Newb needs help

[jgwood]

I have been lurking for a while.Finaly building my oven it is 6 ft long 6 ft tall 3 ft wide inside I have 6 of these <NEW!> Electric Oven Bake Element (GE WB44X200) - eBay (item 400057919989 end time Aug-23-09 13:22:21 PDT) and i will run it with this controler PID Temperature Controller Fah/Celsius + 40A SSR - eBay (item 200367467222 end time Jul-28-09 14:44:25 PDT) i whant to use 2 solid state relays like these New in Box Solid State Relay SSR 24-480V AC, 25A - eBay (item 370228000904 end time Aug-09-09 20:00:55 PDT) i know i have to run the eliments in parellel along with the 2 relays.my main question is how to power it up to the set620 .Due i just hook the power right up to the controll or is there a better way
Thanks
Gregg

[ed_denu]

A couple of things to consider.

The elements you reference have no wattage listing, so knowing their requirements(such as amperage) is going to be a guess. If you have these already and can do an ohms check on them then their wattage can be computed.

The pid you reference comes with an ssr, but then you reference other ssr's?

The 25A ssr's are probably not going to work if you intend to attach 3 elements. Assuming the elements are around 2500 watts(a guess), then 3 elements are going to consume 31 amps, much more than the capacity of this ssr.

I'm not sure about your power question. The pid needs power to function and typically you should have a master disconnect to the oven. A small toggle switch can also be placed between the source and the pid.

Lastly before proceeding insure that your electrical service is capable of handling your planned oven and elements. If you don't have a 100 amp service you are probably going to have problems.

[jgwood]

After posting i decided to go to eather 3 ssr with 2 elements or finding 40 amp ssr.I have a 200 amp service to a building that is 23 by 23 with a 16 by 12 addon so i have more than enough power.So the pid will handel the 220 power to it was what i realy need to know
Thanks Gregg

[ed_denu]

After posting i decided to go to eather 3 ssr with 2 elements or finding 40 amp ssr.I have a 200 amp service to a building that is 23 by 23 with a 16 by 12 addon so i have more than enough power.So the pid will handel the 220 power to it was what i realy need to know
Thanks Gregg

The pid can handle input power from 90-260 vac. The pid does not handle the element load, that's the job of the ssr's, which would switch one leg of the 240 volt circuit to control the on/off cycle.

The pid(40ma ) may be able to handle 3 ssr's but without seeing the trigger current specifications for the ssr, you can't be sure. And without knowing the wattage rating of the elements you can't be certain that a 40A ssr would be sufficient for 3 elements. If they're around 2500-2600 you are on the edge for 3 elements, anything over that would be excessive and probably lead to a short ssr life span.

[jgwood]

ED so it would be best to run 3 ssr with 2 eliments each at say 30 amps a ssr.
I have so much going on and have to get this oven built.I dont habve time to read every thing so any help is aprechated.Can i use the 40amp and 2 of the 25 or is it best to have 3 of the same ssrs
Gregg

[ed_denu]

Gregg, A quick question. Have you purchased the elements yet, and if so can you do an ohms(resistance) check on them. Without knowing their wattage, it's really just a guess as to what will work.

You can use different capacity ssr's, but can you answer the above question?

[mhyde71]

where are we at with this?? i am like on the edge of my seat... Got me curious? as I am approaching to be in same position.
oh! and pic's are always cool too!
Just got done talking with buddy... gave me some ideas, but like to see this play out as well.
very interesting!
matt

[jgwood]

A up date i have been busy with my day job.The eliments were orderd a few weeks ago along with the controler with made me post the questions.I have orderd 2 more ssrs .I have contacted my nices husband who works for Johnson controls.And he is looking at every thing so far He has said it is pritty straight forward just run the ssrs in parelel then run the eliments the same and every thing should be fine .We have also talked a bout running 2 pids for better controll and being able to shut half down if not needed.I have picked up my steel for the shell have to pick up a few more studs and my insulation thursday so hope fully i will have time to start .Puttiong the rest of it togeather this weekend.I have my service pannel inspection on friday so hope full the power will get hooked up pretty quick after that.I am hoping to have it fired up in the next 2 or 3 weeks.
Gregg

[tedsfab]

sorry to butt in here . but with the ssr's and controller doesnt it put extra strain on the controller to trigger them ?


i only ever used ssr's 1 time and that was enough for me like the magnetic relays alot better

[ed_denu]

sorry to butt in here . but with the ssr's and controller doesnt it put extra strain on the controller to trigger them ?

That's a reasonable question. Many of the pid's list around a 40ma capacity on the ssr relay. The ssr's I've looked at usually list a trip or current draw of 7-12ma, so in theory one should be able to control 2-3 ssr's from a single pid without problem. The only question is that many of these pid's come from China or elsewhere and the documentation is lacking so you don't know if the 40ma number is a peak or continuous load rating.

I know people have posted that they have used 2 ssr's in their builds, so I would think using 2 is ok, 3 maybe?