Howard Network Transformers - Manual (Page 6)

Optional Features and Accessories
The following optional features and accessories are avail-
able. Check with the factory for the availability of other
features and accessories not listed.
• Series-multiple high-voltage winding
• Delta-wye connection
• Special high-voltage taps
• Special low-loss high efficiency designs
• Design optimization to lowest total owning cost
• 50 Hertz operating frequency
• Special impedance
• Special sound level
• Special phase relationship
• Special BIL level
• Over excitation capability
• 65° C average temperature rise
• Special ambient temperature
• Operation at altitudes above 3300 feet
• Copper windings
• Core ground test point located inside tank accessible
from bolted handhole
• Electrostatic shields
• Optional tank features and accessories
− Special hardware
− Welded handhole cover
− Additional bolted or welded hand-hole
− Special tank design pressure (up to 15 psig)
− Ground connectors
− Special tank dimensions
− Tank undercoating
− Omit pressure-relief valve
• Optional gauges and fittings
− Dial-type magnetic liquid-level gauge (with alarm
contacts)
− Dial-type thermometer (with alarm contacts)
− Pressure-vacuum gauge (with or without alarm
contacts)
− Automatic pressure-relief device (with or without
alarm contacts)
− Drain valve with liquid sampling valve
− Additional drain valve on tank or switch chamber
− Spare gaskets for secondary throat, bolted hand-
holes, high-voltage terminal chamber, and switch
chamber
− Sight gauge for high-voltage terminal chamber
− Other options (check with factory)
• Optional high-voltage switch features and accessories
− Interrupting switch or other special switches
− Provisions for phase sequence identification
(phasing tubes)
− Phase sequence indication (sequential ground-
ing), including 3 internal grounding contacts,
5-position switch to indicate phase when switch is
moved from transformer positions to ground posi-
tion
− Additional electrical interlocks
− Viewing windows for observation of switch blades
(with hinged protective cover)
• Optional high-voltage entrance features and accessories
− Single-conductor or multi-conductor wiping
sleeves, or pothead entrance
− Six universal bushing wells for loop feed with or
without loadbreak inserts (HV switch must be
omitted)
− Three integral loadbreak bushings
− Three non-Ioadbreak bushings
− Six non-Ioadbreak bushings for loop feed (HV
switch must be omitted)
− Six integral loadbreak bushings for loop feed (HV
switch must be omitted)
− Three molded bushings mounted on front of
terminal chamber in lieu of the standard wiping
sleeve
− Potheads, one 3-conductor or three 1-conductor,
instead of the standard terminal chamber
− Bottom entrance of HV cable, including wiping
sleeves
− Packing gland or stuffing box
− Phase separation barriers in compartment (when
switch is omitted)
− Dielectric fluid or compound for terminal chamber
• Optional low-voltage air terminations
− Welded low-voltage bushings
− Fully insulated low-voltage neutral bushing
− Other low-voltage termination options (check with
factory)
• Optional network protector provisions (check with factory)
• Optional dielectric fluids
− Silicone fluid
− FR3 natural ester-based fluid
Network Transformer
94-10
Copyright © 2010 Howard Industries, Inc.
6
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
Catalog Section 94-10
Network Transformers
Issued: April 9, 2010