E-HLT Build - Confirmation

[MFigz]

Hey all, I've been reading E-HLT threads for a few weeks now and I am very close to starting the build on my PID control box. So far I have a 3 prong dryer outlet not GFCI protected in my basement. I have installed the 5500w 240v Heater element into my HLT. I'm far from an electrician and my setup isn't exactly like anyone else's that I've read so far so I'm a bit nervous about this build and want to make sure I do everything safely and correctly. I am hoping you guys can offer some advice or tell me if I'm screwing anything up before I burn down my house.

1. First things first, I'm going to Home Depot tomorrow to get a 30a GFCI breaker to replace my existing breaker.
2. Coming into my control box will be a 3 wire 240v dryer cord, 1 of the 120v hot wires from the cord will go to my PID, which will then go to the SSR and then into one pole of a DPST switch and terminate into a 3 prong dryer outlet inside my control box. The other hot wire will go directly to the other pole of the DPST switch then terminate in the same dryer outlet in the control box. I think this should give me the ability to turn off my heater element while still monitoring the temp as the wort is chilling. I have read about the "ramping issue" with the element switched off, but I think it's a good idea to have a way to kill the heater if I want to. I suppose I could also just set my PID to 50 degrees when chilling, thoughts?
3. The ground/neutral wire from the cord will go to a grounding bar which will ground my PID, SSR and outlets inside the control panel.
4. I will also tap into one of the 120v hot wires and power a couple 120v switches/outlets to control the Herms pump.
5. I'm considering installing the SSR with the Heat sink inside the control box with vent holes drilled in the side (possibly may get a small PC fan as well) just because I don't like the look of the Heat sink sticking out the side of the control box. If this is a bad idea I'll deal with the heat sink outside of the box, but the box is 12x10x6 and I am not putting much in it at this point.

Any advice is greatly appreciated!

Thanks!
Mike

 

[BrunDog]

You can't (shouldn't) power 120V devices without a proper neutral, which a dryer cord does not have.

 

[doug293cz]

Hey all, I've been reading E-HLT threads for a few weeks now and I am very close to starting the build on my PID control box. So far I have a 3 prong dryer outlet not GFCI protected in my basement. I have installed the 5500w 240v Heater element into my HLT. I'm far from an electrician and my setup isn't exactly like anyone else's that I've read so far so I'm a bit nervous about this build and want to make sure I do everything safely and correctly. I am hoping you guys can offer some advice or tell me if I'm screwing anything up before I burn down my house.

1. First things first, I'm going to Home Depot tomorrow to get a 30a GFCI breaker to replace my existing breaker.
2. Coming into my control box will be a 3 wire 240v dryer cord, 1 of the 120v hot wires from the cord will go to my PID, which will then go to the SSR and then into one pole of a DPST switch and terminate into a 3 prong dryer outlet inside my control box. The other hot wire will go directly to the other pole of the DPST switch then terminate in the same dryer outlet in the control box. I think this should give me the ability to turn off my heater element while still monitoring the temp as the wort is chilling. I have read about the "ramping issue" with the element switched off, but I think it's a good idea to have a way to kill the heater if I want to. I suppose I could also just set my PID to 50 degrees when chilling, thoughts?
3. The ground/neutral wire from the cord will go to a grounding bar which will ground my PID, SSR and outlets inside the control panel.
4. I will also tap into one of the 120v hot wires and power a couple 120v switches/outlets to control the Herms pump.
5. I'm considering installing the SSR with the Heat sink inside the control box with vent holes drilled in the side (possibly may get a small PC fan as well) just because I don't like the look of the Heat sink sticking out the side of the control box. If this is a bad idea I'll deal with the heat sink outside of the box, but the box is 12x10x6 and I am not putting much in it at this point.

Any advice is greatly appreciated!

