
SEBU8219-01 63
Operation Section
Generator Operation
Generator Options
Space Heaters
Most of the SR4B generators are provided with
space heaters. These space heaters are installed
for operation in high humidity conditions. For more
information on space heaters, refer to Maintenance
Section, “Space Heater - Check”.
Embedded Temperature Detectors
SR4B generators are available with embedded
temperature detectors. The detectors are installed in
the slots of the main armature. The main armature is
alsocalledastator.Thedetectorsareusedwiththe
equipment that is provided by the customer. Thus,
the temperature of the main armature winding can be
measured or monitored. Three types of temperature
detectors are available. Contact your Caterpillar
dealer for more information.
Bearing Temperature Detectors
Bearing temperature detectors are available as an
option on SR4B generators. Bearing temperature
detectors measure main bearing temperature.
Bearing temperature detectors are used with the
equipment that is provided by the customer. Thus,
the temperature of the bearing can be measured or
monitored. Bearing temperature measurements may
help to prevent premature bearing failure. Two types
of temperature detectors are available. Contact your
Caterpillar dealer for more information.
i02324949
Parallel Operation
SMCS Code: 4450
Initial Start-Up
Preparing a generator for parallel operation requires
special attention. Before you attempt to parallel units
for the first time, check all the units for the following
three conditions.
•
same phase rotation
•
same alternating current frequency
•
same voltage adjustment
1. Check the phase rotation.
Units that oper
ate in parallel must have the same
phase rotation. There are two methods that may
be used in order to determine if the incoming unit
and the unit th
at is on-line have the same phase
rotation. These methods are listed below:
•
using a phase
rotation meter
•
using a set of three light bulbs
Use the procedure below to determine the proper
phase rotation by using three light bulbs.
g00695380
Illustration 56
When servicing or repairing electric power gener-
ation equipment:
Make sure the unit is off-line (disconnected from
utility and/or other generators power service), and
either loc
ked out or tagged DO NOT OPERATE.
Remove all fuses.
a. Connect th
e light bulbs with rated voltage
between the generator leads and the
corresponding line phase. For example,
connect t
erminal 1 to line 1 across the open
circuit breaker.
b. Start the
units that will be in operating in
parallel. Bring the units up to speed. As the
units approach the same speed, the lights will
start to
blink.
•
If the lights blink in sequence, one of the
units is
connected backward. In order to
correct the problem, stop the units. Remove
generator leads 1 and 3 at the circuit
breaker
. Exchange these generator leads.
This reverses the direction of phase rotation.
Terminal 2 should always be connected to
line 2.
Go to 5.