Firelite MS-5UD Relays

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Tue Jun 11, 2019 5:24 pm


I have a Firelite MS-5UD that is being used for enthusiast purposes. I was wondering what the maximum voltage the relays can support before, well, blowing out. Reason is that I wanted to unorthodoxly wire a 120V~ Exit Sign to an alarm relay (Positive being untouched), and remove the battery to the exit sign; so that in an alarm the sign would activate. Definitely not up to NFPA code, but for me it would work.


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Tue Jun 11, 2019 8:10 pm

According to the drawing in the MS-5 installation manual the relays are rated for 30 volts maximum. My suggestion is to isolate the 120 VAC circuit using a relay like a PAM-1, -2, or -3. Switch 24 VDC from the panel output through a panel relay to operate the PAM relay.

PAM relays are available from a number of sources. ... -52068.pdf
MS-5UD_relays.png (22.59 KiB) Viewed 89 times
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