Eng
lish (US)
14
6. Starting up the product
During the process of welding or brazing the refrigerant pipe
system, impurities in the form of welding beads, burrs and grinder
disc fibers may be caught inside the pipes.
Clean the pipe system thoroughly from all impurities before
installing and starting the pump. Impurities can cause bearing
damage.
Always evacuate an installed pump before charging with
refrigerant. The pump must be completely filled with liquid
refrigerant before it is started. Do not allow dry running of the
pump, even for a few seconds.
6.1 Initial startup
The initial startup procedure for the CRN-H MAGdrive pump with
liquid refrigerant is detailed below. The pump is to be properly
installed and all electrical work completed (but not powered up).
Repeat this procedure for standby pumps.
1. Check for refrigerant leaks by pressurizing the pump and
piping.
2. Open the valve in the vent bypass line and the pump inlet
valve.
3. Verify the variable frequency drive is not powered up. Remove
the coupling guard from the pump and confirm the motor shaft
spins freely. Replace the coupling guard. The motor shaft
must spin freely before proceeding to the next step.
4. Follow the wiring diagram on the motor nameplate for the
correct motor wiring combination which matches your supply
voltage. Once this has been confirmed, connect the power
supply wiring to the motor.
5. Connect power to the frequency converter. Follow the
frequency converter setup process (including the basic
parameter setting and correct direction of rotation) which is
guided. The frequency converter will typically test both
directions of rotation and automatically determine the right
one. The pump family for the refrigerant pump is RC. The
direction of rotation is determined by the resulting phase order
of the power supply wiring. The CRN-H MAGdrive pumps
rotate counterclockwise when viewed from the fan of the
motor. If the pump is noisy, remove the power from the motor
immediately. The outlet pressure will fluctuate initially and
then remain steady. After programming CUE, copy the
settings to the Grundfos local control panel. Test the pump
protections (section
) while operating on
the bypass line, before proceeding to step 6.
6. Continue operating the pump and slowly open the pump outlet
valve. The outlet line will fill with liquid refrigerant.
The pumps are refrigerant-lubricated and do not require any
external lubrication or inspection.
The motors may require periodic lubrication as noted in section
Under no circumstances must the pump be operated for any
prolonged periods of time without flow through the pump. This
can result in motor and pump damage due to overheating.
6.2 Pump protection
All pump protection functions must be verified before you
complete the startup. The best method for testing the protection
functions must be determined depending on the installation. The
following general guidelines for testing the protection functions.
• Too low flow - close the outlet isolation valve and let the pump
operate on its bypass alone. Note the motor supply frequency
and the pump differential pressure. Use the pump
performance curve to verify that the operating condition falls
inside the acceptable operating envelope.
• Too low head - Close the inlet isolation valve to force operation
with too low head. Verify that the pump is stopped after about
20 seconds from the time the valve is closed.
Manually stop the pump, if the pump does not turn off in about 20
seconds.
• Too low NPSH - activate the liquid level switch and verify that
the pump stops immediately.
In case other protection functions have been established they
must also be tested before the pump is put in regular operation.
Motors must not be run unloaded or uncoupled from
the pump at any time. Damage to the motor bearings
may occur.
The pump outlet valve is to remain closed. The
refrigerant level in the inlet tank must be above the
minimum liquid level.
Liquid refrigerant will fill the pump from the inlet pipe.
The ammonia vapors will rise through the vent
bypass line.
Allow the pump to frost over. It may take over an
hour.
The pump is designed to pump liquid refrigerant not
vapors. Pump damage will occur if the pump is not
properly supplied with liquid refrigerant.
Summary of Contents for CRN-H MAGdrive
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