Enclosure For My New PID Temperature Controller,,, ? HELP!

[SweetMk]

I have been looking for an enclosure for my new PID temperature controller that arrived in the mail today.
After searching Lowes website for a half hour,, I found what might be a nice candidate,,

It is called;

"2-Pole Light Duty Enclosed Disconnect" ,, or something like that,,

The box has several knockouts, so making holes will be easier,
I think most of them can accommodate a circuit breaker, right off the bat, so that may be taken care of,,

The cheapest one did not list dimensions, but all the others were big enough to hold the PID controller,,

The lowest cost one is only $10,, the "expensive ones" range up to about $15,,



I will have to look at them at the store, before I make a final decision as to which to go with,
If I find one big enough, I might get one that the Lee Metal Melter can just sit on the top of the enclosure.
That would make a nice compact package,,
Am I barking up the wrong tree for any reason, or does this steel box seem like a good option??

Save me from myself,, if necessary!!

[BamaNapper]

I looked at the Lowes site. I'm confused. The description says molded, which I assume would not be metal. But the pic looks metal. Personally, I'd prefer metal since it can then be used as the heat sink for the SSR. The pic also shows what appears to be a breaker, but the description says non-fusible. The switch shown is probably just a knife switch, not a breaker. Also, the description says 1" knockouts, so it's not the ordinary 1/2 or 3/4" cable strain relief I have laying around in my electrical bucket. This box is made for outdoor A/C units so it's designed for armored cabling hookups.

Like you said, I'd have to go to the store and scope it out first. For dimensions and a little more info go to grainger.com and search for part#DPU222R. They should also have a link to the Eaton spec sheet.

[SweetMk]

I looked at the Lowes site. I'm confused.

The description says molded, which I assume would not be metal.

Yea, there is a lot of confusion on the Lowes website,,
the spec sheet says "Metallic" for the "Casing Material",, WOW,, what a word choice,,
Metallic could mean plastic that looks like metal,, LOL!!

Also, the case does not look like it would have a flat "TOP" if it were laying on its back,,
so, that one might not be perfect for setting the Metal Melter of top of it,,

I guess i gotta stick a magnet in my pocket, head to Lowes, and try to pick one out,,

I have a couple extra 15 amp breakers for the GE enclosure,, but,
a different brand of box PLUS a new breaker would cost less than the GE box,,

I did find a piece of copper bus bar that measures 2X3X1/4" in my scrap materials bin,,
That should be a great heat sink for the SSR,,
I even have a tube of silicone grease,,

[Hossfly]

I put mine in a box like that. The metal is very thick but can be cut with a Drimmel with an abrasive wheel. Just take your time and wear safety glasses. Good heat sink for mounting SSR with paste on back. Very sturdy.

[PNW_Steve]

How hot does your SSR get?

I used a 40A SSR and have monitored the temperature and it barely gets above ambient temperature.

I was shopping metal boxes to accommodate heat sinking the SSR. After running naked for several sessions, I don't think that I need a heat sink.

I am seriously considering a 3D printed enclosure. The only hang up there is that I don't have one yet...... All of that exposed wiring is beginning to look like a safety hazard....... If I don't get a 3D printer soon I will probably be electrocuted!

What do you think? Will my wife buy it?

[SweetMk]

How hot does your SSR get?

If I don't get a 3D printer soon I will probably be electrocuted!

What do you think? Will my wife buy it?

My SSR is still in the shipping box, never connected (it just came yesterday in the mail)
so the temp of the SSR it is at is room temperature,,

As far as the printer,, I ALWAYS use "Life or Death" as my reasoning to get my wife to let me spend $,$$$,,,

[stumpjumper]

Dont know if my picture will show up

[stumpjumper]

The ssr would have fit inside the box, I was afraid of the heat so I put them underneath the box. I bought them at lowes!

[Hossfly]

I feel very little heat from my SSR, its mounted inside of the box with heat sink past under it. I think its doing its job very well since 2HRS sessions with the Lee 20# pot just barely can feel some heat right at the location of SSR thru back of metal box. Been working perfect for 2 yrs. now. No fan just contact with box metal.

