GE CLPG12C User manual

INSTRUCTIONS
CARRIER CURRENT GROUND RELAY
CLPG12C
GENERAL ELECTRIC
GEI-8391OG

GEI-83910
TABLE OF CONTENTS
PAGE
INTRODUCTION
........................ . . . . . . . . . . . . . . . . . . . . . .. ....... 3
APPLICATION .............................. . . . . . . . . . . . . . 3
RATINGS .......................... ......... 4
COILS ......... ....... ................................... 4
CONTACTS ................ ....................................... 4
CHARACTERISTICS ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
OPERATING PRINCIPLES .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
PiCKUP................. .......................... ...... ........ 5
OPERATING TIME ................................................... 5
BURDEN
................ .......................................... 5
CALCULATIONS OF SETTINGS ............................................... 5
TWO-TERMINAL LINE ...................................................... 6
THREE-TERMINAL LINE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6
CONSTRUCTION ............... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
CARRIER-START UNIT (G-1) ................................................. 7
TRIP UNIT (G-2) ........... . . . . . . . . . . . . . . . . . . . . . . . .. .................. 8
DIRECTIONAL UNIT (GD) ................................................... 8
AUXILIARY UNIT (GD1X) ................................................... 8
SEAL-IN UNIT (SI) ................... . . . . . . . . . . . . . . . . . . . . . . 9
RECEIVING, HANDLING, AND STORAGE .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
ACCEPTANCE TESTS ............................................................ 9
VISUAL INSPECTION ................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
MECHANICAL INSPECTION ................................................ 10
ELECTRICAL
TESTS ........................................................ 10
Upper-Unit Pickup (G1) ........................ ............... 10
Middle-Unit Pickup (G2) ........... . . . . . . . . . . . . . . 11
Bottom-Unit Pickup (GD) ........... . . . . . . . . . . . . . . . . . . . .. 11
Bottom-Unit-Core Check (GD) ....... . . . . . . . . . . . . . .. 11
GD1X Unit Pickup ........................ . . . . . . . . . . . . . . . . . . . . . .. 11
INSTALLATION PROCEDURE .......... ....................................... 11
RELAY SETTINGS .................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
CARRIER-PICKUP-START UNIT (G1) .... ................................... 12
CLUTCH ADJUSTMENT........ .................................... 12
TRIP UNIT (G2) .......................................................... 12
CLUTCH ADJUSTMENT
.................................................... 13
DIRECTIONAL UNIT (GD) ........................ . . . . . . . . . . . . . . . . . .. 13
PERIODIC CHECKS AND ROUTINE MAINTENANCE. . .. . . . . . . . . . . . . . .. 13
MECHANICAL CH ECKS ............................. 14
ELECTRICAL TESTS ............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14
SERVICING .................................................... . . . . . .. 14
MECHANICAL ADJUSTMENTS ....................................... 14
ELECTRICAL ADJUSTMENTS . . . . . . . . . . . . . . . 15
RENEWAL
PARTS... .......... ...................................... 16
LIST OF FIGURES...... ........ .......................... 17
(Cover Photo 8029772)
)

GEI-83910
CARRIER CURRENT GROUND RELAY
CLPG12C
I NTRODUCTI ON
The CLPG12C is a high-speed, zero-sequence ground relay designed specifically
for use as a ground-fault relay in directional-comparison relaying schemes. This
relay contains one high-speed zero-sequence directional unit, which may be
po 1 ari zed from voltage and/or current. It also contains two hi gh-speed zero-
sequence non-directional overcurrent units and one direct-current-operated (DC)
aux il iary unit. The CLPG12C is packaged ina size-L2 case and incl udes a target
and a separate seal-in unit. One CLPG12C is required per terminal.
APPLICATION
The CLPG12C finds application on grounded neutral systems as the directional-
comparison ground relay in directional-comparison schemes, regardless of the type
of channel
that is used. This relay, operating in conjunction with the pilot
channel and the CLPG12C relays at the other ends of the protected 1ine section,
provides high-speed tripping for all single-phase-to-ground faults in the protected
line section.
The two non-di rect i ona 1 overcurrent uni ts and the operat i ng ci rcuit of the
directional unit may be all supplied in series from the neutral connection of the
three line-current transformers. The polarizing circuit of the directional unit
may be supplied from a current transformer in the neutral of a grounded neutral
power transformer or from the broken-delta secondary connection of three potential
transformers whose primary windings are connected in wye, or it may be
simultaneously supplied from both sources of polarization.
These instructions do not purport to cover all details or variations in equipment nor provide {or every
possible contingency to be met in connection wilh inst.allation, operation or maintenance. Should {urther
in{ormation be desired or should particular problems arise which are not covered sufficiently for the purchaser's
purposes, the matter should be referred to the General Electric Company.
To the ex/ent required the products described herein meet applicable ANSI, IEEE and NEMA
standards; bllt no such assurance is giuen with respect to local codes alld ordinances because they vary greatly.

