Exploded SSR / Loud Pop / PLEASE HELP

[dyqik]

The pic of the glowing red element is still less than 1500˚F. You want white light you need to be a lot hotter.
Brew on

Although brewing with white light may put you at risk of skunking your beer.

 

[dyqik]

Does this also include the feeder wiring?

This is the NEC code for permanent wiring within the walls of a building running from the breaker to the outlet or permanently wired load. You are good to use the full rated current continuously for up to three hours, but should use a higher rated circuits for permanently wired loads that are designed to run for more than 3 hours continuously.

Wiring, e.g. in a control panel, that can be disconnected with a plug and socket isn't subject to exactly the same rules (which is why you can wire a plug-in lamp with 18g and connect it to a 15A circuit), as the wires aren't permanently attached to the structure, but it makes sense to use the same ratings there to keep things simple.

 

[dyqik]

240v is not what is used for calculation.. The acceptable voltage range is 220v -240v... (110v-120v for 115v)..

So calculations are done using the 'ideal' target voltage of 230v.. That is what the generating plant seeks to deliver to your premises... Load on the system (or lack thereof), voltage loss due to long wire runs, etc. can affect the system voltage, both at delivery point, or at point of use... If you put a meter on your service, and watch it throughout the day, especially in summer months when all your neighbor's A/C is running (or your own), you'll see the voltage delivered to your service vary quite a bit....

The power ratings of heating elements are specified at 240V, not 220V or 230V. For current calculations for the heaters we use in brewing, you need to use 240V, not 230V, to determine the resistance of the element, and realize that the delivered power is likely less at 230V.

There's also a bit of variation within each production run of elements and between production runs.

My kettle element reaches 5450 W at 240V (measured with current/voltage/power meeting I built into my simple SSVR controller). Typically my supply voltage varies between 237V and 242V.

 

[Bobby_M]

The power ratings of heating elements are specified at 240V, not 220V or 230V. For current calculations, you need to use 240V, not 230V, to determine the resistance of the element, and realize that the delivered power is likely less at 230V.

Yes. Every element I've had in my hands is marked as power at 240v. Actual power is derived by actual voltage.

 

[passedpawn]

Here's the measurements I made on my system a few years ago. This is with a Camco 5500W element

233.5VAC measured with multimeter.

22.01 measured with clamp-on ammeter.

So that's only 5139 Watts of heat from my element.

 

[Gavin C]

Right. With incandescent, it's a 10x change in resistance. Pretty impressive. Brewing element shouldn't exceed 212F. Shouldn't Depends on how you clean your element.

http://www.youtube.com/watch?v=nKG3UjT0Wz4

Love it!

I've heard you mention this method of cleaning before. How long are you powering it dry there? Few seconds?

Does the element flex as it heats in the video. I didn't know they did that. Great video.

Not sure I'd be brave enough to try this. (It's moot now as I don't use electric but one day I will.)

 

[passedpawn]

Love it!

I've heard you mention this method of cleaning before. How long are you powering it dry there? Few seconds?

Does the element flex as it heats in the video. I didn't know they did that. Great video.

Not sure I'd be brave enough to try this. (It's moot now as I don't use electric but one day I will.)

Just a few seconds after it gets red. That's all it takes. Everything turns to ash. Regarding that slight movement of the element when heated, I guess that's the coefficient of expansion of the materials at play there.

 

[Gavin C]

Just a few seconds after it gets red. That's all it takes. Everything turns to ash. Regarding that slight movement of the element when heated, I guess that's the coefficient of expansion of the materials at play there.

Makes sense.

I clean my grill in a similar lazy manner. Turn all all the burners for 10 minutes or so with the lid down.

Dracarys!

 

[r8rphan]

The power ratings of heating elements are specified at 240V, not 220V or 230V. For current calculations for the heaters we use in brewing, you need to use 240V, not 230V, to determine the resistance of the element, and realize that the delivered power is likely less at 230V.

There's also a bit of variation within each production run of elements and between production runs.

My kettle element reaches 5450 W at 240V (measured with current/voltage/power meeting I built into my simple SSVR controller). Typically my supply voltage varies between 237V and 242V.

Well, if you want to get technical about the calculations of 'appliances' (I was speaking to the code), then you are supposed to have it UL tested, whereby the UL inspector will make the call if it's safe or not, and the appropriate UL label applied..

But now we're 'really' splitting hairs, as no one in their right mind would spend the 25k-75k it costs to get a UL listing these days on such a thing (unless they were planning on manufacturing them).. lol

The bottom line is, the 30A DPDT switch is perfectly fine to use for this application..

Calculating at 240v (which is not standard practice for things that the NEC applies to), makes this even 'more' true... not less...

