Industrial Scr

HI
what is the method to check HOCKEY PUCK SCR? Thank you

You'll need to be more specific. You probably haven't recieved any responses because the question doesn't make sense - at least to me.

PERSPOLIS said:

HI
what is the method to check HOCKEY PUCK SCR? Thank you

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Do you mean one of these?

http://darrahelectric.com/articles_trouble.htm

JasonWade said:

http://darrahelectric.com/articles_trouble.htm

Click to expand...

Follow these instructions completely for the large ones. You MUST compress the puck close to what is in the original fixture. You might be able to test in place if the connections are such you are able to isolate each one. We have some large ones that cost around US$1000 each so proper testing in important.

A high current Hockey Puck (over 25 amps) is built with back-to-back SCR's. Each SCR conducts a half phase. The Hockey Puck is called an SSR (Solid State Relay).
The easiest way to check SCR's is with a neon bulb. Make sure it's rated for the proper voltage. You can use one of those yellow neon testers as long as you can see both posts inside the bulb.

For this test, we'll assume a simple heater circuit. Power is applied, contactor is pulled in, and SSR is off. In this condition, line voltage will be across the SSR.

Connect the neon directly across the SSR output terminals. When the SSR is OFF, both posts will glow. If one SCR is shorted, then only one post will glow.
Heater commanded on=neon off. (If on, SSR is open)
Heater commanded off=neon on. (If off, SSR is shorted)
bad SSR = half neon on.

If you can't find a tester, then buy a neon bulb with integral resistor from Radio Shack. I think they still sell them. The resistor should be about 47K for 120 volt, and 100K for 220-240 volt. You can use the 240 volt version for testing 120 circuits.

This also works for DC SCR's, except only one post will glow-no glow depending on polarity.

By hockey-puck I'm assuming you mean a round single SCR element.



Take a look at the attached PDF. It outlines the test method for a hockey puck SCR using a multimeter and a 6V battery to gate the semiconductor. There is a circuit diagram of the test setup on the last page. As has been stated, you MUST compress the puck because it contains an internal compression contact and does not function unless properly clamped in a heat sinking device. For testing only purposes a couple of aluminum plates and a bench top vise (or a C clamp) is sufficient - just make sure you have some insulators in place.

HI
Thanks guys for the positive response.Indeed all solid information provided that I needed most once again thank you all.

keithkyll said:

A high current Hockey Puck (over 25 amps) is built with back-to-back SCR's. Each SCR conducts a half phase. The Hockey Puck is called an SSR (Solid State Relay).
The easiest way to check SCR's is with a neon bulb. Make sure it's rated for the proper voltage. You can use one of those yellow neon testers as long as you can see both posts inside the bulb.

For this test, we'll assume a simple heater circuit. Power is applied, contactor is pulled in, and SSR is off. In this condition, line voltage will be across the SSR.

Connect the neon directly across the SSR output terminals. When the SSR is OFF, both posts will glow. If one SCR is shorted, then only one post will glow.
Heater commanded on=neon off. (If on, SSR is open)
Heater commanded off=neon on. (If off, SSR is shorted)
bad SSR = half neon on.

If you can't find a tester, then buy a neon bulb with integral resistor from Radio Shack. I think they still sell them. The resistor should be about 47K for 120 volt, and 100K for 220-240 volt. You can use the 240 volt version for testing 120 circuits.

This also works for DC SCR's, except only one post will glow-no glow depending on polarity.

Click to expand...

I think you are referring to a triac, 2 SCR's in parallel. That is used on AC control power circuits. An SCR, silicon controlled rectifier, controls a half of the sine wave producing a DC pulse depending on the gate signal. Multiple SCR's in half or full wave bridge can produce varing DC power.

See: http://www.allaboutcircuits.com/vol_3/chpt_7/5.html

An SSR, solid state relay is a slightly different device, see triac used to control AC devices. Typically used as a relay for on/off functions of heaters and such without the mechanical problems of a typical relay.

Personally hate to debate things like this with keithkyll but have to agree with John, a hocky puck is just an SCR, nothing more. They are majorly used in welding applications.

Another troubleshooting guide: http://darrahelectric.com/articles_trouble.htm

IMO Keith gave a great answer because I learned something from his post that I didn't know; that trick with that neon bulb is something I'll have to remember. And, if you think about it, the same concept will work on an SCR as well for testing without unclamping the puck from the heat sinks, except you will just have one post glowing or no posts glowing. After reading that I thought of making a test box with some resistors and two multicolor LEDs to make testing of our SCRs easier on Bubba an his crew. So have a beer on me Keith, and thanks for showing this old dog a new trick.

Thanks Alaric. The neon will tell you if an SCR or SSR is good or bad, as you pointed out. It needs a minimum 60-90 volts or so to fire - no help in low voltage circuits.
To Ron and others - never hold back from disagreeing with me. Accuracy is the most important part.

John Soltesz said:

I think you are referring to a triac, 2 SCR's in parallel...

Click to expand...

A typical SSR is built with a Triac (single, AC device) up to 25 amps. 40 amp and higher use back-to-back SCR's (DC device) to accomplish the same function.
When I saw the term 'Hockey Puck', I saw a square black SSR. I never knew those big round ones were called hockey pucks too. I didn't know you had to clamp them down to bench test.
I learned something new too.
PERSPOLIS never said what hockey puck he was refering to. Most likely, he wasn't talking about an SSR.

Do you suspect an intermittent problem with an SSR or SCR? Put a neon (with resistor) across each device, then power up. When things start acting up, the lights will tell you what's wrong.