STAR PERFORMERS IN FLOAT
GLASS PRODUCTION
TYPE W -- THREE PHASE STARBARS
Star performers in float glass
production, Type W three-phase
®
Starbars are comprised of high
purity, high density, silicon carbide
grains, self bonded through
recrystallization at elevated
temperatures. Sintering at
temperatures in excess of 2200ºC
provides a structural density of
2.50 grams per cubic centimeter.
Such high structural density
®
results in Starbars of maximum
strength and minimum porosity,
with an extremely slow aging
characteristic.
®
Strength of the Starbars is
further enhanced by insertion of
hot zones into oversized cold
ends. Enlarged cold ends
measure 28mm(1.10”) in
diameter, accommodating hot
zones of 19mm (0.75”) in
diameter.
Close tolerance sizing helps
®
assure Starbar fit to conventional
roof construction. Leg to leg oncenter spacing is 52mm(2.05”).
Overall element length is 647mm
(25.47”). Length of hot zone is 265mm (10.43”). Height of bridge is
32mm (1.26”). Cold end length is 350mm (13.78”). The support
hole is 5.6mm (0.22”) in diameter and 44mm (1.73”) from the top of
the cold end.
ELECTRICAL CONNECTIONS
Electrical connections are
(3) SILLIMANITE STEP
SUPPORT WASHERS
made at the three
aluminum sprayed ends,
with cold ends kept cold
2.12
2.52
[54]
[64]
through oversizing, and
use of a special, low
(3) 75 AMP ALUMINUM CONNECTOR
STRAP ASSEMBLY
resistance end material.
0.39 [10] HOLE DIAMETER
Cold end hardware for
each element includes:
0.94 [24]
(3) 75 amp, bolt-type,
aluminum strap
connectors, (2) stainless
steel support pins (cotter
pins) and (3) sillimanite step washers.
1.97 [50] OUTER DIAMETER
1.54 [39] STEP DIAMETER
1.18 [30] INNER DIAMETER
2.00
[51MM]
0.12 [3]
1.57 [40]
ALUMINUM
SPRAY
0.25
[6.3]
Washers available for support and sealing include flat ceramic
washers, ceramic step washers, stainless steel flat washers, and
compliant fiber washers.
08/26/99
(2) STAINLESS STEEL
SUPPORT PINS
FLOAT.DOC
0.79
[20]
MANUFACTURED TO WORKING SPECIFICATIONS
To meet stringent float glass performance requirements, all
®
Type W three-phase Starbars are calibrated at least twice
at 69 volts, at a surface temperature of 1070ºC. With a
nominal resistance of 0.85 ohms (+/- 20% manufacturing
tolerance), individual shipments are matched, within tight
tolerances, to your stated specifications. Calibrated
®
amperage is clearly marked on the Starbars , on individual
®
Starbar cartons, and on the 920mm (36”), cubed, wooden
crates, containing 50 carefully packed elements. Hot zone to
cold end resistance ratio is guaranteed minimum 17 to 1,
®
with Starbars designed to operate comfortably at a loading
of 3.75 kW.
CONSTRUCTED FOR LONG LIFE
! COOLER OPERATING COLD ENDS: The cold ends of
®
Type W three-phase Starbars are 9mm (0.35”) larger in
diameter than the hot zones, and are comprised of a special
low resistance end material. Featuring a negative
resistance/temperature curve, as the cold ends are exposed
to heat, resistance to current passage lessens, resulting in
significantly cooler operation.
! SLOWER AGING HOT ZONES: With a structural density
®
of 2.5 gram/cc, Type W three-phase Starbars feature the
extremely slow aging characteristic most desired in float
glass production. High density helps prevent the hot zone’s
internal lattice structure from being oxidized, while
®
considerably enhancing the Starbar’s strength.
! UNIQUE SPLIT BRIDGE CONSTRUCTION: Over a
considerable period of time, our field and laboratory testing
has identified the bridge as the weakest point of design in
the three phase element’s structure. To enhance bridge
strength, we have employed a unique split bridge
®
construction. Our Starbar bridge is manufactured in two
distinct halves, split longitudinally across the element’s width.
When the element is assembled, the ends of element hot
sections (together with both halves of the split bridge) are held
together with epoxy. Then the bridge is fired in a silicon
atmosphere. This converts the free carbon in the epoxy to
silicon carbide, essentially making a silicon carbide weld. The
bridge is very strong, low in resistance, and high in density.
PACKAGED FOR FLAWLESS PERFORMANCE
®
All Type W three-phase Starbars are wrapped in soft foam
rubber and individually placed inside corrugated cardboard
containers. Fifty element cartons are then packed, bridges
down, into a wooden shipping container, with additional soft
packing added, prior to direct shipment to your float glass
facility. The part number is
WDB 647x265x350x19/28 or WDB 25.5x10.4x13.7x0.7/1.1.
I Squared R Element Co., Inc. 12600 Clarence Ctr. Rd., Akron NY 14001 Phone: (716) 542-5511
FAX: (716) 542-2100 email:[email protected] web: WWW.ISQUAREDRELEMENT.COM
08/26/99
FLOAT.DOC