Answer / rajan singh tanwar

This is based on
very simple
concept:-
It has three
letters and they
are coded as
follows:-

First Letter -
Operation
Quantity
A - Phase angle
comparison
B - Balanced Current
C - Current (Amps)
D - Differential
E - Direction
F - Frequency
K - Rate of rise of
current
M - Manual
O - Oil Pressure
P - Poly phase VA
R - Reactive VA
S - Slip Frequency
T - Temperature
V - Potential
W - Watts
X - Reactance
Y - Admittance
(Conductance)
Z - Impedance

Second Letter -
Measurement
A - Attracted
armature
B - Buchholz
C - Induction
D - Induction Disc
G - Galvanometer
I - Transmitter
J - Mixed Types
M - Magnet
(polarized)
P - Plug
R - Rectifier
S - Synchronized
Motor
T - Transistor
W - Weight (Gravity)

Third Letter -
Application
A - Auxiliary
B - Testing
C - Carrier or
Counting
D - Directional
E - Earth/Ground
F - Plug or Alarm
Indicator
G - General or
Generator
H - Harmonic
Restricted
J - Tripping
JE - Tripping
(Electrical
Reset)
JM - Tripping
(Manual
Reset)
JS - Tripping (Self)
JC - Tripping
(Conductor)
K - Check Alarm
L - Local Limiting
M - Same Phi or
motor
N - Negative
Sequence
O - Out of Step
P - Potential
Failure
R - Re-closing
S - Synchronizing
T - Timer or
Transformer
U - Definite Time
V - Voltage
Resistant
W - Piolet Wire
WA - Interposing
WS - Inter-tripping
X - Supervisory
Y - Flash Back
(Black
Fire)
Z - Special
Application
Z0 - Zero Sequence

Examples :
CDG - Current
(operation
), Disc
(Measurement),
General Purpose(
Application)
CAG - Current
(operation
), Attracted
armature(
Measurement),
General
Purpose(Application)
VAJ - Potential
(operation
), Attracted
armature(
Measurement),
Tripping(
Application)
VTT - Potential
(operation
), Transmitter(
Measurement),
Transformer
(Application)
VAZ - Potential (
operation),
Attracted
armature
(Measurement),
Special Application
VAA - Potential (
operation),
Attracted
armature
(Measurement),
Auxiliary
(Application)

Thanks I hope it
will help you.
Rajan Singh Tanwar
J.K.Cement Ltd.

Answer / tawumap ent

the first letter account for what is to be measured
the second letter is for the type of what causes the movement

so for the C part its for Current, for the V part its for
Voltage

The D is for disc operated. If u go and look closely on the
relays you will find an induction disc contained therein.

The other letters im going to figure out and tell you

Answer / k.prakashchandra

To add (As I remember)a few more. A- attracted armature
(Instantaneous), G- general purpose, H- high rupturing
capacity ( heavy duty),J- master trip,T- with timer and Z -
impedance

Answer / mithun mesta

J- Dc In comer
K- control,closing, Tripping
L- Alarm,Annunciation,
E- Potential Tranformer
H- AC supply
C- Protection Circuit
D- Metering Circuit
A- CT secondary for special protection

what are the types of transformers

59 Answers  

---

how  do you choose the cable size as per amps rating & the voltage drop for the same.

0 Answers   C&W,

---

how to test a motor from megger

5 Answers   JSW,

---

a starter used for squirrel cage induction motor?

0 Answers  

---

DOES AN EARTH FAULT CURRENT ON THE DELTA SIDE OF A 6.6/33KV STEP UP STAR-DELTA CONNECTED TRANSFORMER REFLECT ON THE STAR SIDE? IF YES, THEN HOW AND WHAT IS THE AMOUNT OF CURRENT REFLECTED?

1 Answers  

---

---

what is the use of spherical metal balls attached on to the earth wire of transmission over head lines?

2 Answers  

---

In industries Power factor is maintained by installing a suitable KVAR bank, How is the PF maintained for domestic use, where is the capacitor bank connected

3 Answers  

---

Mention the methods for starting an induction motor?

0 Answers  

---

what is the current generated in a 230v megger?

2 Answers  

---

If short circuit ratio is high is it bad or good for a machine then tell the reason...

0 Answers   Bhel,

---

What about electrical Units. discrive in detail

0 Answers  

---

How Negative Phase Sequence Relay works in case of Synchronous Motor?

4 Answers   L&T,

---