12
Maintenance and service guide - LSN-FLSN ZONE
2 - Ex ec
5724 en - 2020.02 / c
7 - SPECIAL OPERATING
CONDITIONS
- Thermal protection (see § 6 & 9)
- Heaters (see § 6)
- Temperatures: storage and ambient
Note: T
a
= ambient temperatures
If the motor has been stored at a temperature below - 10°C,
heat the motor (see § 3) and turn the shaft by hand before
operating the machine.
If the motor is to be used at a temperature lower than - 20°C, it
may be fitted with heaters.
As standard construction, our motors are designed to operate
at ambient temperatures T
a
between - 20°C and 40°C.
If T
a
< - 25°C, shaft passage seals must be made of silicone and
the fan must be metal. The terminal box gaskets must be made
of silicone.
- Surface temperature
As standard, the maximum surface temperature at any point of
the motor is 200°C as T3 with an ambient temperature
≤
40°C.
If the motors are also used in dusty explosive surroundings, the
maximum surface temperature is 125°C.
- Installation zones
Motors bearing equipment group III marking may be installed
in dusty explosive atmospheres (zone 22).
- Connection
Particular attention must be paid to the information on the
nameplate in order to choose the correct type of connection to
the supply voltage.
Similarly the protection system and the supply cables (the
voltage drop during the starting phase must be less than 3%)
are to be selected according to the characteristics marked on
the nameplate.
- Earthing
The motor must be earthed in accordance with the applicable
regulations (protection of workers).
An external terminal on the frame is used for effective earth
connection of equipotential links. This terminal must be
prevented from working itself loose.
- Leak tightness
Monitor the condition of all seals and periodically replace them
if necessary. At the shaft passages, take care not to damage
the seals in contact with the keys and shoulders.
After removing drain plugs or ventilators where these are
present, refit them in place in order to ensure the IP 55 or IP 65
degree of protection of the motor. Replace the seals that are
removed using new seals with the same characteristics. Clean
the orifices and plugs before refitting them.
Whenever removed and during preventative maintenance,
replace seals (shaft passages, bearing housing recesses,
terminal box cover etc.) using new seals with the same
characteristics after cleaning the components. Shaft passage
seals must be fitted using the same type of grease as the
bearings.
- Employee safety
Protect all rotating devices before power-up.
If a motor is started up without a coupling device having been
fitted, carefully immobilize the key in its housing.
All measures must be taken to provide protection against risks
associated with rotation of components (sleeve, pulley, belts etc.).
Beware of backdriving when the motor is switched off.
Appropriate precautions must be taken:
- pumps, install a non-return valve, for example.
- NIDEC LEROY-SOMER “Digistart” electronic starter
This is micro-controlled multi-function electronic system,
which is used with all squirrel-cage asynchronous three-phase
motors.
It ensures smooth starting of the motor with:
- reduced starting current,
- smooth jerk-free acceleration achieved by controlling the
current in the motor.
After starting, the DIGISTART carries out additional motor
management functions in its other operating phases: steady
state and slowing.
- Models from 18 to 1600 A
- Power supply: 220 to 700 V - 50/60 Hz
The DIGISTART is low-cost to install, and only an additional
switch and fuses are required.
The “Digistart” electronic starter associated with the
motor must be installed outside the hazardous zone.
- Contactors - Main switches
In all cases contactors, main switches etc. must be
installed and connected in a panel outside the hazardous
zone or be of a recognised type.
- Shock resistance
The motor can withstand a low mechanical impact (IK 08
according to EN 50102). The user must provide additional
protection if there is a risk of significant mechanical shock.
- Fitting sensors or accessories
In the event that sensors (vibration sensors for example) or
accessories (pulse generators for example) are fitted, these
must be connected in a panel. All these accessories (as well as
the panel if it not located outside the explosive atmosphere)
must be of a type that is certified or attested for the group, the
application (Gas or Gas and dust) and the temperature class
which corresponds at least to that of the motor. Fitting must
comply with the requirements of their instructions for use.
- Noise level
Most (F)LSN motors have an acoustic pressure level of less
than 80 dB(A) (+/- 3dB) at 50Hz.
The values for each motor are given in our technical catalogue.
When the motors operate using a drive, please contact us for
the noise levels.
INSTALLATION AND MAINTENANCE – LSN-FLSN ZONE 2 – Ex ec
