EAS911 Unit, trying to understand relay closures

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abwdvm
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EAS911 Unit, trying to understand relay closures

Post by abwdvm » Tue Oct 17, 2017 2:04 pm

I have been tasked with revamping the EAS relays.

We have an EAS911 unit.

I cant figure out why there are 2 wires, one carrying 36vdc from the transformer, and one that is grounded.
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20171017_145314.jpg
relay bank shown below, EAS wires shown
technician at an 1000w AM station in Texas

awsherrill
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Joined: Fri Nov 16, 2007 10:30 pm
Location: Raleigh NC

Re: EAS911 Unit, trying to understand relay closures

Post by awsherrill » Tue Oct 17, 2017 4:02 pm

The other end of that cable should be going to either a TFT EAS-940 relay box, or else a homebrew relay apparatus, to insert EAS audio into an air chain.

The DC voltage on one of your wires is probably coming from the relay coil(s) in the TFT relay box. The relay inside the EAS911 will route it to ground to pull in the air chain relays while sending an alert.

Darryl Parker's contact information is at the top of this forum section if you need it.

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