Xylem BMAID R4 - Manual (Page 41)

PAGE 41
Residential Water Systems
CentriPro
Hookup 1 Hookup 2 Hookup 3
L1 L2 L3 L1 L2 L3 L1 L2 L3
Starter
Terminals
T1 T2 T3 T1 T2 T3 T1 T2 T3
Motor R B Y Y R B B Y R
Leads T3 T1 T2 T2 T3 T1 T1 T2 T3
Example:
T3-R = 51 amps T2-Y = 50 amps T1-B = 50 amps
T1-B = 46 amps T3-R = 48 amps T2-Y = 49 amps
T2-Y = 53 amps T1-B = 52 amps T3-R = 51 amps
Total = 150 amps Total = 150 amps Total = 150 amps
÷ 3 = 50 amps ÷ 3 = 50 amps ÷ 3 = 50 amps
— 46 = 4 amps — 48 = 2 amps — 49 = 1 amps
4 ÷ 50 = .08 or 8% 2 ÷ 50 = .04 or 4% 1 ÷ 50 = .02 or 2%
thrEE phaSE powEr uNbalaNCE
A full three phase supply is recommended for all
three phase motors, consisting of three individual
transformers or one three phase transformer. So-
called “open” delta or wye connections using only two
transformers can be used, but are more likely to cause
problems, such as poor performance overload trip-
ping or early motor failure due to current unbalance.
Transformer ratings should be no smaller than listed
on Transformer Size Chart on previous page. phase designation of leads for CCw rotation view-
ing shaft end.
To reverse rotation, interchange any two leads.
Phase 1 or “A” – Black Motor Lead or T1
Phase 2 or “B” – Yellow Motor Lead or T2
Phase 3 or “C” – Red Motor Lead or T3
Notice: Phase 1, 2 and 3 may not be L1, L2 and L3.
Checking and correcting rotation
and current unbalance
1. Establish correct motor rotation by running in both
directions. Change rotation by exchanging any two
of the three motor leads. The rotation that gives the
most water flow is always the correct rotation.
2. After correct rotation has been established, check
the current in each of the three motor leads and cal-
culate the current unbalance as explained in 3 below.
If the current unbalance is 2% or less, leave the leads
as connected.
If the current unbalance is more than 2%, current
readings should be checked on each leg using each
of the three possible hook-ups. Roll the motor leads
across the starter in the same direction to prevent
motor reversal.
3. To calculate percent of current unbalance:
A. Add the three line amp values together.
B. Divide the sum by three, yielding average current.
C. Pick the amp value which is furthest from the aver-
age current (either high or low).
D. Determine the difference between this amp value
(furthest from average) and the average.
E. Divide the difference by the average.
Multiply the result by 100 to determine percent of
unbalance.
4. Current unbalance should not exceed 5% at service
factor load or 10% at rated input load. If the unbal-
ance cannot be corrected by rolling leads, the source
of the unbalance must be located and corrected. If,
on the three possible hookups, the leg farthest from
the average stays on the same power lead, most of
the unbalance is coming from the power source.
However, if the reading farthest from average moves
with the same motor lead, the primary source of
unbalance is on the “motor side” of the starter. In this
instance, consider a damaged cable, leaking splice,
poor connection, or faulty motor winding.
OPEN DELTA
OR WYE
FULL THREE
PHASE