MGM
Temperature, altitude, humidity
18
GENERAL CHARACTERISTICS
The standard electrical specifications of the motors are referred to continuous duty (S1), nominal voltage, nominal frequency (50 to
60 Hz), an ambient temperature of max 40
°
C and installation elevation up to 1000 m. above sea level.
If ambient temperature is higher than 40
°
C the permissible output power should be reduced by a percentage of the rated value
(see the table below).
Environment Temperature
°
C
Permissible Output Power as percentage of the Rated Power.
40
100
45
96.5
50
93
55
90
60
86.5
Elevation above the see level
Permissible Output Power as percentage of the Rated Power.
1000
100
1500
97
2000
94.5
2500
92
3000
89
3500
86.5
4000
83.5
If ambient temperature is higher than 60
°
C or lower than -30
°
C please contact the MGM technical office. If the motor is going to work
at an elevation higher than 1000 m. above sea level, the permissible output power should be reduced by percentage of the rated value
(see the table below).
Motors working in low temperature or high moisture environments
If a motor has to be used in an environment where the temperature is lower than -15
°
C, in high moisture or where abrupt temperature
changes can occur, it is advisable to use anti-condensation heaters. This recommendation is particularly important where there are long
pauses between working cycles, which may cause abundant condensation on the motor windings. It could permeate the windings and
cause short circuits. This occurs mostly on larger motors, which contain more air volume inside, allowing more humidity to condense.
Two anti-condensation heaters are fitted on the windings heads in order to increase the internal motor temperature so as to prevent
the air condensation.
Three different types of heaters are used according to the motor size. The wiring leads of the heaters are connected to the terminal board
located in the terminal box. The presence of anti-condensation heaters is shown by the writing “SCALD” followed by the required supply
voltage in the field 29 of the nameplate (according to nameplate paragraph). The heaters must not be supplied during the motor operation.
Additional protection against moisture may be provided by drain holes on the motor to allow water drainage. Drain holes option is provided
on request only and it is necessary to specify in the order the mounting to properly position the holes on the motor.
As standard MGM motors have the stator winding and brake coil treated to work in tropical environments. However a specific tropicalization
treatment can be requested, for all motors that have to be installed in high humidity environments.
A rain roof is available on request, for outdoor use or in presence of water jets with vertical mounting and shaft down. The rain roof is
positioned above the fan protecting the motor from water and permitting the regular flow of the cooling air. There is no need of a rain
roof on BA motors thanks to its particular construction and just a special brake cover for outdoor vertical mounting can be used.
Where brake motors are used in moisture environments or where there are long periods between working cycles, brake disc sticking
can occur. To avoid disc sticking it is possible to provide zinc plated or stainless steel brake friction surfaces according to the motor type.