Leroy Somer's new HT range of motors, which is designed to maintain the
operation of vital ventilation systems in the event of fire, is capable
of surviving such conditions for a good deal longer than that laid down
in the new draft European standard for such motors, Pre-EN 12101-3.
During their development, HT motors were subjected to accelerated
high-temperature ageing tests; the result is that they exceed the
standard's recommended survival time by some 300%.
Two types of motor are available: the HTA aluminium framed version
(0.4-132kW), which can withstand temperatures in the 200-300oC region for
between one and two hours, and the HTC cast-iron framed version
(1.1-400kW), which can withstand up to 400oC for between one and two
hours. Importantly, the HTA will operate across both S1 ('comfort') and
S2 ('emergency') duties, while the HTC is currently designed for S2 duty.
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