Siemens S7, Digital Out 110/230v Bleeding voltage 322-1FH00-0AA0

This is a new install, two new cards, both are 6ES7 322-1FH00-0AA0

Heres the deal, All DO's switched off:

I get voltage bleed anywhere from 1.5v to 112v on various channels. Not all of them are doing this seems mostly on the lights, relays and coils (asco vavle coil) on the lights (warning illum's) I get 30v's, on the relays coil side I'm seeing up to 100v, on the asco control solenoids I'm seeing up to 112v

This is with not selected outputs on!

The lower votage is burning up all the coils in rested state, not enough voltage/current present to open the coils so the just heat up and burn the fields open.

Not sure what the causes of this are, any ideas or suggections would be hugley apprechiated!!!

I know that if you measure on thyristor outputs, you will measure a voltage even in the off state. But it is new to me that enough current can flow to heat up a coil until it melts.
Have you tried to measure the current ?

Sounds like a common problem. Triac leakage current into low wattage loads causes outputs to show voltage when off. The spec sheet I pulled up indicated 2ma of leakage in off state. However that should not be burning up coils. I'm thinking you should check that the neutral isn't floating.

Thank you both for the replies. Re-worked the neutrals on the card and at the chiller where we were having the issue with the relay coil; all is better now. Get .5 ma or less on all channels in off position.

This plc is replacing a old ab that used a relay card as outputs we switch to DO with the siemens. Seems the ab/relay output didnt mind the not so perfect common up to the chiller.



Thanks again!