Grundfos BMPX, Installation And Operating Instructions Manual

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18.3 X-Changer
Warning
Before starting work on the X-Changer, make sure that the electricity supply has been switched off and that it cannot
be accidentally switched on.
Fault Cause Remedy
1. Excessive sound
pressure levels.
a) The X-Changer operates above rated flow
rates on low-pressure side, high-pressure
side or both.
Immediately reduce flow rate by adjustment of the
BM hp circulation pump and control valve (V2). Balance
the system as described in section
11.6 Balancing the
X-Changer .
b) The X-Changer operates with little or no
back-pressure.
Increase the back-pressure by adjusting the low-
pressure reject-water valve (V3). Re-balance the
system as described in section
11.6 Balancing the X-
Changer .
c) Air in system. Vent the system.
2. Excessively high
recovery in the SWRO
system.
a) The BMP hp feed pump is operating at too
high a flow rate.
Verify that the main BMP hp feed pump flow rate does
not exceed the membrane array production capacity for
a given temperature, salinity and fouling factor.
b) Excessively high recovery in the SWRO
system.
Increase and balance flows through the X-Changer.
Do not exceed recommended maximum flow rates.
c) Low-pressure flow is less than high-pressure
flow resulting in mixing and high feed water
salinity.
See section 11.6 Balancing the X-Changer .
3. High salinity in high-
pressure sea-water
feed stream.
a) Unbalanced system. See section 11.6 Balancing the X-Changer .
b) A jammed or stalled rotor short-circuits high-
pressure reject water with high-pressure
feed water. No exchange occurs; no audible
rotation.
See fault number 5.
4. Low-pressure flow is
less than high-pressure
flow resulting in mixing
and high SWRO feed
water salinity.
a) Operating the X-Changer below rated flow
rate results in low rotor rotation and
increased mixing.
Increase and balance flows through the X-Changer.
Do not exceed recommended maximum flow rates.
See section
11.6 Balancing the X-Changer .
b) Malfunctioning and/or stalled BM hp
circulation pump.
Check BM hp circulation pump rotation, operation, flow
rates and pressures.
5. Stalled rotor
(no audible rotation).
a) Operating system above rated pressure or
below rated flow capacity.
See section 11.6 Balancing the X-Changer .
b) Foreign debris or particles lodged in device. Contact Grundfos Service.
c) System is not properly flow-balanced. See section 11.6 Balancing the X-Changer .
6. Low reject flow. a) Excessive pressure losses through the
SWRO system.
Contact Grundfos.
b) Malfunctioning and/or stalled BM hp
circulation pump.
Check operation, flow rates and pressures of the BM hp
circulation pump.