 'timer switch', about £4.00 in Ikea, working in conjunction with an 'alarm clock' available at Robert Dyas, clock shops, on mobile phones, etc.

The timer wakes your boiler up, the alarm clock wakes you up X minutes later.

The calculation you need to do is:-

X = Z-Y where

Z is the time your boiler takes to get to temperature from a standing start. Y is the time it takes you to become concious, fall out of bed, get washed, dressed, downstairs, etc.