Specifications - State of Delaware

SECTION 263600 - TRANSFER SWITCHES: continued
electrical load, and equipment components. Differentiate between portions of wiring that
are manufacturer factory-installed and portions that are field-installed.
4. Operation and Maintenance Manuals: Submit operation and maintenance manuals
complete with schematics and wiring diagrams.
5. All field test data.
PART 2 - PRODUCTS
2.01 THREE-PHASE TRANSFER SWITCHES:
A. General: Except as otherwise indicated, provide manufacturer's standard design, materials, and
components as indicated by published product information, designed and constructed as
recommended by manufacturer for duty indicated and as required for a complete installation.
Provide terminals UL-rated for 75ºC (minimum) conductors. Provide transfer switch designed
to resist forces of a Seismic Zone 2A event without damage.
B. Automatic Transfer Switches:
1. Provide factory-fabricated automatic transfer switches and auxiliary equipment of types,
sizes, ratings, and electrical characteristics for services indicated, which are electrically
operated, mechanically held, and electrically and mechanically interlocked. Provide
switch that monitors all three phase voltages. Provide Hand-Test-Automatic Selector
Switch:
a. Hand position: manual emergency generator starting with load transfer.
b. Test position: manual emergency generator starting with no load transfer.
c. Automatic position: automatic emergency generator starting and load transfer
during power failure.
2. Provide switches capable of automatically transferring the load from normal to
emergency source when normal line voltage drops below 70% of rated value and
transfers load back to normal source when voltage is restored to greater than 90% of rated
value. Provide switch with operating time of transfer to emergency in 10 seconds
including engine-generator starting and transfer emergency to normal in 1/6 second after
retransfer time delay. Equip switch with time delays to:
a. Prevent excessive transfer (adjustable 0-30 seconds) during momentary line voltage
dips.
b. Load retransfer (adjustable 0-15 minutes).
c. Engine cool down after retransfer and before shutdown (adjustable 0-20 minutes).
3. Provide spare NO switch contact which shall close when the load is on the emergency
source.
4. Provide switch with appropriate 10A, 32Vdc engine-starting contacts for starting
emergency engine-generator unit.
5. For inductive loads, equip poles with magnetic blowouts and arc barriers; for
noninductive loads, equip switches with arc barriers between poles.
6. Equip unit with test switch for manual simulation of power outages including emergency
generator unit operation and load transfer.
7. Provide one white (normal power) and one yellow (emergency power) indicating lamp.
8. Provide two spare 10A, 480Vac, SPDT auxiliary contacts.
9. Provide free-standing or wall mounted 14-gage welded steel NEMA Type 1 enclosure for
indoor, dry, non-hazardous locations with swing out service panel and door locks. Coat
enclosure with manufacturer's standard color acrylic enamel finish over a corrosionresisting
primer.
10. Provide all locks keyed identically, furnish five keys per lock.
263600-2 DEAN263600.DOC