Page 5
60706-160 REV 3
3117-30
THE GENERATOR IS ON STANDBY, AND MUST ISOLATE
THE COMMERCIAL POWER LINES FROM THE LOAD AND
THE GENERATOR WHEN THE GENERATOR IS SUPPLYING
POWER. SEE FIGURE 5.
Operation
OUTPUT POWER AVAILABLE AND LOAD DETERMINATION
Before using the generator, read and understand the following
information.
Generator output current (amperage) is internally limited by
three circuit breakers. If too much demand is placed on a
generator output (if you try to drive too many motors with it, for
example), one of the circuit breakers will trip, cutting off the
output in order to protect the generator.
A 15 amp push-to-reset circuit breaker protects the 120V
duplex receptacle output circuit. 15 amps is the total limit for
both outputs of the duplex receptacle. (Not available on the
480 volt three phase generators.)
A 50 amp two pole switch type circuit breaker protects the
240V receptacle output circuit. (Not available on the 480 volt
three phase generators.)
A large two pole (three pole for three phase) switch type main
circuit breaker protects the generator windings and output
circuits, including the load disconnect receptacle. (On the
W135PTOS, W145PTOT and the 150PTOS you will connect
your power output leads directly to the mainline circuit
breaker.)
To aid in determining how much load can be applied to the
generator, and how it should be distributed among the
generator output receptacles, the following formulas may be
useful. Get load voltage, current, and wattage from the
nameplates on the equipment in the load.
(Load Current, in amps) x (Load Voltage) = (Load Wattage)
AMPS X VOLTS = WATTS
WATT/1000 = kW
(Load Current in amps) = (Load Wattage)/(Load Voltage)
Example:
250W, 120V floodlight load = 250W/120V= 2 amps (parrots.)
NOTE:
Electric motors require much more current to start than to run.
Commonly, the current rating given on a motor nameplate is
the full load (running) current required by the motor, not its
starting current, which is a lot higher. Motor starting current
requirements vary greatly, by motor size and type. Repulsion-
induction type motors are the easiest to start, typically using 1
1/2 to 2 1/2 times as much current to start as to run; capacitor
type motors usually require 2 to 4 times as much current to
start as to run; split-phase type motors are the hardest to start,
normally using 5 to 7 times as much current to start as to run.
MOTOR LOAD
SINGLE PHASE
THREE PHASE
Motor
Amps
Amps
Amps
Amps
Horsepower
115V
230V
208
240
(Running Amps)
(Running Amps)
1/4
5.8
2.9
1/3
7.2
3.6
1/2
9.8
4.9
2.3
2.0
3/4
13.8
6.9
3.2
2.8
1
16
8
4.15
3.6
1-1/2
20
10
6.0
5.2
2
24
12
7.8
6.8
3
34
17
11
9.6
5
56
28
17.5
15.2
7-1/2
80
40
25
22
10
100
50
32
28
20
62
54
40
120
104
Compiled from N.E.C. manual.
To use the full capacity of the generator without tripping its
circuit breaker(s), start the motors in the load one at a time,
highest starting current motor first, next highest second, etc.
Use the preceding table as a source of general information
about motor running current requirements. For more specific
information, see motor nameplate or motor manufacturer’s
catalog.
PRE-START CHECKS
WARNING: Personal Injury
When working on or around these generators, do not wear
loose fitting clothing or any articles that may get caught in
moving parts.
1. Visually inspect the generator. Check for:
a. Correct mounting
b. Physical damage
c. Debris in cooling vents and screens (could
cause generator to overheat).
IMPORTANT
: The manufacturer recommends that, if the
generator has been stored for any length of time, before using
it, the operator remove the control box cover and cooling fan
screen, then inspect the generator for rodent nests or other
objects that could cause generator binding and/or
overheating. See “Cleaning” portion of Maintenance section.
2. Check gear case oil level. (See Figure 6.) Case should be
filled with oil to plug marked “OIL LEVEL.” Fill or remove oil as
required.
NOTE
: EITHER TOO LITTLE OR TOO MUCH OIL CAN HARM
THE EQUIPMENT.
See “Lubrication” portion of Maintenance for oil specifications.