Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control - Manual (Page 425)

Component Definition and Maintenance 6-81
7000 “C” Frame 7000L-UM300I-EN-P – June 2013
To rectify the problem, add small quantities of water. Measure the
freeze temperature of the coolant after each addition and continue
adding until the desired freezing temperature is achieved.
Leakage Checks
When repairing leaks or working on the stack assemblies, it is highly
recommended that several layers of industrial-grade absorbent pads
be placed on top of the middle and lower stacks to prevent any coolant
spills from falling down on to the lower components, specifically the
printed circuit boards.
Most leaks will be visible in the first 30 minutes, and once the
system begins to fill and pressurize, you should be constantly
inspecting all fittings and connections for drips. It is best to have
help in checking the inverter and rectifier section, and the DC Link
cabinet. An absorbent cloth is ideal for checking that the coolant is
actually leaking and is not just remnants of the repair.
If a leak is a visible at the threaded joint of a stainless steel fitting
and a CPVC (plastic) pipe, the leak can often be repaired by
tightening the joint.
Use the following values of torque when tightening stainless
threaded fittings into CPVC.
Thread Size Torque N-m (lb-ft) Typical Wrench Size
l/4 inch NPT 9,5 N-m (7.0 lb-ft) 15 mm (9/16 inch)
3/8 inch NPT 9,5 N-m (7.0 lb-ft)
19 mm (3/4 inch) and
26 mm (1 inch)
1/2 inch NPT 27 N-m (20 lb-ft) 29 mm (1-1/8 inch)
If a leak persists, it will be necessary to drain the system, disassemble
the threaded joint, clean the threads and reassemble with a generous
amount of Teflon paste applied to the threads.
No matter how well you drain the system with the pumps, be aware
that there will be liquid in the tubes, manifolds, and chill blocks.
This requires special care in removing connections, as there will
definitely be liquid leaking out. Use absorbent pads or containers to
catch the liquid.
System Drain
Turn off the pumping system and disconnect the switch on the
cabinet door. Attach the transfer pump to Drain/Fill line. Ensure that
the flow arrow on pump is in the correct direction. Open valve V6
and V7 to Pump coolant out.