Dc rectifier

[wozz]

Bare with me here electronics isn't my thing as you can tell.

I replaced a faulty one of these the other day which supplies dc to a brake on top of a motor. 400v ac to 180vdc.

I had a wiring diagram flashed into of me which showed two diodes ( I take it for half wave) and two other symbols which were not immediately obvious to me. It mattered little part replaced all good. But what I want to know now is what would the two other symbols be? Would they have been for voltage regulation like a Zener diode?

Also so would there have been a way to prove the item was faulty through testing rather than function?

Cheers for for any input.

 

[plugsandsparks]

can you describe the symbol or photograph it and pop it up ?

 

[wozz]

Sorry mate literally only clamped my eyes eon it for two seconds , and doubt I will be able to get hold of another for a while.

From I memory one phase come in went through a diode and then on to the component in question then it looked like it left the unit as dc,
other phase was exactly the same.

 

[SheffSimon]

Sorry mate literally only clamped my eyes eon it for two seconds , and doubt I will be able to get hold of another for a while.

From I memory one phase come in went through a diode and then on to the component in question then it looked like it left the unit as dc,
other phase was exactly the same.

Bit like one of these... http://download.sew-eurodrive.com/download/pdf/9PD0049.pdf

The other symbols look like thermistor symbols with a bit extra on. Dont think they are though.

 

[wozz]

thats the one mate cheers.

 

[plugsandsparks]

The oblong one is a varistor, the one that looks like a diode with a bit extra is a thyristor. Forgot to mention you will need the datasheet for these devices to do an appropriate test. cheers P&S

 

[Knobhead]

They're a sealed unit so I don't know what you hope to test.

 

[davesparks]

The flux capacitor?

 

[Knobhead]

The oblong one is a varistor, the one that looks like a diode with a bit extra is a thyristor. Forgot to mention you will need the datasheet for these devices to do an appropriate test. cheers P&S

Zener diode. A thyristor has three legs.

 

[plugsandsparks]

Zener diode. A thyristor has three legs.

Makes more sense Tony, realised they are switched devices but it is the symbol for one but looked like gate control was silent on the drawing. Was wondering why they would bother with one on there LOL

 

[wozz]

They're a sealed unit so I don't know what you hope to test.

I was told it was possible to test if it was functioning, as in to get typical continuity readings for one, but in my mind that was not possible.

 

[SheffSimon]

I was told it was possible to test if it was functioning, as in to get typical continuity readings for one, but in my mind that was not possible.

I've swapped a few failed ones, the only test I've ever done on them is measuring the DC output voltage, typically 180V if they are powered from 2 phases, about 120VDC if they are off phase and star point. If they're not working then bin em because they're a sealed unit.

 

[Knobhead]

If you have any number of SEW drives it worth a trip to their factory for training. There’s a lot more to setting up the brakes than you may think.

 

[ericks]

Makes more sense Tony, realised they are switched devices but it is the symbol for one but looked like gate control was silent on the drawing. Was wondering why they would bother with one on there LOL

You were correct, they are thyristors, they just don't want to show you the rest of the gate control circuit! (in case you want to copy their design). Zener diode symbols don't look like that...

*they might even actually use the thyristors as in the drawing with the gates left unconnected...