WEG ODP Instrucciones Para La Instalacion Y Mantenimiento página 6

The space heaters
energized while motor is running.
Drain plug position
Drain plugs
Insulation Resistance Checking
Disconnect motor
before making any insulation resistance
measurement.
To avoid electric discharge risks, discharge
the terminals right after performing the
measurement.
Measure the insulation resistance before
operating the motor and/or when there is any
sign of moisture in the winding.
The resistance measured at 25ºC must be:
Ri ≥(20 x U) / (1000 + 2P) [MΩ]
(measured with a MEGGER at 500 V d.c.)
where U = voltage (V); P = power (kW).
If the insulation resistance detected is less
than 2 M W, the winding must be dried
according to the following procedure:
Dismantle the motor and warm up the
frame and stator in an oven at a minimum
temperature of 80ºC increasing 5ºC every
hour until reaching 105ºC, remaining under
this temperature for at least one hour.
Check if the stator insulation resistance
remains constant within accepted values.
If not, stator must be reimpregnated. If
necessary, replace bearings and seals.
Notes:
1 - Measure the insulation resistance in
ambient temperature. If different than 25ºC
it should be corrected using the following
formula:
R(25°C) = [( K+25 ) / ( K + Ta )] . R(Ta)
should NEVER
Figure 1
from power supply
be Where:
R(25°C) = insulation resistance related to
25ºC ambient temperature
K = constant value 234.5 for copper
Ta = ambient temperature where the
resistance was measured
R(Ta) = resistance value measured in
ambient temperature Ta
4. INSTALLATION
4.1 – Safety.
All personnel involved with electrical installa-
tions, either handling, lifting, operation, start
up, maintenance or repair must be well in-
formed and updated concerning safety stan-
dards and principles that govern the work
and carefully follow them.
For practical reasons, it is not possible to
include in this Manual detailed information
that covers all constructive variables, nor
covering all possible assembly, operation or
maintenance alternatives.
For this reason, the present Manual only
includes required information that allows
qualified and trained personnel to carry out
the work.
If you still have further questions about it,
especially in reference to specific product
information, WEG is willing to provide such
information via its network of authorized ser-
vice agents and/or distributors.
In order to allow WEG to provide prompt ser-
vice, within technical standards, the motor
serial number that is available on the identifi-
cation nameplate should be supplied.
Use always appropriate tools for installation
and removal.
m
ake sure ThaT elecTric moTors
are swiTched off before sTarTing
any mainTenance service
All rotating parts such as pulleys, couplings,
outside fans, shaft, etc. must be protected
against accidental contacts.
Motors must be protected against unexpec-
ted starts.
When performing any maintenance service,
disconnect the motor from the power supply.
Make sure all accessories have been swi-
tched off and disconnected.
In order to prevent from penetrating dust
6
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