[?]: 24vac PLC inputs ?

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Jbeard
Posts: 22
Joined: Fri Jun 28, 2019 1:08 am

[?]: 24vac PLC inputs ?

Post by Jbeard » Mon Jun 22, 2020 12:54 pm

I know that most PLC inputs are 24vdc,
but what would happen to the PLC if you applied 24vac to the inputs if it was a dc input?
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misa1515
Posts: 53
Joined: Mon Jan 03, 2011 10:51 am

Re: PLC inputs

Post by misa1515 » Mon Jun 22, 2020 3:35 pm

Hello,
24VAC on 24VDC input - value in PLC will flicker on 0 and 1
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Jbeard
Posts: 22
Joined: Fri Jun 28, 2019 1:08 am

Re: PLC inputs

Post by Jbeard » Mon Jun 22, 2020 7:17 pm

So that could be why we have alot of problems with these air handlers that are wired this way. The manufacturer says we don't know what where talking about.
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CoMod
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Re: [?]: 24vac PLC inputs ?

Post by CoMod » Thu Jun 25, 2020 1:39 pm

1. SIMATIC ET 200SP, digital input module, DI 8x 24 V AC...48 V UC
https://support.industry.siemens.com/cs ... 6cf00-0au0
6ES7131-6CF00-0AU0
ET 200SP, DI 8x 24VAC..48VUC BA, PU 1
(sdoc) https://support.industry.siemens.com/cs ... /109759596

2. use buffer relay, 24vac LZX:PT570524
https://support.industry.siemens.com/cs ... 3Apt570524
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