Pentair Pentek Series User Manual

11
4.7 Using a Generator
Selecting a generator
Select a generator that can supply at least 65% of rated
voltage upon start-up of the motor.
The chart shows ratings of generators, both externally
and internally regulated. This chart is somewhat
conservative. Consult the generator manufacturer if you
are uncertain.
Table 4-3: Ratings of Generators
Motor Externally Regulated Internally Regulated
HP kW KVA kW KVA
1/2 2.0 2.5 1.5 1.9
3/4 3.0 3.8 2.0 2.5
1 4.0 5.0 2.5 3.1
1-1/2 5.0 6.3 3.0 3.8
2 7.5 9.4 4.0 5.0
3 10.0 12.5 5.0 6.25
5 15.0 18.8 7.5 9.4
7-1/2 20.0 25.0 10.0 12.5
10 30.0 37.5 15.0 18.8
15 40.0 50.0 20.0 25.0
20 60.0 75.0 25.0 31.0
25 75.0 94.0 30.0 37.5
30 100.0 125.0 40.0 50.0
40 100.0 125.0 50.0 62.5
50 150.0 188.0 60.0 75.0
60 175.0 220.0 75.0 94.0
Frequency
It is highly important that the generator maintain
constant frequency (Hz), since the motor’s speed depends
uponfrequency.
A drop of just 1 to 2 Hz can noticeably lower pump
performance. An increase of 1 to 2 Hz can cause
overloadconditions.
Voltage Regulation
There is a significant difference in the performance of
internally and externally regulated generators.
An external regulator senses output voltage dips
and triggers an increase in the voltage output of the
generator.
An internal regulator, senses current and responds to
increased current by supplying more voltage.
Generator Operation
Start the generator before starting the pump motor.
The pump motor must be stopped before turning off
thegenerator.
If the generator runs out of fuel, and the pump is still
connected, it will put excess strain on the thrust bearings
as the generator slows.
Risk of electrocution. Use transfer
switches when the generator is used as a backup to the
power grid. Contact your power company or generator
manufacturer for proper use of standby or backup
generators.
4.8 Special Applications
Using Phase Converters
Phase converters allow three-phase motors to operate
from one-phase supply. Various styles of phase
converters are available. Many converters do not supply
a properly balanced voltage, and using these will void the
motor’s warranty unless approval is obtained first.
Guidelines For Phase Converters:
• Currentunbalancemustbelessthan5%.
• Convertertobesizedtoservicefactorcapacity
• Maintainmotorcoolingwithacoolingflowofatleast
3’ per second.
• Fusesandcircuitbreakersmustbetime-delaytype.
Motor Starting with Reduced Voltage
Starting a motor with full voltage will bring it to full speed
in less than 1/2 second. This can:
• Spiketheloadcurrent,causingbriefvoltagedipsin
other equipment.
• Over-stresspumpandpipingcomponentsbecauseof
high torque.
• Causewaterhammer.
Motor Starters (3-Phase Only)
Various types of motor starters are available.
Autotransformers are recommended because of reduced
current draw.
When motor starters are used, they should supply
a minimum of 55% of rated voltage for adequate
startingtorque.
SECTION 4: Electrical Power
Electrical Power

Pentair Pentek Series Specifications

General

Brand	Pentair
Model	Pentek Series
Category	Engine
Language	English