Cut Sheet

55
Technical Data TD01701001E
Effective March 2017
UL low-voltage busway
Pow-R-Way III
EATON www.eaton.com
2.04 Conductor bus bars
A. Bus bars shall be fabricated from high strength, 57% conductivity
aluminum or 99% conductivity copper and shall be suitably silver-
(or) tin-plated at all electrical contact surfaces.
B. Bus bars shall be insulated over their entire length, except at
joint and contact surfaces, with Class B, 130 °C, epoxy insulation
applied by the fluidized bed process. The epoxy insulation shall
extend fully to the joint contact surface.
C. The busway shall be capable of carrying rated current
continuously without exceeding a temperature rise of 55 °C
based on a 40 °C ambient.
2.05 Bus joints
A. Each busway section shall be furnished complete with joint
hardware and covers. The busway joints shall be a single-bolt,
non-rotating, removable bridge design. All bridge joints shall be
furnished with [standard torque-indicating double head joint bolts
and Belleville washers. The bridge joint shall utilize a captive nut
retainer on the opposite side of the torque-indicating bolt. The
bridge joint design shall ensure proper installation without the
use of a torque wrench, and provide visual indication that
the joint has been tightened to the proper torque value]. —OR—
[an optional tension indicating SmartBolt and Belleville washer.
The bridge joint shall utilize a captive nut retainer on the opposite
side of the tension-indicating bolt. The bridge joint design shall
ensure proper installation without the use of a torque wrench,
and provide visual indication through a color changing window
on the bolt head that the joint has been tightened to the proper
internal tension value.] Each indoor busway joint shall allow
for a minimum length adjustment of ±0.5 inches (12.7 mm).
De-energization of busway shall not be required for safe
testing of joint tightness. The bridge joint shall be the
Eaton Pow-R-Bridge.
2.06 Housing
A. The busway housing shall be an all-aluminum construction.
The housing shall be manufactured as a two-piece design only,
and shall be fabricated from extruded aluminum. The two-piece
housing shall be bolted along the bottom flange only, using
Grade 5, 1/4 x 20 zinc-plated hardware on 3.00 inch (76.2 mm)
centers for maximum mechanical strength. The busway enclosure
finish shall be ANSI 61 gray baked epoxy powder paint applied by
an electrostatic process.
B. Outdoor feeder busway housing shall be identical to indoor
feeder busway housings, and shall be UL listed for outdoor use.
Busway shall be completely weatherized at the factory, and
designed with a two-piece metal joint cover so that no caulking
is required by the installer to achieve an IP66 rating suitable for
outdoor use.
C. The busway shall have a minimum short-circuit withstand rating
of 85 kA rms symmetrical for ampere ratings through 800 A,
100 kA rms symmetrical through 1350 A, 125 kA rms
symmetrical through 1600 A, 150 kA rms symmetrical through
2500 A, and 200 kA rms symmetrical for ratings through 5000 A.
2.07 Plug-in busway
A. Where required, busway shall be of the plug-in type. Plug-in
busway shall be available in standard 24.00 inch (609.6 mm)
incremental lengths not to exceed a maximum length of
10 ft (3 m). Plug-in outlets shall be provided on both sides of the
busway on 24.00 inch (609.6 mm) centerlines. The design shall
allow for 10 cover outlets per 10 ft (3 m) section. Covers for plug-
in openings shall have a positive screw close feature and shall
require the use of a tool to open. Plug-in outlet covers shall
prohibit dirt and debris from entering the plug-in contact openings
in the busway and shall have provisions for the installation of
power company seals.
B. The plug-in contact surfaces of the bus bars shall be constructed
of conductor tabs, welded to the side edges of the bars. The
tabs shall be of the same (full) thickness, rating, and material as
the bus bars. The contact surfaces shall receive the same plating
process as the joint contact surfaces.
C. Plug-in and feeder busway of the same ampere rating shall have
identical short-circuit withstand ratings.
D. Positive mechanical guides for plug-in units shall be provided
at each plug-in outlet to facilitate unit alignment and to prevent
improper installation.
E. The plug-in busway shall maintain the same sandwich bus design
as the feeder busway. Plug-in busway with bus bars that are
separated or flared at the plug-in opening shall be unacceptable.
F. Plug-in outlets shall be furnished with barriers across the
plug-in openings to prevent accidental contact with a live
part by an operator or installer.
G. Where required, indoor sprinkler-proof plug-in busway shall be
provided with housing identical to the standard plug-in bus.
Sprinkler-proof busway shall carry an ingress protection rating
of IP55 with the plug-in openings closed.
H. Where required, plug-in units of the types and ratings indicated
on the contract drawings shall be supplied. Plug-in units shall be
mechanically interlocked with the busway housing to prevent their
installation or removal while the switch is in the ON position. The
ground stab of any plug-in unit shall make a positive connection
with a busway ground (housing or internal) contact, inside the
plug-in outlet, before the phase and neutral stabs make contact
with the contact surfaces of the bus bars. All plug-in units shall
be equipped with a defeatable interlock to prevent the cover
from being opened while the switch is in the ON position and
to prevent the accidental closing of the switch while the cover
is open. The operating mechanism and handle shall remain in
control of the disconnect device at all times, permitting easy
operation from the floor by means of a hookstick or chain. For
safety reasons, no projections shall extend into the busway
housing other than the plug-in stabs. All plug-in units shall be
interchangeable without alteration or modification to the busway.
I. Fusible-type bus-plugs shall have a quick-make, quick-break
disconnect switch and positive pressure fuse clips.
J. Circuit breaker type bus plugs shall have an interrupting rating
as indicated on the contract drawings and shall meet all the
requirements of UL Standard 489. It shall be possible to increase
the interrupting rating of a breaker plug-in device having ampere
ratings through 400 A up to 100 kAIC at 480 Vac and 200 kAIC at
240 Vac by changing out the circuit breaker only and leaving the
enclosure intact. All circuit breaker plug-in devices shall be Eaton
type Series C.
K. Current limiting circuit breaker type plug-in devices shall be
units that provide integral time delay/thermal trip protection and
current-limiting protection in one assembly. These breakers shall
be UL rated at 200 kAIC at 240 Vac and 150 kAIC at 480 Vac,
and shall be series-rated to protect all molded-case breakers
downstream as shown on the contract drawings.
L. Where indicated on the contract drawings, provide bus plugs with
Surge Protective Device (SPD). SPD units shall incorporate Metal
Oxide Varistors (MOVs) for suppression of AC transients and
filtering capacitors to eliminate electrical line noise and ringing
transients. Ratings of SPD bus plugs shall be as indicated
on the contract drawings. SPD units shall be Eaton’s Clipper
Power System.
M. Where indicated on the contract drawings, provide circuit breaker
bus plugs with programmable microprocessor-based trip units
that have coordination, communication, monitoring, and advanced
warning capabilities. Programmable breaker bus plugs shall be
Eaton’s Digitrip OPTIM.