Question about solid state relay

[Ogu Reginald]

Hi,
I have a solid state relay which can handle up to 70A but in the data sheet the input control voltage is between 4-32Vdc.
I know that if the control Voltage is below 4V, it wouldn't come ON but am not cleared on what will happen to the SSR if the voltage is above 32V.
I don't want to experiment because it is costly.

Please help me and tell me what will happen at about 40V control voltage.

 

[esp1]

hi,
Its possible that you will damage the Control input devices.
I use either 5V TTL or 12V logic

If you only have 40V control signals available, use a resistive divider , drop from 40V to around 6V
E

 

[KlausST]

Hi,

maybe a silly question:
Why did you choose the relay spec´d at max 32V and ask for 40V control voltage?
I´d either choose a higher rated SSR or choose a lower driving voltage.

The question to your answer "what will happen.." you can find in the datasheet, usually in the section about "absolute maximum ratings".

You say "below 4V, it wouldn´t come on.."
this is only half the truth.
In the datasheet you may find a voltage (maybe 1.5V) where the SSR is surely OFF, and above 4V it is surely ON.
But between this 1.5V and 4V ia an unalowed region. Don´t apply this voltage.


Klaus

 

[Ogu Reginald]

Thank you for your answers.

 

[betwixt]

That voltage range suggests to me that the input is an opto-coupler, it usually is on SSR devices. They are actually current driven and the specified voltages will provide the minumum to maximum currents allowed in the optocoupler LED. You can simply add a resistance in series with the control voltage to reduce the current to a safe level.

Brian.