What is the maximum allowable voltage drop for an audible device?5,10,15 or 20% What is the maximum distance 18 AWG wire is suitable for a self contained siren? What is used to reduce current?resistor or capacitor?
NFPA 70-2002 215.2(A)4 FPN 2 suggests limiting all branch circuits to no more than 3%. 5% overall when considering the feeder.
NFPA 70-2002 110,3(B) requires that listed and labeled equpment be installed in accordance with the manufacturer's documentation. In other words, the maximum voltage drop permitted is the difference between the power source and the device's minimum nameplate voltage.
How much current does the siren require? What's its minimum nameplate voltage? 1-strand 18AWG or 7-strand? Aluminum, copper (coated or uncoated), or copper-clad alumunum?
A resistor can be used to limit current.
Happy holidays,
Mike
-- Michael B. Baker, SET Michael Baker & Associates, Inc. PO Box 737 Gladstone, OR 97027-0737
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