WARNING
Dangerous voltage at the isolating cylinder
The isolating cylinder separates exposed circuits from high-voltage circuits. Interfering with
the structure and connections of the isolating cylinder can result in death, severe injury and
considerable material damage.
Do not change the structure of the isolating cylinder.
3.3.1.6
Door limit switches
Door limit switches monitor the doors. The circuit breaker opens when a door is opened.
The door interlocking system prevents access to the power unit while operational. The following
conditions must be fulfilled in order to open the doors: For additional information, see Chapter
"Opening the device (Page 117)".
3.3.1.7
Cooling unit
Operating principle of the re-cooling unit
The re-cooling unit dissipates the heat loss from the drive. The deionized water in the internal
water circuit absorbs the heat of the drive power unit which is to be dissipated. A maintenance-
free circulating pump pumps the hot water into the heat exchanger. The external raw water
circuit cools the hot deionized water. The cooled deionized water is pumped back to the drive.
Internal de-ionized water circuit
The internal water circuit is filled with deionized water (deionized, fully-desalinated water). The
conductivity of the cooling water must be ≤ 1 µS/cm in operation.
NOTICE
Material damage due to inadmissible additives in the deionized water
Inadmissible additives in the deionized water can cause the cooling system to fail. This could
damage the drive.
• Use only deionized water that corresponds to the specifications. The specification of the
deionized water can be found in the documentation for the re-cooling unit.
• The level in the deionized water expansion tank and the pump motor circuit breakers are
monitored. Any water leak is also detected.
• The pressure of the deionized water is displayed on a manometer. If the flow is excessively
low, then the re-cooling unit automatically switches over the pumps.
Description
3.3 Power unit
3rd Party LCI Control Upgrade
28
Operating Instructions, 02/2022, A5E31872818
