Terminology - WEG W22 Premium E3 Manual De Instalación, Operación Y Mantenimiento

www.weg.net

1. TERMINOLOGY

Balancing: the procedure by which the mass distribution of a rotor is checked and, if necessary, adjusted to
ensure that the residual unbalance or the vibration of the journals and/or forces on the bearings at a frequency
corresponding to service speed are within specified limits in International Standards.
[ISO 1925:2001, definition 4.1]
Balance quality grade: indicates the peak velocity amplitude of vibration, given in mm/s, of a rotor running
free-in-space and it is the product of a specific unbalance and the angular velocity of the rotor at maximum
operating speed.
Hazardous area: area in which an explosive atmosphere is present, or may be expected to be present, in
quantities such as to require special precautions for the construction, installation and use of electrical
apparatus.
[IEC 60050 IEV number 426-03-01]
Non-hazardous area: area in which an explosive atmosphere is not expected to be present in quantities such
as to require special precautions for the construction, installation and use of electrical apparatus.
[IEC 60050 IEV number 426-03-02]
Explosive atmosphere: mixture with air, under atmospheric conditions, of flammable substances in the form
of gas, vapour, dust, fibres, or flyings which, after ignition, permits self-sustaining propagation.
[IEC 60050 IEV number 426-01-06]
Temperature class: maximum surface temperature of the equipment. Following temperature classes are
defined:
IEC
T1
T2
-
-
-
-
T3
-
-
-
T4
-
-
-
[IEC 60050 IEV number 426-01-05]
Simple apparatus: electrical component or combination of components of simple construction with well-
defined electrical parameters which is compatible with the intrinsic safety of the circuit in which it is used.
[IEC 60050 IEV number 426-11-09]
Flameproof enclosure "d" (Ex d): type of protection in which the parts capable of igniting an explosive gas
atmosphere are provided with an enclosure which can withstand the pressure developed during an internal
explosion of an explosive mixture, and which prevents the transmission of the explosion to the explosive gas
atmosphere surrounding the enclosure
68 Manual of Electric Motors
Temperature Class
NEC
T2A
T2B
T2C
T2D
T3A
T3B
T3C
T4A
Maximum surface temperature (°C)
T1
T2
T3
T4
T5
T6
450
300
280
260
230
215
200
180
165
160
135
120
100
85