Xylem IM192R00 FloStandard SIMPLEX PUMP CONTROL PANEL - Manual (Page 6)

ITT
CENTRIPRO
Commercial Water Systems
• 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.
To calculate percent of current unbalance (see,
Example below):
1. Add the three-line amp values together.
2. Divide the sum by three, yielding average
current
3. Pick the amp value, which is furthest from
the average current (either high or low).
4. Determine the difference between this amp
value (furthest from average) and the aver-
age.
5. Divide the difference by the average. Multi-
ply the result by 100 to determine percent of
unbalance.
Current unbalance should not exceed 5% at ser-
vice factor load or 10% at rated input load. If the
unbalance cannot be corrected by rolling leads, the
source of the unbalance must be located and cor-
rected. 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.
Contact your local power company to resolve
imbalance.
Hookup 1 Hookup 2 Hookup 3
Starter Terminals L1 L2 L3 L1 L2 L3 L1 L2 L3
Motor Leads
T3 T1 T2 T2 T3 T1 T1 T2 T3
Example:
T3 = 51 amps T2 = 50 amps T1 = 50 amps
T1 = 46 amps T3 = 48 amps T2 = 49 amps
T2 = 53 amps T1 = 52 amps T3 = 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%
Main Power Supply
L1 L2 L3
Disconnect ‡
Starter
T1 T2 T3
Motor
‡ Class J Fuses are not included. Supplied by other vendors.
Figure 1 – Panel Connection Points