22 replies to this topic

[MoreAmmoPlz]

I'm currently in the process of upgrading my boil kettle to 240v in order to get a better rolling boil and plan on installing a 4500 watt element in addition to the 1650 watt element already in there. What I'd like to do is run both elements up until I get some boil action going and then just flip off the 1650 watt element. These will be 10 gallon batches and I've seen 3600 watts thrown around as the amount of power necessary for a volume of that size so I'm about 900 watts over. Is this going to boil too hard and boil off too much water and darken the wort?If it comes down to it I'll go the PID/SSR route but I really like to keep things simple.

[djinkc]

If you're using a converted keg you will probably want to be able to control the boil. I have a larger diameter Al kettle, I seldom need to cut power on it. 10+ gal batches here too.

[stangbat]

What kind of kettle do you have? I have 4500 watts in a keg and full power is a very vigorous boil. I usually back it down a little bit. But as DJ said, with his large diameter kettle, 4500 watts at full power is just right. So I guess the answer is, it depends.

[BrewerGeorge]

What kind of kettle do you have? I have 4500 watts in a keg and full power is a very vigorous boil. I usually back it down a little bit. But as DJ said, with his large diameter kettle, 4500 watts at full power is just right. So I guess the answer is, it depends.

Yep, with a keggle 4500W is a bit too vigorous - somewhere around 2gal/hr. It goes against intuition, but total volume doesn't have much affect on boiloff rate, at least not as much as surface area. OTOH, I brewed in the keggle with 4500W unregulated for almost a year. You just have to increase the amount that goes into the kettle in the first place. It does get slightly darker, but I never noticed a flavor change.

[MoreAmmoPlz]

Yeah I'm brewing in a converted keg so it is starting to look like a PID/SSR is in the stars for me.

[MoreAmmoPlz]

What do you guys think of this wiring diagram? I apologize in advance of the crudeness but I just whipped it up. And to ease everyone's mind, since it is 240v, everything will be looked over by an electrician before it gets fired up. [attachment=84:WiringPlan.jpg.png]

[HVB]

What do you guys think of this wiring diagram? I apologize in advance of the crudeness but I just whipped it up. And to ease everyone's mind, since it is 240v, everything will be looked over by an electrician before it gets fired up. [attachment=84:WiringPlan.jpg.png]

I would add a Double pole switch between the SSR and the Element. That way if there is an emergency you can flip the switch and kill the power to the element.

[davelew]

I would add a Double pole switch between the SSR and the Element. That way if there is an emergency you can flip the switch and kill the power to the element.

Always put in an off switch. The one time I didn't do this I accidentally melted some titanium.

[MoreAmmoPlz]

You guys don't think the DPST off the supply line is enough?

[HVB]

You guys don't think the DPST off the supply line is enough?

If you shut that switch off it will shut off the PID also. If you have one between the PID and the element you can just shut the element off. I am not sure what PID you have but you may have to re-enter set points and what not if you kill the main source. Also, I like to shut my elelement off but still have the PID on when I chill, that way I know what the wort temperature is.for the cost of a switch I think it is well worth it.Mike

[djinkc]

You guys don't think the DPST off the supply line is enough?

Mine's before the SSR, just in a handy place.

[stangbat]

Another reason to have an off switch when using a PID in manual mode to control the boil is that it lets you cut power quickly when you have a boilover. Most PIDs have a lag between when you select the power and it applies the setting. It can be several seconds. When you have a boilover, you want the power cut immediately so that it stops. Pressing the button on the PID to lower the power, holding it so that it goes down several %, then waiting for it to apply the lower power all while your wort and hops are spilling over the side of the kettle is no fun.

[HVB]

Another reason to have an off switch when using a PID in manual mode to control the boil is that it lets you cut power quickly when you have a boilover. Most PIDs have a lag between when you select the power and it applies the setting. It can be several seconds. When you have a boilover, you want the power cut immediately so that it stops. Pressing the button on the PID to lower the power, holding it so that it goes down several %, then waiting for it to apply the lower power all while your wort and hops are spilling over the side of the kettle is no fun.

Another good point. When I do 10 G batches I have to man the switch for the first few mintues to make sure there is not boilover.

[stangbat]

Another good point. When I do 10 G batches I have to man the switch for the first few mintues to make sure there is not boilover.

You could also have a switch to just turn off the PID in the case of a boilover, but I feel that being able to kill the power to the element is a safer option in general.

[HVB]

You could also have a switch to just turn off the PID in the case of a boilover, but I feel that being able to kill the power to the element is a safer option in general.

I agree 100%

[MoreAmmoPlz]

Alright, two switches it is. Apparently this isn't going to get done all that cheaply.

[3rd party JKor]

Yep, with a keggle 4500W is a bit too vigorous - somewhere around 2gal/hr. It goes against intuition, but total volume doesn't have much affect on boiloff rate, at least not as much as surface area.

Yeah, less volume (for a given kettle geometry) will actually have a higher boiloff rate, because there is less area on the sides/bottom of the kettle for heat to transfer away from the liquid.

[BrewerGeorge]

Alright, two switches it is. Apparently this isn't going to get done all that cheaply.

I hust used regular-looking DPDT light switches from Lowes. About $5 each.

[djinkc]

You could also have a switch to just turn off the PID in the case of a boilover, but I feel that being able to kill the power to the element is a safer option in general.

Don't SSRs frequently fail with the circuit completed?

[stangbat]

Don't SSRs frequently fail with the circuit completed?

I believe that they are more likely to fail closed than a mechanical relay, but I'm certainly no expert. So this is probably another argument for switching the load rather than the PID or the input to the SSR.