Validity
This additional installation, operation and maintenance
manual is valid for Water cooled motors (M3LP 400 to
450) and is to be read together with the general manual
(Low Voltage Motors/Manual). Additional information
may be required for some machines due to special
application and/or design considerations.
Use
Normally, water cooled motors are manufactured to
specifi c customer requirements. However, these instruc-
tions refer to 'standard' water-cooled motor versions.
Handling
Should the motor be used or stored in environments
with risk of sub-zero temperatures, the water inside the
motor must be prevented from freezing. This can be
done either by emptying the water jacket or by using
anti-freeze additives.
Before emptying the water jacket, protect it with a
corrosion-protective emulsion, e.g. Esso Cutwell 40,
Shell Dromus Oil BS, or equivalent, in accordance with
the instructions given by the emulsion manufacturer. If
the motor has been standing for a long period of time
with no water, ensure that water can circulate freely
before using the motor again. Remove possible rust
blockages by dissolving them with oxalic acid:
1. Empty the frame of water.
2. Fill the frame with water mixed with oxalic acid
(100 g/liter).
3. Let the acid take effect for approximately 10 minutes.
4. Empty the frame and wash it with pressurized water.
5. Repeat the treatment if necessary.
If the motor is equipped with a separate bearing fan,
ensure that there is free ventilation airfl ow.
Water cooling
In motors type M3LP, waste heat is drawn off by water
circulating inside the motor housing. The water circu-
lates around the motor in a jacket inside the housing
and fl ows out through an outlet.
Motor frames have one water inlet and one outlet with
R 1'' threads in ND-end
(fi g 1).
Note! Read the cooling water instruction plate as well as
the markings for inlet and outlet pipes on the motor!
NOTE!
Only closed circuit water systems can be used in
compliance with the requirements specifi ed in the
following section.
EN – 2
Connection
Requirements for cooling water
Cooling water must be tap water quality. Sea water or
water with a proportion of chloride above 120 mg/l
should not be used. The highest allowed pressure for
cooling water is 5 bar, with a recommended maximum
input water temperature of 40°C.
The lower the cooling water input temperature, the
better the cooling of the motor.
For some cases a higher input temperature can be
allowed when requested and checked by the manufac-
turer.
The outlet water temperature rise is from 10-15 K.
The minimum pressure and amount of cooling water
the basic construction of a water cooled motor is shown
in the following table. Please check the requirements for
pressure and the amount of cooling water in the case of
special constructions.
(If the amount of water varies, its temperature rise will
be inversely proportional to the fl ow rate.)
Motor type
Number of
M3LP
inlets
Frame type
400 L_
1
450 L_
1
Filling or draining cooling water
When fi lling, open the air plug on top of the motor (fi g. 1).
Let the cooling water fl ow into the motor until it comes
out of the air gap. Close the air gap with a plug and seal
the joint with sealing tape or strip. Filling must be done
carefully so that no air is left in the motor's cooling
channels.
When emptying, open the emptying plug underneath the
motor and the air plug on top of the motor. After empty-
ing, the plugs must be re-fi tted and the seals of the
joints must be checked.
CAUTION!
The cooling water temperature may be high,
possibly exceeding even 70°C!
ABB / Low Voltage Motors / Add. manual for water cooled motors 06-2006
Cooling
Water
Water
water fl ow
pressure
temperature
rate (l/min)
min. (bar)
rise (K)
40
2.0
10-15
50
2.0
10-15
for