The food and beverage industry has always had
problems with motors that are hosed down for cleanliness and
hygiene reasons in processing plants. The high pressure cleaning
with extreme caustic solutions has in the past contributed to
the failure of many motors on the production line, which has
always been a concern. Both aluminium and cast iron motors fail
to stand up to the caustic solutions which eat away the motor
material at a rapid rate, while the effects of hosing and condensation
create havoc with the motor. If motors are covered with paint
or an epoxy coating the coating can easily chip and create havoc
with the motor.
Harrington Electric Motors has developed a complete range
of rolled stainless steel, IEC metric frame motors, which
are completely interchangeable with all other electric motor
in industry. The motors start at 0.18 kW and go through to
7.5 kW in all speeds. Whether the electric motor is foot,
flange, foot and flange mount or 'C' face mount the Scorpion
motor can replace any existing motor.
Even though the motors are stainless steel and it is difficult
to get the heat out of the motor, the windings are of such
a quality and so efficient they can be supplied totally enclosed,
no ventilation (TENV) in smaller sizes up to 0.75 kW. Without
a cooling fan or fan cowl the motors still run cooler than
standard electric motors. As SEW-Eurodrive has a huge share
of the food industry market, the Scorpion motor can be supplied
with SEW dimensions, which allows them to be fitted straight
onto any SEW gearbox with no adaptation to flange or shaft
required.
The absence of cooling fins on the motor allows for ease of
cleaning as food particles cannot be caught between the fins
of the motor. The rolled steel body is made from 304 grade
stainless along with the shaft while the endshields are 302
stainless. Any harsh caustic solutions have no effect on the
motor while the addition of an etched nameplate in the stator
housing means nameplates can never be lost or illegible. A
weakness with electric motors in harsh environments is condensation
inside the motor caused by the change of temperature between
the inside and outside of the motor.
To ease this problem the Scorpion motor has been fitted with
four quadrant drain plugs on each endshield, so that no matter
how the motor is mounted there will always be a drain plug
at the lowest point of the motor. The motor is fitted with
a special 'T' drain at the lowest point, which stops water
from high pressure hosing entering the windings, but allows
condensation to drain out over a period of time.
The Scorpion's IP66 rating means it is completely hoseproof
from a strong jet of water from any angle. Double lip oil
seals in both endshields stop water entering along the motor
shaft. A Gamma Seal, which acts as a slinger to keep water
away from the oil seal, is fitted on the drive end shaft.
The stator windings are double varnished with a vacuum impregnation
system encapsulating the windings in varnish for protection
against water. The terminal box is insulated from the winding
housing by the use of a 12 mm rubber gasket. The winding leads
are completely encapsulated in the terminal box, which makes
the whole motor as close to fully submersible as possible.
The bearings are double rubber sealed, but low friction sealing
keeping the high efficiency status of the motor, C3 clearance
to allow for expansion and rating from -20 to + 200°C.
The Scorpion stainless motor is a complete solution and a
huge breakthrough in the war against bacteria in the food
and beverage industry.
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