Turned the oven on for 1st time - Fireworks!

[chromo]

I don't know anything about the SSR but many electronics don't take much time at all to fry with out a heat sink. For instance you may normally fry a computer CPU in a few seconds if you turn on the computer without a CPU heat sink.
I saw someone do that once also, his heat sink clip was not on soild and as he turned on the system the heatsink popped off. He did not even make it into the system bios before the CPU fried.

If your SSR says it should have a heat sink use a good one, 10 minutes is a long time, for some electronics 1 minute is a long time. Even with a fan.

[CarWiz]

Make sure you have the heaters wired in parallel and feeding them with 240v.

A common mistake is to wire them in series or use only 1/2 the 240v circuit. Both sides of the hot legs are used for 240v. The common is NOT connected to the heaters. Were the heaters glowing red?

A heat sink is a good idea no mater what the amp rating of the SSR might be. You need to check the specs of your SSR. Some gain their rating by having a very large heat sink. Without it, it may be rated at 20A or less. You're drawing over 40A!

[rowdenboyz]

I have the elements wired in series with both hot legs. As for the SSR, it is rated 75A at 240VAC. I ordered a new one yesterday that is rated to 45A at 240VAC and has a heatsink. We will see how it works.

[CarWiz]

RE-READ MY FIRST LINE!

Do NOT wire the heaters in series! You'll only get about 960 Watts--Total output. The heaters should glow red in a couple of minutes.

Do NOT exceed 75% of the SSR rating for heater elements. You need at least a 60A SSR and heatsinked. Check your SSR specs!

ADDED: The metal on the bottom of the SSR DOES NOT COUNT as a heat sink. Follow the specs of you heat sink. Most require 36 sq. inches of heat sink and the enclosure box makes a POOR heat sink.

[Crimson]

where would one get a heat sink for an SSR??

[BottleFed70]

Originally Posted by Crimson

where would one get a heat sink for an SSR??

Most places that sell SSR's also sell the heatsinks for them.

I plan to use some old computer CPU heatsinks that I have laying around, they should be more than enough. Especially if I use the included fans.

[CarWiz]

I found an old aluminum street sign at the salvage yard I was cutting up for heat sinks until I found some scrap 2" copper pipe. I slit the pipe lengthwise and flattened it out. Copper is best (unless you can find silver) but 1/8" aluminum sheet works well. Be sure to use a thermal compound under the SSR. Or like BF, use computer processor heat sinks--They're more compact and most have a fan.

[rowdenboyz]

RE-READ MY FIRST LINE!

Do NOT wire the heaters in series! You'll only get about 960 Watts--Total output. The heaters should glow red in a couple of minutes.

Do NOT exceed 75% of the SSR rating for heater elements. You need at least a 60A SSR and heatsinked. Check your SSR specs!

ADDED: The metal on the bottom of the SSR DOES NOT COUNT as a heat sink. Follow the specs of you heat sink. Most require 36 sq. inches of heat sink and the enclosure box makes a POOR heat sink.

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Last edited by CarWiz : 07-16-2007 at 09:37 PM.
I meant Parallel, not series. They do glow red in a few seconds. Thats not the problem anyways!

[CarWiz]

That's ok, I meant Seconds too.