SCXI-1120D input voltage protection:

[feilong]

Hello All,

I have a SCXI-1120D input voltage protection question:
the data sheet specified 250Vrms. Does it mean signal plus CMV only? What if my signal itself is has a large potential difference (thus not CMV) , say 20V? Will the SCXI 1120D be damaged?

Thanks

Feilong

[Ima U]

Hi Feilong,

You are correct. The 250 Vrms refers to your signal plus the CMV. See Figure 3-2 on page 32 of the SCXI 1120D User Manual. The paragraph above Figure 3-2 also explains this. I hope this helps!

[feilong]

Thanks Ima for your reply. So according to my understanding, in case there's almost no CMV in my signals, then the 1120D could tolerate up to 250Vrms signal?

feilong

[Ima U]

Hello Feilong,

Channel to channel, or Channel to ground should not exceed 250 Vrms. If you have less CMV then you can have more Vs as long as they add up to less than 250Vrms. I hope this helps!

[feilong]

Thanks Ima, You get me fully assured.

[Ima U]

Hi Feilong,

You are very welcome! I wish you the best in your application.