Recommended coolants
Ethylene glycol is a toxic compound. Avoid exposure to the coolant.
Copper ions concentration of more than approx. 0.06 ppm causes copper induced pitting
corrosion. Do not use copper components in the cooling system.
Hard piping made of metal is recommended for the coolant instead of soft piping as rubber
hoses.
Use correct personal protective equipment when you handle the coolant.
The electric machines are designed to work properly with water based coolant. Plain water with
appropriate corrosive inhibitor is acceptable, for example 50 % water- 50 % glycol coolant.
Glycol coolant options:
•
Ethylene glycol based Glysantin® G48® (includes also corrosion inhibitors).
•
Propylene glycol based coolants, like Splash® RV&Marine antifreeze.
Emergency operation
The electric machine should be operated within the operation limits and in the conditions specified by
the manufacturer. However, it can be used with some limitations in the following fault/emergency
situations.
Cooling of the electric machine fails
Cooling system failure can be caused by dregs (sediment) accumulating in the cooling system tubes. Try
opening the possible blockage by changing the coolant flow direction. See also Chapter
If the cooling of the electric machine fails, limited operation is still possible with no coolant flow. The
operation speed must be limited to half (1/2) of the rated speed and maximum 20 % of the nominal
torque may be used. In such case, the electric machine may be operated for maximum one hour. Repair
the cooling system as soon as possible. For further information, contact Danfoss representative.
The temperature measurement of the electric machine fails
The operation temperature of the electric machine is measured by PT100 temperature sensors in the
electric machine windings. The temperature signals can be read out from the measurement connector of
the electric machine, and connect to the temperature surveillance pin in the inverter for example. In case
of a temperature measurement sensor failure in the electric machine, an additional PT100 sensor can be
mounted close to the end of the windings at the low voltage (measurement signal) connector opening.
User Guide
EM-PMI300-T310
Operation
©
Danfoss | April 2023
BC265858156812en-000202 | 49
