| 1. |
Established 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 calculate
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
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:
- Add the three line amps values together.
- Divide the sum by three, yielding average current.
- Pick the amp value which is furthest from the average
current (either high or low).
- Determine the difference between this amp value
(furthest from average) and the average.
- 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 unbalance 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. |
|
|
 |
| |
| EXAMPLE: |
| T1 = 51 amps |
|
T3 = 50 amps |
|
T2 = 50 amps |
|
| T2 = 46 amps |
|
T1 = 49 amps |
|
T3 = 48 amps |
| + T3 = 53 amps |
|
+ T2 = 51 amps |
|
+ T1 = 52 amps |
|
|
|
|
|
| Total =
150 amps |
|
Total =
150 amps |
|
Total =
150 amps |
|
| |
150
3 |
= 50 amps |
|
|
150
3 |
= 50 amps |
|
|
150
3 |
= 50 amps |
|
| 50 - 46 = 4 amps |
|
50 - 49 = 1 amp |
|
50 - 48 = 2 amps |
| |
4
50 |
= 0.08 or 8% |
|
|
1
50 |
= 0.02 or 2% |
|
|
2
50 |
= 0.04 or 4% |
| |
Phase designation of leads
for CCW rotation viewing
shaft end. |
To reverse rotation, interchange
any two leads.
Phase 1 or "A"- Black, T1, or U1
Phase 2 or "B"- Yellow, T2, or V1
Phase 3 or "C"- Red, T3, or W1
|
| NOTICE: Phase 1, 2 and
3 may not be L1, L2 and L3. |
|
Page 32
