Caution, Technical data, Generator sizing – Xylem IM103 R03 5 and Larger Submersible Pump User Manual
Page 10: Generator sizing generator recommendations, Generator recommendations

10
Technical Data
MOTOR INSULATION RESISTANCE READINGS
Normal Ohm/Megohm readings, ALL motors, between all leads and ground
Condition of Motor and Leads
OHM Value
Megohm Value
New motor, without power cable
20,000,000 (or more)
20.0
Used motor, which can be reinstalled in well
10,000,000 (or more)
10.0
Motor in well – Readings are power cable plus motor
New motor
2,000,000 (or more)
2.0
Motor in reasonably good condition
500,000 to 2,000,000
0.5 – 2.0
Motor which may be damaged or have damaged power cable
Do not pull motor for these reasons
20,000 to 500,000
0.02 – 0.5
Motor definitely damaged or with damaged power cable
Pull motor and repair
10,000 to 20,000
0.01 – 0.02
Failed motor or power cable
Pull motor and repair
Less than 10,000
0 – 0.01
CAUTION
To perform insulation resistance test, open breaker and disconnect all leads from QD control box or
pressure switch. Connect one ohmmeter lead to any motor lead and one to metal drop pipe or
a good ground. R x 100K Scale
Technical Data
Note: Always consult the generator
manufacturer when questions arise.
These sizing charts are recommendations based on motor
service factor loading for typical continuous duty generators. If
you need to call the generator manufacturer, be prepared to tell
them the motor KVA code, the service factor amperage, locked
rotor amperage, phase, hertz, motor type, etc.
You must know which type generator you have before using the
charts as the required generator size varies by type. Internally
regulated generators are also called self-excited. Externally
regulated generators are the most common. In addition to the
Kw/KVA rating, the generator frequency (Hertz, typically
60 HZ in USA) is very important when operating pumping
equipment because frequency variations affect pump output in
direct relation to the pump Affinity Laws. Operating under 60
hertz will reduce flow and head while operating over 60 hertz
will increase flow, head, HP and amp draw and could overload
the motor.
The generator should always be started before the pump/
motor is started and always stop the pump/motor before
shutting down the generator. Operating generators at higher
elevations or using natural gas as fuel can affect performance,
consult the generator manufacturer for their recommendations
in these instances.
Generator Sizing
Generator Sizing
Generator Recommendations
Externally Regulated
Internally Regulated
Motor HP KW KVA KW KVA
Minimum Generator Rating
.5
2
2.5
1.5
1.9
.75 3 3.8 2 2.5
1
4
5
2.5
3.2
1.5 5 6.3 3 3.8
2
7.5
9.4
4
5
3
10
12.5
5
6.3
5
15
18.8
7.5
9.4
7.5 20 25 10 12.5
3-Wire
10 30 37.5 15 18.8
1Ø
15 40 50 20 25
and
20 60 75 25 31
3Ø
25 75 94 30 37.5
Motors
30
100 125 40 50
40
100
125
50
62.5
50
150
188
60
75
60
175
220
75
94
75 250 313 100 125
100 300 375 150 188
125 375 469 175 219
150 450 563 200 250
175 525 656 250 313
200 600 750 275 344
Generator Recommendations