[Conditor22]

I just gutted a LARGE computer power supply for the second one I made

[BamaNapper]

An SSR should not get very warm unless you're running a seriously power hungry device with it. Most SSRs we're using with our lead pots are 40 amp devices. That's about 5,000 watts. By comparison, the LEE 20# pot uses 700 watts (about 6 amps). So we can make a couple assumptions and do the math. Typical voltage drop across the load side of a cheap SSR is going to be about 1.5V, but that's at max current. If we're running only 14% of max (700/5000) the voltage drop should be at most .21 V (1.5V * 14%). So the power dissipation of the SSR would be about 1.26 watts (6 amps * .21 volts). That's not much heat to dissipate. In comparison, that's less power than my iPhone 5 has to dissipate while I'm playing Sudoku.

So, is it worth worrying about a heat sink? The answer ... Probably not, but it doesn't hurt. But if I have to mount the SSR anyway, why not mount it to something metal?

[Larry7293]

Why not use a wooden box?

[SweetMk]

I told my neighbor about what I was doing, and he said he had some left over Square D 15 amp breakers.

I went to Lowes, and found a Sqiare D 70 amp box that would hold two breakers
I got the breaker from my neighbor, and test fit the control and SSR in the box.

Here is a pic of the $13 (after vet discount) box,, with all the components inside.
There are 12 pre-punched knockouts, so I can use a couple for wires, and enlarge one to square for the controller,,

None of them were suitable for me to set the pot on the box.

[bruce381]

I feel very little heat from my SSR, its mounted inside of the box with heat sink past under it. I think its doing its job very well since 2HRS sessions with the Lee 20# pot just barely can feel some heat right at the location of SSR thru back of metal box. Been working perfect for 2 yrs. now. No fan just contact with box metal.

Yeah me to a 40A SSR and 2-3 hrs on lee pot is warm ish. Is on a heat sink to metal box.

[slim1836]

Attachment 270841

I too used a computer power supply box for my P.I.D.

Slim

[HATCH]

Not sure if that is deep enough.

The PIDs I build are 1/32 din size.
I have been trying different enclosures but my standard metal enclosure cost me $16.
Been looking at some cheaper ones both plastic and metal but those are still $12.

Typical lead furnaces draw about 7 - 10 amps.
Typical SSRs are rated for 25 or 40 amps.
Your not going to get much heat out of them controlling a standard lead furnace(lee pro 420,pro melt). Something else to consider is that the furnace is 120v and plugs into a standard wall outlet then it’s not gonna pull more then 15 amps anyway. So by using a 25 amp ssr you aren’t overworking them.

I see people making the effort to use heat sinks on their PID designs but it’s a waste of money if your ssr is rated 25 amps or larger as you don’t generate any heat. If you were to use a 10 amp SSR then yes I would use a heat sink as your at almost 80% of rated power for the SSR.


For my design, I have been using the enclosure as a Heatsink because it’s metal and haven’t had any issues. But on my Master Caster control panels are now plastic and don’t have heat sinks. The 120v pot pulls 13 amps and I haven’t had any issues with heat induced failures.

YMMV


Sent from my iPhone using Tapatalk

[SweetMk]

Why not use a wooden box?

If I were to build it out of wood,,
the end result would look like a 30 year old, well weathered bird house!! LOL!!

[Mal Paso]

How hot does your SSR get?

SSRs generate just over 1 watt of heat for every Amp Controlled but only while the SSR is ON. On a 20-25 pound pot the SSR will produce 7-10 watts of heat (like an old fashioned night light) until the pot reaches temperature then 1-2 watts average.

[dimaprok]

I build my inclosure out of some nice finish plywood. Why? Well it's a lot easier to work with wood. Since then I found and bought some really nice metal boxes at local scrap yard for few bucks, I picked up a couple for future PID builds, got all parts too, just need to build it. Need to find pictures to post here.

[JonB_in_Glencoe]

The first PID I built, I used a small cage type enclosure I got free from the jobsite scrap bin...I've never seen another one like it.
So, if some day I build a second PID, which is likely. I have acquired (for free) a old computer power supply with a "large enough" metal enclosure, like Conditor22 and Slim have used.

The first one I build with a 40A china SSR, it doesn't get hot at all, no need for extra heat sinking.