These high efficiency explosion-proof
motors are UL® listed for dust ignition
proof environments, and are suitable for
use in Class I, Group D, Class II, Groups F
& G, Division 1 hazardous areas. They
are ideal for use in applications such as
chemical processing, mining, foundry,
pulp and paper, waste management,
and petro/chemical.

Performance Specifications

• 1 to 300 HP
• 1.0 service factor, 40ºC ambient
• T3B temperature code
• 900, 1200, 1800, or 3600 RPM
• 3 phase, 60 Hz; 230/460 volt
  operation under 25 HP, 460 volt 25
  HP and above; 200 & 575 volt
  available
• Class F insulation, Class B temperature rise
• NEMA design B, continuous duty
• 143T through 449T frame

Features for Long Life

Frame and End Shields – Cast iron
frame and end shields for exceptional
structural integrity, with sintered
condensation drains on 404T – 449T
frames. Lifting eyebolts are included for
frames 213T to 449T.

Rotor – A unique offset rotor bar design
provides improved efficiency while
larger bars and end rings reduce
resistance for lower rotor losses. Each
die cast aluminum rotor assembly is
dynamically balanced for extended
bearing life, and includes a highstrength
carbon steel (C1045) shaft for
maximum rotor performance.

Stator/Windings – Manufactured with
premium electrical grade steel
laminations and copper electrical
magnet wire to lower losses for
improved efficiencies. A unique stator
core design lowers flux density while
increasing cooling capacity. Large
conductor cross section reduces
resistance and lowers stator losses.

Insulation – Proprietary Class F nonhygroscopic insulation system with
NEMA Class B temperature rise, provides
an extra margin of thermal life. Varnish
system application ensures maximum
wire penetration to provide protection
from moisture, corrosion and electrical
shock. Two series- connected normallyclosed Class B thermostats are supplied as standard.

Cooling – A bi-directional, non-sparking
fan is locked and keyed to the shaft. Its
low-inertia design reduces windage
losses, improves airflow, reduces noise
and provides dependable cooling. Cast
iron fan covers are provided on all frame
sizes.

Bearings – Regreasable, oversized single
shielded bearings with cast iron inner
caps. Alemite grease fittings on the
inlets, and pipe plugs on the relief ports
for ease of routine maintenance. Frames
143T – 256T are equipped with a shaft
seal on the drive end; 284T – 449T
frames have a drive end V-ring slinger
for added bearing life.

Lubrication – A specially formulated,
high temperature tested, polyurea based
grease is used to provide more than four
times the lubrication life of other
polyurea greases.

Oversized Conduit Box – Cast iron
construction that is larger than industry
standards, diagonally-split and rotatable
in 90º increments for quick and easy
connections. Includes a ground lug and
non-wicking, clearly and permanently
marked leads.

Corrosion Resistance – Cast iron
construction, zinc-plated hardware,
epoxy enamel paint and stainless steel
nameplate resist rust and corrosion.

Modifiable – All Siemens motors are
available with a wide variety of
modifications to meet your specific
motor needs.