HI
As for the time to heat up my oven it take about 30 minutes for the first heat up to temp. About 5 to 7 minutes to reheat after adding parts. This is controlled by the PID it shows set temp and actual temp. So you can see with the temp is in the oven at all time. The time starts when the oven has returned to the powders bake temp. I have a small vent but no air movement device in the oven.
Have it all hooks up together.
The PID is powered by 110 vac has temp probe input and power out to a relay or SSR. See attached wiring diagram. Both of these are small but the ssr can handle all the current you would need. The SSR controls the power to the heating elements.
I had a HF gun and still have a caswell 50KV gun it does a very good job. Simple to clean and use. Most of the low priced guns are the same looking the difference is the power supply. If you doing things with inside corners or applying 2 coats you need to bigger power supply then HF’s gun.
Basically the gun moves the powder inside the gun (fluffs it up) then blows it out. Along the way it puts an electrical charge on the powder so it sticks to the parts being sprayed. The power supply has a ground clamp that you attach to the parts or the hanging hook. I use a big cardboard box to put the parts in when I spray them to control the powder from getting all over the place. You can reclaim the powder that drops to the bottom of the box.
Have fun
Tom
Everlast PM256
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Longevity Force Cut 80I
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ect, ect.
DAC45 
