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English (US)
8. Servicing the product
8.1 Maintaining the product
The CRN-H MAGdrive pump is essentially maintenance-free.
During operation, there is no need to dismantle the pump to
inspect the pump parts as long as no problems have occurred. If
it becomes necessary to dismantle and inspect or replace the
pump, the operation is easy, as the pump volute can remain
connected to the pipe system. There is no need to open the
flange connections between the volute and the inlet and outlet
pipes. The only reasons for dismantling the pump are the
following:
• impeller is blocked.
• replacement of chamber stack or MAGdrive components.
In case of mechanical or electrical failure, contact your local
Grundfos company for ordering replacement parts.
8.2 Motor inspection
Inspect the motor at regular intervals, approximately every 500
hours of operation or every three months, whichever occurs first.
Keep the motor clean and the ventilation openings clear. The
following steps must be performed at each inspection:
1. Check that the motor is clean. Check that the interior and
exterior of the motor is free of dirt, oil, grease, water, etc. Oily
vapor, paper, pulp, textile lint, etc. can accumulate and block
motor ventilation. If the motor is not properly ventilated,
overheating can occur and cause early motor failure.
2. Use an ohmmeter ("Megger") periodically to ensure that the
integrity of the winding insulation has been maintained.
Record the ohmmeter readings. Immediately investigate any
significant drop in insulation resistance.
3. Check all electrical connectors to be sure that they are tight.
In the case of seasonal operation (motor is idle for more than
six months of the year), we recommend that you grease the
motor when the pump is taken out of operation.
WARNING
Switch off the power supply and lock the power
supply in position OFF before starting maintenance
work on the pump.
WARNING
The system must be evacuated before dismantling
the pump.
Before dismantling the pump, close the stop valves
on either side of the pump.
Do not close valves that seal off a pipe section
unless that section is protected by a pressure-limiting
device (e.g. a safety valve). Expansion of trapped
liquid refrigerant in a pipe section without pressure-
limiting devices can led to bursting of pipes or
components. Refrigerants can be flammable and/or
toxic and must be recollected.
CAUTION
O-rings in contact with refrigerants often change
dimensions and therefore will not fit correctly into the
O-ring grooves. When dismantling a pump that has
been in contact with refrigerants, the O-rings must be
replaced.
WARNING
When emptying and evacuating a system containing
a liquid refrigerant, the refrigerant boils and absorbs
heat from the parts it is in contact with. As heat is
absorbed, the temperature of these parts drops
significantly. Once the evacuation is completed, the
temperature of the parts can remain low for a period
of time. If a pump is to be removed from a system
that has just been evacuated, use extreme caution,
protective clothes (e.g. thermal gloves, safety
glasses), and avoid touching the internal parts until
the temperature is close to the ambient temperature.
WARNING
Elevated concentrations of refrigerants (above
atmospheric level) can influence the respiration rate
of persons and cause nausea and discomfort.
Transportation and-or storage of a pump, motor and
chamber stack or pump sleeve containing
refrigerant-in a closed environment (e.g. the cabin of
an automobile) must be avoided.
Summary of Contents for CRN-H MAGdrive
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