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OC Motor Pool and Maintenance Shop <br />PDC Project 23017 Transfer Switches 26 36 00 - 4 <br />J.Service Conditions: Provide transfer switches suitable for continuous operation at indicated <br />ratings under the service conditions at the installed location. <br />K.Enclosures: <br />1.Environment Type per NEMA 250:Unless otherwise indicated,as specified for the following <br />installation locations: <br />a.Indoor Clean,Dry Locations: Type 1 or Type 12. <br />b.Outdoor Locations: Type 3R or Type 4. <br />2.Provide lockable door(s)for outdoor locations. <br />3.Finish: Manufacturer's standard unless otherwise indicated. <br />L.Short Circuit Current Rating: <br />1.Withstand and Closing Rating: Provide transfer switches,when protected by the supply side <br />overcurrent protective devices to be installed,with listed withstand and closing rating not less <br />than the available fault current at the installed location as indicated on the drawings. <br />M.Automatic Transfer Switches: <br />1.Description: Transfer switches with automatically initiated transfer between sources; <br />electrically operated and mechanically held. <br />2.Control Functions: <br />a.Automatic mode. <br />b.Test Mode: Simulates failure of primary/normal source. <br />c.Voltage and Frequency Sensing: <br />1)Undervoltage sensing for each phase of primary/normal source;adjustable <br />dropout/pickup settings. <br />2)Undervoltage sensing for alternate/emergency source;adjustable dropout/pickup <br />settings. <br />3)Underfrequency sensing for alternate/emergency source;adjustable dropout/pickup <br />settings. <br />d.Outputs: <br />1)Contacts for engine start/shutdown (except where direct generator communication <br />interface is provided). <br />2)Auxiliary contacts;one set(s)for each switch position. <br />e.Adjustable Time Delays: <br />1)Engine generator start time delay;delays engine start signal to override momentary <br />primary/normal source failures. <br />2)Transfer to alternate/emergency source time delay. <br />3)Retransfer to primary/normal source time delay. <br />4)Engine generator cooldown time delay;delays engine shutdown following retransfer <br />to primary/normal source to permit generator to run unloaded for cooldown period. <br />f.In-Phase Monitor (Open Transition Transfer Switches): Monitors phase angle difference <br />between sources for initiating in-phase transfer. <br />g.Engine Exerciser: Provides programmable scheduled exercising of engine generator <br />selectable with or without transfer to load;provides memory retention during power <br />outage. <br />3.Status Indications: <br />a.Connected to alternate/emergency source. <br />b.Connected to primary/normal source. <br />c.Alternate/emergency source available. <br />d.Primary/normal source available. <br />4.Other Features: <br />a.Event log. <br />b.Remote monitoring capability​​​​. <br />5.Automatic Sequence of Operations: <br />a.Upon failure of primary/normal source for a programmable time period (engine generator <br />start time delay),initiate starting of engine generator where applicable. <br />Docusign Envelope ID: EF9C08D2-5B75-438B-8D6D-8473F81BD7C4