7929 SW Burns Way Phone: 503 344-5085
Suite F
Wilsonville, OR sales@cascadiamotion.com
1/14/2021 RMS PM Hardware User Manual 9 of 54
For proper operation of the inverter the coolant must flow at a rate equal to or above the
minimum specified flow rate at all times that the motor is enabled. The flow rate should not
be reduced when the inverter is “not being run hard”. The design of the heat exchanger
does not allow for reduced or no coolant flow. It is possible to adjust the fan speed on the
coolant radiator as needed depending on the operating conditions of the inverter.
Since the maximum coolant temperature is less than the boiling point of water the cooling
system does not need to be operated under pressure. Other devices (e.g. motor, charger,
DC/DC converter) that are added in series with the inverter increase the total pressure drop
of the system. Even simple fittings and hose length will contribute to the total system
pressure drop. The total system pressure may add up to a level that is beyond the
capability of the chosen pump. The best practice is to measure the actual coolant flow
after the system has been assembled.
Certain pump types are not capable of driving any significant pressure. A pump may have
a high flow rate, but it may not be able to drive any substantial pressure. The PM250 unit
has an especially high pressure drop. An example pump suitable for the PM250 is the
EMP WP 29. Pump suitable for the PM100/PM150/RM100/CM200 is the Bosch PCE-XL
(see Cascadia Motion website).
As noted above proper coolant flow is essential to the operation of the inverter. If the flow
rate is not sufficient the power module internal to the inverter can be damaged even though
the indicated power module temperatures are below an over-temperature threshold. The
power module temperature sensors are located in such a way that they are much closer to
the temperature of the coolant than they are to the temperature of the transistors
and diodes used inside the power module.
Loss of coolant for even a few seconds can result in failure of the power module.
Cascadia Motion recommends that the user install a device to ensure that the coolant pump
is operating properly at all times when the inverter is enabled. The inverter should be
immediately stopped if the coolant is not flowing.
There are many ways that coolant flow could be measured. A flow sensor could be added
to the cooling loop. Often these types of sensors produce a pulse output. To read the
pulse output would require the use of a device to interpret this signal (Cascadia Motion does
not supply this).
To Next Page
Loading...
Need help?
General