The discussions here are using the NEC as a guide as to what is considered safe... They are generally 'way' conservative in what is safe.. I know the utility does not have to restrict itself near as much.. They often use much smaller wire coming to the service than we are required to use for the service drop...

My purpose in jumping into this discussion at all was to show that he was not really in danger from the short (as it is a GFI protected system), and that 30A DPDT switch is 'fine' for this purpose...

 

[r8rphan]

Yes. Every element I've had in my hands is marked as power at 240v. Actual power is derived by actual voltage.

That's the device's rated voltage.. Anything 'above' that is 'beyond' the devices rated voltage and considered improper usage...

If you are experiencing more that 240 volts at point of use (or even at service entrance), I'd contact the utility and have them fix it... (like wise if below 220v)

 

[r8rphan]

The question is at what voltage does the element actually deliver it's rated power? At any lower voltage, it will deliver lower power, and draw less current. If the element can deliver rated power at less than the maximum possible line voltage, then power at max possible voltage needs to be determined in order to calculate max possible current draw. A possible complicating factor would be if the element had a negative temperature coefficient of resistance. To my understanding, the elements we use have small positive temp coefficients, so we don't have to worry.

Brew on

Exactly! Rated power/voltage are 'maximums' Rarely will that be the case...

 

[r8rphan]

Either could be used. I don't think there is any benefit to using a breaker for the PID fuse. It might be advantageous to use a breaker for the pump outlet, as it is more likely that the pump could overload without an actual permanent fault condition.

Brew on

Until you are in the middle of a brew and don't have a spare fuse... (Let the cursing begin).. lol


I was just curious what you used...

Fuses sometimes just get weak and 'go'... (Then again, so do breakers)

 

[r8rphan]

Popping in for one last note, his idea absolutely would work, it doesn't matter if the contacts on the controller are NO. He just needs to use a pilot relay with the coil voltage for the contactor going through the NC contacts of his pilot relay. I drew a mock up a few posts back and attached as a PDF.

a lot easier if they were just NC to start with though...

 

[augiedoggy]

Ok so I'm pretty shaken up. I knew I was no electrician going into this but I thought I had it wired correctly. I'm fine. Did not receive any shock.

I'm building a very simple electric HLT. I must have wired something wrong b/c when I flipped the switch on my project box, my box jumped from the table and the SSR inside was fried. The 30 amp breaker in the main panel had tripped but the 50 amp GFCI had not. Feel free to tear me a new one. I'm ashamed of myself and pretty flustered.

Here's my wiring diagram

Here's my list of materials.
http://www.lowes.com/pd_591488-427-3032WZ_0__?productId=50179201#img

http://www.amazon.com/gp/product/B0087O6T10/?tag=skimlinks_replacement-20

http://www.lowes.com/pd_423568-43469-2203___?productId=4013827&pl=1&Ntt=30+amp+dryer+outlet

nevermind already pointed out

 

[augiedoggy]

No, but a light bulb is a load and you stated you wouldn't use a switch to power a load. So what you are implying is that at some point of power consumption there is a cutoff where you should not use a switch and instead use a contactor regardless of whether the switch can handle that load or not? Can I ask what this magic number is?

I would like to know why using a breaker SWITCH is ok but using another properly rated switch isnt? is a breaker not a direct mechanical switch?

 

[augiedoggy]

Here's the measurements I made on my system a few years ago. This is with a Camco 5500W element

The 4500w element I bought from spike that I use in my only draws 4026w at the full 240v and my HLT 4500w element draws over 4400w max at the same voltage. So while the max draw is always equal to or less than the max rated output it can vary quite a bit from element to element due to manufacturing tolerances. most 5500w elements will draw around 22-21 amps with normal voltages found in 240v household wiring. with 23a being the max.

 

[r8rphan]

I would like to know why using a breaker SWITCH is ok but using another properly rated switch isnt? is a breaker not a direct mechanical switch?

They're both okay...

 

[thekraken]

Just a few seconds after it gets red. That's all it takes. Everything turns to ash. Regarding that slight movement of the element when heated, I guess that's the coefficient of expansion of the materials at play there.

How often do you do this? Ever caused any problems? Noticed accelerated 'wear'?

 

[passedpawn]

How often do you do this? Ever caused any problems? Noticed accelerated 'wear'?

Maybe a few times a year. I brew pretty often, and usually the pbw soak does the trick. But occasionally (not sure why) I get accumulated hard stuff on the element in my boil kettle, and I'd have to brush and scrape to get most of the crud off. No more scraping now

I've only replaced one element since I went electric in 2009. That element died before I started doing this. It's still possible that numerous dryfire events caused its failure, who knows. It developed a hole at the base of the element.

As far as I can tell the elements I've been doing this to are like new. I can quickly replace them if there was an issue. So far so good.