Thanks!
Mike

Item 3 will prevent the GFCI from working correctly. The GFCI will not be able to detect leakage from hot to the ground circuit, if the ground and neutral are common after the GFCI, which is what you propose. You won't have all the protection you should have if you do this. This can be corrected by putting the GFCI in a spa panel downstream of the dryer outlet. Inside the spa panel you connect the ground and neutral before the GFCI breaker. This will allow the GFCI to detect leakage to the ground circuit, as well as the other faults it detects. The diagram below shows how to wire a spa panel to turn a three wire feed into a four wire feed. Note that this method does not meet current electrical codes, so it cannot legally be part of the structure wiring (i.e. it must be unpluggable, but that shouldn't be an issue since you're coming off a dryer outlet.) There is also debate on whether or not this method provides adequate safety. I believe it does, as long as the total 120V current draw from devices after the spa panel is less than about 5A (a Chugger pump draws 1.4A), and the total wire length between the main breaker panel and the spa panel is less than about 100 ft.



Here is a schematic for a control panel design that sounds like what you want to do. The fuses are required if you are using a spa panel to convert a three wire feed to four wire, as they are what will limit the current in the neutral leg to safe values (in addition to protecting the finer wires within the control panel.)



For item 5, having the heatsink inside the enclosure significantly reduces it's effectiveness. The SSR can dissipate up to 35 watts in operation, so it needs adequate heatsinking. If you want to install the heatsink inside the enclosure, you will need inlet vents, outlet vents, and a fan. The fan should be mounted over the inlet vents, blowing into the enclosure, and the heatsink should be mounted close to the fan, with the air flow from the fan parallel to the fins on the heatsink.

Brew on

 

[MFigz]

Thats some incredible information, and it looks like I'll save myself around $40 on the spa panel vs the GFCI breaker. I saw some posts about the spa panel but I kind of skimmed past them because I didn't think I needed it... The way you explained it makes perfect sense! I have a few follow up questions.

1. Will this spa panel work for me? http://www.homedepot.com/p/Eaton-50...el-with-Self-Test-2P-GFCI-BR50SPAST/206696172 I don't see the second grounding/neutral bar, although it may be hidden in the picture.
2. For the spa panel diagram, there is no wiring color code so I just want to make sure I understand everything correctly. Blue and Red are hot, yellow is neutral and green is ground? I'll be routing the white wire that is part of the box to what I expect is the neutral pole on the GFCI breaker?
3. Now onto the Control box diagram. It looks like the element switch is installed before the PID. I originally was planning on installing the switch after the SSR so I could kill power to the element while still monitoring temp on the PID as the wort cools. Is this a bad idea?
4. Is there any reason I can't use 16 ga wire which I have a lot of in place of the 20 ga which I would have to buy? It's not a big deal either way, but if 16 ga works just as well, then I'll use what I have.

Thank you so much for this help. I have gone from feeling very nervous to very excited now!

Thanks!
Mike

 

[doug293cz]

Thats some incredible information, and it looks like I'll save myself around $40 on the spa panel vs the GFCI breaker. I saw some posts about the spa panel but I kind of skimmed past them because I didn't think I needed it... The way you explained it makes perfect sense! I have a few follow up questions.

1. Will this spa panel work for me? http://www.homedepot.com/p/Eaton-50...el-with-Self-Test-2P-GFCI-BR50SPAST/206696172 I don't see the second grounding/neutral bar, although it may be hidden in the picture. Yes that spa panel will work.
2. For the spa panel diagram, there is no wiring color code so I just want to make sure I understand everything correctly. Blue and Red are hot, yellow is neutral and green is ground? I'll be routing the white wire that is part of the box to what I expect is the neutral pole on the GFCI breaker? Correct
3. Now onto the Control box diagram. It looks like the element switch is installed before the PID. I originally was planning on installing the switch after the SSR so I could kill power to the element while still monitoring temp on the PID as the wort cools. Is this a bad idea? The 3032 switch only kills power to the SSR and element. The DSPR remains on (it's always on when the control panel is plugged in), so you can monitor temp when the element switch is off. I like to put power switches as close to the incoming power as the design allows. That way there are fewer things "hot" in the panel when the switch is off. Just a design philosophy I follow. There are a lot of panels out there with the element power switch after the SSR (especially since P-J tended to design that way.)
   
4. Is there any reason I can't use 16 ga wire which I have a lot of in place of the 20 ga which I would have to buy? It's not a big deal either way, but if 16 ga works just as well, then I'll use what I have. You can certainly use 16AWG instead of the 20AWG. You could even use 10AWG everywhere, but that's a pain in the butt. You must use 10AWG where shown however.

Thank you so much for this help. I have gone from feeling very nervous to very excited now!

Thanks!
Mike

Brew on