Power loss with 2.4KWt element?

[Codehopper]

So I've installed a nice and shiny 2.4 KWt heating element into my 50 liters kettle. At the moment it's connected using 1.5 mm2 cable of 0.6 m length, with a plug.

I had also bought a controller kit from Stil Dragon (http://www.stilldragon.com.au/diy-controller-kit/) thinking that I might need the full power only when ramping up the temperature, but for the boil itself I might need just part of the full power. The controller is now connected using 3 meters of 2.5 mm2 cable (socket on one side, plug on another).

So the system is plugged in as follows: kettle > controller > mains.

What I noticed is that I couldn't get higher than 98 degrees with 25-30 liters of wort and open lid, and the kettle is already insulated (2 plies of foam), and that's on a very warm evening. There is some roll of water in the kettle, but nothing compared to what I observed with gas. Closing the lid surely helps to establish vigorous boiling at 100C quickly, but the temperature goes back to 98 when I remove the lid.

So I have the following ideas for investigation:
1. Replace the cable on the kettle with 2.5 mm2
2. The controller may be stealing power, even when the dial is set to 100% power.
3. The 2.4 KWt heating element is simply insufficient for single batches.

I believe #3 is not the case, as I heard of working electric systems based on 2 KWt heating. Can anyone comment on #2? Anything I'm missing to check?

 

[klangers]

1. You can run some calcs on this to determine the voltage drop using good old Ohm's law (which is applicable in this case because the heater is a purely resistive load). Your house/dwelling cabling would be more relevant.
2. It would consume power, but this is irrelevant if 1) is not the problem
3. I run 2000 W on a 30L boil and that works ok. Very odd that it doesn't work for your 25L

My suggestions are:

1. Does the element have an inbuilt thermistor? My kettle stops heating if the element gets too hot. If it does, remove it and see what happens (don't disconnect, just move away from source of heat)
2. Buy a plug in power meter from Bunnings or similar. $30 and will tell you the power being drawn. If you're drawing 2.4 kW then the issue is your rig/too small of an element
3. Plug an incandescent lamp into the same circuit as your kettle rig is attached to. Turn on the kettle. If the lamp dims noticeably then your house circuits are causing a substantial voltage drop and may not be sufficient for the power you are trying to draw
4. Plug in the kettle without the controller and see what happens

 

[Codehopper]

Thanks klangers!

The heating element is this one: http://www.5stardistilling.net/weldless-2400w-element-guard/ -- I don't believe it has any smarts in it.

My (rented) house's wiring may be the cause, actually, as it's an old house. I'm using the same socket to which the washing machine and the dryer are normally plugged, but I doubt they together are more than 2KWt or so. I'll try the lamp test to confirm.

I guess if the house is the problem I will have to somehow subsist with it, and hope that my next dwelling will be better.

 

[Milk-lizard84]

Interesting that this topic came up. I am having the same problem with my 5 star element. I'm using it in my hlt and did a wet test to see if it leaked and noticed with only 30l of water I also only got to 97 degrees. Was kinda boiling but not very vigorously. Mine is just plugged straight into the socket. I think my mate wires it with 2mm cable.

 

[Codehopper]

Milk-lizard84, I wonder if it has any relation to the fact that they don't need really vigorous boiling in distilling? I'll drop them an email to see if there are any extra smarts in the element. Worst case we'll have to find some other element

 

[Maheel]

have you run it without the controller?

i would not have bothered with the controller for 2400w

it could just be a dud element and only pulling a low W or something they are made in OS (china?) etc so quality is sometimes a little questionable......

i get a nice rolling boil with a 2400 in a keggle, takes a little while to get into a good roll but it does
i heat up with the lid on and then remove lid once rolling boil

with my 3600W i run a controller if using it in the boiler, but full blast on the HLT

 

[kunfaced]

Do you have a multimeter? test the resistance across the element and apply ohms law. That will tell you a bit about the quality.

