Float switch suggestions

I've been wanting to add a float switch to my HLT since in the past I've accidentally dry fired my element. I've seen mention of people using one of these http://www.ebay.com/itm/Sus304-Stainless-Steel-Curve-Water-Level-Sensor-Liquid-Float-Switch-/271124589725?pt=LH_DefaultDomain_0&hash=item3f2048ec9d

Does anyone using one of these float switches have any trouble fitting it in the kettle with a HERMS coil installed? I'm not near my HLT right now but I wasn't sure if there was enough room to squeeze one in. It looks like a really close fit.

Also, I thought it'd be nice to have one that had 1/2" NPT threads so it could be installed into a full coupling from the inside of the kettle instead of weldless.

I've contacted Auber Ins. about this and they are interested in carrying a float switch for us electric brewers. They thought it would not be a problem and that they had enough market for it, they just need to know what options people would prefer.

So what do you all think about design, dimensions, wiring options-panel mount, qd ect? Is it even necessary to have something different than what's already available? Just spitballing here, thanks!

I have one in my HLT, its a tight fit, and the HX coil is a little Higher than Id like because of it. If any thing Id like it to be longer so the HX coil could fit around it.

Bsquared said:

I have one in my HLT, its a tight fit, and the HX coil is a little Higher than Id like because of it. If any thing Id like it to be longer so the HX coil could fit around it.

Click to expand...

Thanks.

How much clearance is there between the float and the kettle wall? I'm thinking if it didn't stick out quite as much it would be easier to install near the wall and not have to have it come up through the HERMS coil.

I'm not home but I think it is about 3/4-1.5" off the wall. the float is about 1"in diameter so there is room to get it closer to the wall. If there are some engineers looking to make some thing too, a sight gage/level sensor would be awesome! but Ill settel for a better float switch.

Awesome! Thanks for the pics and the info.

I've ordered one of those float switches from China to play around with along with some Switchcraft dc connectors and a switch.

I'm looking forward to being able to work on this for my own set up.

So I got around to installing a float switch in my HLT and everything is working.

I had previously soldered a 1/2" half coupler for an anode, so I used that coupling and a 1/2"x1/4" NPT SS bushing from a sightglass I accidentally broke from brewhardware.com. I drilled the remaining sight glass/polycarb that was left in the bushing hole out to 3/16" if I remember correctly (I may not-I eyeballed it). I then carefully dremeled down the inside nut on the float switch until it was round and fit into the 1/2" bushing. I put the silicone gasket on and installed the float from the inside. It came out just right. It's very close to the kettle wall but with plenty of room to float freely.





This is the 1st float switch I did this with. I accidentally broke the wires off so I replaced it with the same float.





I silver soldered the outside SS nut to a piece of 1/2" tubing so I couldn't knock the connection off anymore.

I used these dc switchcraft connections. I also used this switch to switch the negative wire going to the SSR from the PID. The way it works is that when I switch up, the hlt float switch makes or breaks the negative dc feed to the ssr. When switched to the middle or down, the pid neg is directly connected to the SSR for using the BK which doesn't have a float switch. Caveat: you have to make sure that you have the switch up when using the HLT if you want to have the float switch protection!

I'm not an electrician or EE so take this for what it's worth. This worked for me but there are other, possibly better ways to do it. There is an old thread around here somewhere where passedpawn drew something like this up for somebody. It was very helpful.

This is my bad drawing. The negative from the PID is branched off into two wires (twisted,soldered, heat shrinked). One wire goes to the float switch and one goes to the toggle switch pin 3. The other wire of the float switch goes to pin 1. The middle pin (2) is connected to the SSR. Pins 4,5, and 6 are not used in this application. (see linked switch, NKK M2024 documentation. Note: I did not do any external connecting of pins as noted in that doc.)



The switch pics are all upside down as it's installed on the open lid of my
controller.







Hopefully this makes sense and is helpful. I'm not very savvy with this stuff so I used my ohm meter to check everything to make sure I understood how it all worked. It worked exactly like I hoped this past weekend.

Oh yeah, Auber (no affiliation) just started carrying this float switch here.

I reckon this is a good safety feature. Costs less than a blown element. Yes I've done it too

Don't like the M10 thread on the float switch though.

Has anyone bought one of these who is willing to measure the OD of the tube? I don't like how it mounts, either. I'm thinking we can cut off the hex and threaded part and use a compression fitting if the tube is compatible.