6
provides basic information for the correct connection and
loading of the transformer. The following is a brief de
scription of the information supplied on a typical name
plate (See Figure 1 ).
1. SERIAL NUMBER: Use this number to identify a
specific transformer when communicating with Westing
house.
2. VOLTAGE: The voltage shown is the rated terminal
to-terminal voltage.
3. FREQUENCY (Hertz cycles/second): This is the fre
quency at which the transformer is designed to operate.
4. COOLING CLASS: This is the method of cooling used
to dissipate the heat generated during operation.
5. KV A: This is the amount of power (or capacity) the
transformer can transmit without overheating.
6. TEMPERATURE RISE (°C): This is the average wind
ing rise above ambient temperature.
7. INSTRUCTION BOOK: The instruction book that
applies to the transformer.
8.
GALL O N S O F F L U I D A N D APPROXIMATE
WEIGHTS: This information is itemized so that maximum
untanking as well
as
total weights are known. Liquid vol
ume of each separate compartment is specified to give the
required storage capacity if the unit needs draining.
9. IMPULSE LEVELS: This is the full wave BIL (basic
insulation level) in kilovolts of the line and neutral termi
nals.
10. IMPEDANCE: This is the percent impedance meas
ured by test. Impedance is of particular importance when
paralleling transformers. Refer to Section 7.2.6.
11. WINDING CONNECTION DIAGRAM: A winding
connection diagram is provided to show the relative loca
tion of bushings and internal terminals.
12. CONNECTION CHART: This chart gives the voltage,
current and connection of each tap changer position,
series multiple or Delta/Wye switch position, and of inter
nal terminal boards, when present.
13. NOTES AND WARNINGS: The notes below the
connection chart contain important information for use in
operation and maintenance. Read the notes because spe
cial features or warnings will be in the nameplate notes.
14. PHASE RELATION: The phase rotation and phase
angle shift between the high voltage and low voltage is
represented by a phasor diagram.
5.4 Liquid Level Gauge
The liquid level indicator consists of a floatarm inside the
tank, an indicating pointer and a magnetic coupling be
tween the two across a liquid-tight barrier. If the dial is
damaged, the outer bezel may be replaced without dis
turbing the rest of the instrument without loss of liquid.
Fig. 2
Bezel with Alarm (left); Body with Float and Rod
at Back (center); Bezel without Alarm Contacts
The gauge may be furnished with a Single Pole, Double
Throw microswitch enclosed in the bezel to give a remote
annunciation of low liquid level. Alarm switch ratings are
in Table
l,
page 4.
While complete instruments with or without contacts
are interchangeable for a given size device, a bezel with
alarm contacts should not be used on a body which was
intended for use with a bezel having no alarm contacts. A
larger and stronger magnet must be used in the body of an
instrument when alarm contacts are in the bezel.
When indicators are installed at the factory, the tank is
filled to the level which corresponds to a liquid tempera
ture of 25°C which is considered the normal level. Should
the tank be f:tlled at some temperature other than 25°C,
use Table 2 to determine the variation above or below the
normal level. If these allowances are not made, excessive
pressure may be built up in sealed tanks.
The indicator is usually shipped mounted on the trans
former case and requires no maintenance other than the