 

[Camo6]

Like kunfaced suggests, if you can measure the resistance of your element (completely isolated from circuit) you can calculate the power output.

ie, P = V2/R. If it was a 2400W element on a 230V supply (which may vary considerably) you could apply R=V2/P giving you a theoretical resistance of about 22 ohms. If you can confirm this I'd be confident of the elements condition.

It'd be worth getting someone to confirm your supply voltage if you're concerned about the houses wiring too.

 

[QldKev]

With all elements they have a given temperature coefficient of resistance. So the resistance will increase based on the temperature of the element. Hence at 20c it may calc out to be 2400w, but at 97c it is more likely drawing (approx) 10% under (depending on the actual coefficient).

 

[kunfaced]

Do you guys run these things on dedicated circuits? How about the 3600w element, did you have to install a 15A outlet or you chopped down the earth pin? Just curious havent read much into electric brewing.

OP did you happen to try boiling outside in the weathers? Or were you inside somewhere? Was it cold or windy etc?

 

[Maheel]

yes my 3600 is on a dedicated circuit and i use these 3 pin plugs for it and extra thick wire

 

[Codehopper]

Do you guys run these things on dedicated circuits? How about the 3600w element, did you have to install a 15A outlet or you chopped down the earth pin? Just curious havent read much into electric brewing.

OP did you happen to try boiling outside in the weathers? Or were you inside somewhere? Was it cold or windy etc?

As I said I don't run it on a dedicated circuit - just the same socket from the laundry room that usually has washer and dryer.

So far I did two boils, both outside, but hey it's summer. Also I have insulated my kettle to the point that it serves me well as a mash tun, too, and I don't remove insulation.

 

[dicko]

As I said I don't run it on a dedicated circuit - just the same socket from the laundry room that usually has washer and dryer.

So far I did two boils, both outside, but hey it's summer. Also I have insulated my kettle to the point that it serves me well as a mash tun, too, and I don't remove insulation.

It may depend on how your house is wired.

The outlet in the laundry may not be a dedicated circuit, it may be in series with other power points in the house and there may be other appliances drawing on that circuit.
Take the fuse out that protects that circuit and then go around your outlets with a normal bedside lamp or similar and see what other power points are on that circuit. The power points that the lamp doesn't work in with the fuse out are all on the same circuit.

 

[wynnum1]

How many solar power units feeding into your areas power supply and other heavy users could be stressed electricty system.

 

[lickapop]

Haha^^^

My 2c. You need 3600w element to get 50l to a nice boil in a respectable timeframe

 

[Maheel]

i reckon it's not pulling the full 2400w and you should have someone test it with a multimeter etc.

carefull it's 240V were talking about....

^^^^ my 3600 just pulled 45L to a boil from say 25c in about 40mins

 

[Codehopper]

^^ actually since I abandoned gas I'm not going to run 50 liters batches, but it's still good to have a big kettle to fit BIAB bag or a malt pipe (my next project). My issue is with single batches (25-30 l as I mentioned).

 

[Codehopper]

^^^^ my 3600 just pulled 45L to a boil from say 25c in about 40mins

Did you connect it to mains directly?

 

[lickapop]

I run those SD controllers and never had an issue.
1x controlled 3600w element and 1x3600w uncontrolled element on dedicated circuits for 120l
I also use a 2400w controlled element for a rims. Which is also on its on circuit as it would flick the safety switch if I ran a industrial fan (wattage unknown) at the same time on the same circuit
If I was going to take a guess at your problem I would check your temps with a different or calibrated thermometer if you haven't already done so.
Most elements work or they don't and those SD controllers would be the same but the only way to check is like the others have said and throw a multi over it and see what it's drawing at 100%

Imo 2400w element is for 25l tops

Have you tried the element without the controller?

 

[Maheel]

Did you connect it to mains directly?

it was running on a PSR25 controller (which is just a VR-SSR much like the SD ones) but at full on the dial the whole time.
i could have run it without the controller but just rewired it so was testing