Federal Signal Corporation 2-240, Инструкция по установке, эксплуатации и обслуживанию

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SECTION IV
CIRCUIT DESCRIPTION
4-1. SIREN CONTROL DESCRIPTION
The Model RC2W is used to operate a Model 2 Siren.
The RC2W is a motor starter that switches the power to the Model 2 siren. The RC2W requires a siren
controller to provide Steady and Wail type siren signals typically used for warning applications. The
siren controller will hold a contact closed to activate the RC2W for a Steady signal and will cycle the
contact open and closed to create a Wail signal. The RC2W also provides overload protection for the
siren motor.
As shown in figure 3-4, the motor starter includes an overload relay. The relay protects the motor
starter and the motor in the event that excess current is drawn. The overload relay is activated when
there is sufficient
current through one or more of its heaters to cause the heater(s) to expand enough to open the
relay contacts. The opening of the relay contacts opens the motor starter control circuit. As a result the motor
starter de-energizes, protecting the circuit against damage. After the motor starter de-energizes, the relay contacts
reset automatically
when the heater(s) cools sufficiently. The overload relay can also be reset manually after
approximately one minute.