9
3GZF500725-144 EN 03-2023 | ABB IEC LV MOTORS
8.
Water cooling
In motors type M3LK, waste heat is drawn off by water circulating inside the motor housing.
The water circulates around the motor in a jacket inside the housing and flows out through
an outlet.
Motor frame has one water inlet and one outlet with R 1" threads (see figure 2).
Note!
Read the cooling water instruction plate as well as the markings for inlet and outlet pipes on
the motor!
9.
Connection
9.1.
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 wa-
ter temperature of 45 °C. Steel frame water- cooled construction is only to be used with a
closed fresh-water circulation. The cooling water circulates in ducts integrated in the machine
frame. The material of the frame and ducts is carbon steel according to the standard EN
10025-S235_ or -S355. This material is prone to corrosion in saline and foul water.
The corrosion products and fouling deposits might block the water flow in the ducts. That’s
why it is important to use pure water in the cooling system.
Standard values for the cooling water to be used in the cooling system:
•
pH 6.5–9.5
•
Alkalinity (CaCO3) > 1 mmol/l
•
Chloride (Cl) < 120 mg/l
•
Conductivity < 1500
μ
S/cm
In most cases, normal tap water, i.e. water for domestic consumption, meets all these
requirements.
The cooling water can also be inhibited with an agent protecting the cooling system against
corrosion, fouling, and, when necessary, against freezing. All materials in contact with the
cooling water (pipes, heat exchanger, etc.) must be considered when selecting a suitable in-
hibitor.
Use only suitable and high-class connection parts and seals to connect the machine to the
water circuit.
In environments with risk of sub-zero tempera- tures, a glycol/water mixture can be used
with 40/60 mixture (glycol/water), with a recom- mended minimum environment tempera-
ture of -20 °C.
The lower the cooling water input temperature, the better the cooling of the motor.
