NORD Drivesystems B1091 - Manual (Page 12)

-12- B1091-GB-4613 www.nord.com
6. Motors for use in
Zone 21 and Zone 22
If the motor is supplied with a certified cable gland, the clamping nuts of the cable gland must be tightened to
the torque specified in the following table.
Cable
gland
Clamping nut
tightening torque [Nm]
M20x1.5 6
M25x1.5 8
M32x1.5 12
M40x1.5 16
The permissible ambient temperature range for all motors is -20°C...+40°C. An extended ambient
temperature range of -20°C...+60°C is permissible with motors for operation in Zones 21 and 22. However,
this does not apply with the option brake and external fan! The rated power must be reduced to 72% of the
catalogue value. If the maximum value of the ambient temperature is between +40°C and +60°C, the value
of the power consumption can be inversely interpolated linearly between 100% and 72%. In this case
thermal protection of the motor by means of a thermistor sensor is mandatory. The motor connection cables
and the cable glands must be suitable for temperatures
 90°C.
IEC-B14 Motors
The B14 flanged bearing cover must be covered with a protective foil which must be removed before the
motor is fastened in place. Even if they are not required, all four fixing screws must be screwed into the
flanged bearing cover! The fixing screw threads must be inserted with a sealant, e.g. Loctite 242.
The maximum depth for screwing into the bearing cover is 2 x d.
If the shaft end faces upwards, e.g. versions IMV3, IMV6, a cover must be positioned on the motor by the
operator/installer to prevent foreign bodies from falling into the motor fan cover (see DIN EN 50 280-1-1).
This must not obstruct the fan from cooling the motor. If the shaft ends face down, e.g. versions IMV1, IMV5,
motors for Zone 21 are generally equipped with a protective shield on the fan cover. A handwheel at the
second shaft end is not permitted.
Unless other operating modes and tolerances are specified in the test certificate or type plate, electrical
machinery is designed for continuous operation and normal infrequent start-ups where no significant start-up
heating occurs. The motors may only be used for the operating mode specified on the type plate.
The installation instructions must be strictly observed.
6.4 Structure and method of use
The motors are self-cooling. Rotary shaft seals are fitted both on the drive side (DS) and on the ventilation
side (VS). Motors for Zone 21 and Zone 22 have metal fans. The motors are produced with protection class
IP55, optionally protection class IP 66, (Zone 22 – non-conducting dust) or IP66 (Zone 21). Under normal
operating conditions, the surface temperature does not exceed the surface temperature stated on the type
plate.
6.5 Minimum cross section of bonding conductors
Cross-section of the phase conductor in
installation S in mm
2
Minimum cross-section of the associated
earth lead S
P
in mm
2
S ≤ 16
16 < S ≤ 35
S > 35
S
16
0.5 S
When connecting a lead to the external earth, the minimum cross-section must be 4 mm
2
.