Xylem BMAID R4 - Manual (Page 30)

PAGE 30
Residential Water Systems
CentriPro
thrEE phaSE motor opEratIoN oN VfD'S
Variable frequency Drive’s (VfD) can be used with the 3 phase Centripro motor provided the operator
meets the following criteria:
1) Maintain frequencies from 30HZ – 60HZ. Do not operate below 30HZ for more than 1 second. 80 HZ
operation can be used.
2) Ensure VFD is a PWM, IGBT, Volts per Hz scalar type and does not produce more than 500 volts dV/dT.
3) Use a load reactor (load filter) of 3% impedance or more on motor lead lengths of 50 wire feet or more. The
Balanced Flow product already includes this in all models.
4) Follow all NEC, state, local or provincial electrical codes for Power Conversion Equipment wiring and
installation.
5) Provide appropriate dedicated short circuit protection. Properly sized fuses or breaker disconnects.
6) Size wire according to NEC, state, local or provincial codes OR refer to manufacturers recommendation for
wiring sizing.
7) Ensure proper flow around motor.
8) Maintain proper grounding of the motor back to drive and service entrance. Common ground throughout
system!
the following are some installation issues we have seen on returned balanced flow controllers which
factory re-testing has shown to operate perfectly:
Symptom Cause
• Cycling, won't turn off, poor pressure control Incorrect tank pre-charge pressure
• Cycling and wide pressure swings Larger than recommended tank
• Poor performance Motor running backwards
Performance Improvement Suggestions:
• Installing a spring check valve on the pump side of the tank can reduce time to standby when flow stops.
• Poor pressure control can be caused by a clogged sensor. Not an issue for sensors 4/09 and later.
• Updating controllers built prior to 4/09 with latest Software, UIB and Sensor will improve reliability and
performance.
• Updating software in controllers built after 4/09 may improve performance.
• Many generators produce voltages that exceed the 264VAC max rating of the controller. Test the generator
output voltage when no load is connected. If the voltage exceeds 264VAC, do not use it with the BF
controller!