Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control - Manual (Page 413)

Component Definition and Maintenance 6-69
7000 “C” Frame 7000L-UM300I-EN-P – June 2013
Non-Return Valves
The non-return valves (NV1 & NV2) shown in Figure 6.55 are ball-
type valves made from CPVC. These can not be changed with the
drive on-line. All coolant must be drained to replace these parts.
PI
PS
NV2
NV1
V11
From P1
From P2
V12
Figure 6.55 – Pressure Indicator and Switch Locations
Pressure Indicator
The pressure indicator (PI) shown in Figure 6.55 indicates the
discharge pressure of the pumps. Refer to Piping diagram supplied
for the expected pressure value. Diagram is pasted in the pump
cabinet.
Pressure Switch
The pressure switch (PS) shown in Figure 6.55 detects the drop in
pressure if a pump fails or if there is a major pipe break. When low
pressure is detected, the backup pump will start, but if the pressure
does not reach operating levels within a set period of time, the drive
will shut down.
The pressure trip setting is set at the factory and varies with the
construction of the drive.