Flint & Walling 4 (10 cm) Stainless Commander Plus S Series - Manual (Page 6)

10
Copyright © 2014. All rights reserved • 95 North Oak St. • Kendallville, IN 46755
11
Copyright © 2014. All rights reserved • 95 North Oak St. • Kendallville, IN 46755
2. Transformer ratings should be no smaller than listed
in the table for supply power to the motor alone.
Open Wye or Delta systems often suffer from line
unbalance, which can cause poor motor performance,
nuisance overload tripping, or premature motor
failure. For the best performance current unbalance
should not exceed 5 percent. If the unbalance cannot
be corrected by rolling leads, contact the power
company.
Transformer Capacity Required for
Submersible Motors
Motor
HP
Total
Effective
KVA
Required
Smallest KVA Rating — Each
Transformer
Open WYE or
DELTA
2 Transformers
Closed WYE or
DELTA
3 Transformers
1-1/2
2
3
5
7-1/2
10
15
20
25
30
40
50
60
75
100
3
4
5
7.5
10
15
20
25
30
40
50
60
75
90
120
2
2
3
5
7.5
10
15
15
20
25
30
35
40
50
65
1
1.5
2
3
5
5
7.5
10
10
15
20
20
25
30
40
INSULATION RESISTANCE
Unbalance Formula
Percent
Current = Max difference from average x 100
Unbalance average
Example:
Currents are 80, 79, 84 amps (Lines 1-2 & 3)
Avg. Currents = 80 + 79 + 84 = 81
3
Percent
Current
Unbalance
84 - 81 x 100 = 3.7%
81
IL0104
Figure 13
Open Delta
Full Three Phase
Insulation resistance tests indicate the value of the motor,
cable, and splice insulation system by measuring
resistance in ohms between motor leads and ground.
Low readings indicate a breakdown somewhere in the
insulation system.
1. Set ohmmeter to RX100K or highest scale. (For best
results use a megohmmeter).
2. Short meter leads together and adjust indicator to
zero.
3. Be sure power is turned off!
4. Connect one meter lead to a motor lead and the other
meter lead to ground.
a. If motor is out of water, measure from lead to
motor frame.
b. If motor is installed in water, ground reference
should be metal well casing (if submerged), metal
drop pipe, or an extra wire extending into the
ground water.
5. Readings and Conditions, motor installed in well:
a. 2,000,000 ohms or more - insulation completely
acceptable.
b. 500,000 to 2,000,000 ohms - insulation in
reasonably good condition. Acceptable. Should
be considered marginal for new motor.
c. 20,000 to 500,000 ohms - insulation seriously
damaged, but motor may still operate.
d. Less than 20,000 ohms - severe insulation
damage. Motor probably not operable.
WINDING RESISTANCE
Winding resistance tests indicate whether or not windings
are internally correct, shorted, or open. Winding
resistance should be considered independently of
insulation resistance readings.
1. Set ohmmeter to RX1. Short meter leads together
and adjust indicator to zero.
2. Be sure power is turned off.
3. Connect ohmmeter between two motor leads.
Grounding Lightning Arrestors In Control Boxes
1. When the box has a lightning arrestor, it must be
grounded, metal to metal, all the way to the water
strata for the lightning arrestor to be effective.
Grounding the arrestor to a driven ground rod
provides little or no protection for the motor.
SUBMERSIBLE MOTOR COOLING
1. When the pump is set below any screen openings
or below the bottom of the casing a top feeding well
condition can exist which reduces the rate of cooling
water flow past the motor.
2. If the flow rate is less than specified a flow indicator
sleeve or an alternate method of increasing water
velocity past the motor must be used for proper
cooling.
Minimum Velocity Past the Motor
4” dia. motor – .25 ft./sec. (7.62 cm/sec)
6” dia. motor – .5 ft./sec/ (15.24 cm/sec)
3. A flow inducer sleeve is a tube over the motor, closed
off above the pump intake and extended to the bottom
of the motor or lower. The sleeve material is corrosion
resistant metal or heavy plastic (See Figure 12).
IL0103
Pump Body
Stainless Steel
Worm Gear Clamps
Intake Screen
Flow Inducer Screen
(Corrosion Resistant
Material)
Submersible Motor Centering Bolt
Corrosion Resistant
(3 Places)
All Water Flows
Past Motor
Figure 12
4. A flow inducer sleeve should always be used when
the pump is in an open body of water. Make sure
that such an installation is grounded.
Required Cooling Flow
Minimum GPM required for motor cooling in water
up to 86ºF (30ºC).
Inches
Casing or
Sleeve I.D.
4” High
Thrust Motor
.25 ft/sec
GPM
6” Motor
.5 ft/sec
GPM
8” Motor
.5 ft/sec
GPM
4
5
6
7
8
10
12
14
16
1.2
7
13
20
30
50
80
110
150
—
—
9
25
45
90
140
200
280
—
—
—
—
10
55
110
170
245
MAINTENANCE
SERVING SUBMERSIBLE MOTOR AND CONTROLS
1. The following is included to assist in motor installation
and servicing. These procedures are limited to the
motor and control system: they do not include pump
requirements.
TIGHTENING LEAD CONNECTOR JAM NUT
1. It is recommended that possible damage from removal
may prevent resealing. Torque the jam nut from 15 to
20 lb. ft. on 4” motor and 60 to 70 lb. ft. on a 6” motor.
CABLE IDENTIFICATION WHEN COLOR CODE IS
LOST
(Single Phase Only)
If the colors on the individual drop cables cannot be
determined and the leads cannot be positively identified,
proceed as follows:
1. Disconnect all three drop cables from the control box.
For temporary identification, tie a numbered tag to
each cable (1, 2, 3).
2. Using an ohmmeter, check the resistance
between cables as follows:
Unknown Value Known Value
Cable 1 to Cable 2
Cable 1 to Cable 3
Cable 2 to Cable 3
Lowest - Black to Yellow
Intermed. - Red to Yellow
Highest - Black to Red
NOTE: The “yellow” cable is that giving lowest and
intermediate readings and the “red” cables gives highest
and intermediate readings.
Example:
• 1 to 2 gives 7 ohms (highest reading)
• 1 to 3 gives 5 ohms (intermediate reading)
• 2 to 3 gives 2 ohms (lowest reading)
• Cable 3 gave both intermediate and lowest reading
• Cable 3 is the yellow cable
• Cable 1 gave both highest and intermediate readings
• Cable 1 is the red cable
• Cable 2 is the black cable
The actual ohm values are not important. The method
works regardless of the actual ohm readings; what
matters is which reading is highest, which intermediate,
and which lowest.
THREE PHASE POWER UNBALANCE
1. 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 from current unbalance.