GEI-83910
The
sensitivity of each of the overcurrent units, as well as that of the
directional unit, is adjustable over the ranges specified under RATINGS. The
operating times of the three units are given in the CHARACTERISTICS section. !\
complete elementary diagram for a directional-comparison scheme over a carrier
channel including the CLPG12C may be obtained from the local district office.
Figure 2 shows typical external connections.
RATINGS
The potential coils of the CLPG12C relay are rated 120 volts intermittent and
360 volts for 10 seconds, both values being at rated frequency.
The CLPG12C relay is available in either of the following ratings at either 50
or 60 Hz.
Gl Unit
G2 Unit GD Unit GD Unit
Range Range Range Range
in in
V x I I x I
Amperes Amperes
Potential Current
Polarization Polarization
0.4 - 1.6
0.5 - 2/1
- 4
3.6 -
57.6 0.25 - 4.0
0.8 - 3.2
1 - 4/2 - 8
3.6 - 57.6
0.25
- 4.0
The angle of maximum torque is 80" ± 2" (I lags V) when the unit is potential-
polarized. If it is current-polarized, the angle of maximum torque is 10" ± 10" (I
pol lead lop).
If the unit is set for 0.25 (IxI), then the unit will pick up when VxI = 4.5 ±
15%. If a 3.6 VA pickup is required, then the control spring should be adjusted so
that the contact will just close when 3.6 VA is applied at the angle of maximum
torque.
The auxiliary-telephone-relay unit (GDIX) is available in continuous ratings
of 48 or 110 or 125 or 250 vo lts DC. The current ci rcu its are rated 3 amperes I,
cont i nuous and 140 amperes for one second. The 140 ampere rat i ng is also the
max imum permi ss ib1e current. The target-and-sea 1- in coil s with a one (1) ampere
rating will carry 30 amperes for tripping duty and 2.5 amperes continuously. The
target··and-seal-in units with ratings of 0.6 ampere DC wi 11 carry 30 amperes for
tripping duty and 0.9 amperes continuously.
CONTACTS
The tripping contacts of this relay are the normally-open contacts of the G2
and GD units. They wi 11 carry 2.5 amperes cont i nuous ly and wi 11 c1 Dse and carry 30
amperes DC for tripping duty at control voltages of 250 VDC or less. The breaker-
trip-coil circuit should, however, always be opened by a circuit-breaker auxi liary
switch or' other suitable means. If the tripping cUlTent exceeds 30 amperes, ,in
auxi liary tripping y'eliJy should be used.
,

GEI-83910
CHARACTERISTICS
OPERATING PRINCIPLES
The three main units of the CLPG12C relay are of the high-speed efficient
eight-pole cup structure. They most closely resemble an induction motor, except
that the rotor iron is stationary whi 1e the rotor conductor port i on (the cup) is
free to rotate.
PICKUP
The relays can be set to pick up, i.e. close the N.O. Contacts, at the values
of
current shown in the RATINGS section. The method of adjusting pickup is
described in the INSTALLATION PROCEDURE section.
OPERATING TIME
Figure 3 shows the operating time of the two overcurrent units (Gl and G2) as
a function of operating
current. Figure 4 shows the operating time of the
directional unit (GO) as a function of multiples of product pickup.
TABLE I
60 C.P.S. CURRENT BURDENS AT MINIMUM Gl PICKUP
MEASURED BURDENS IN
OHMS IMPEDANCE AT:
Gl Transformer
Gl
G2 Tap
R X Z 5
10
20 60
Circuit Connection Rating
Range
Ohms Ohms Ohms Amps Amps Amps
Amps
Amps Amps
Operating Shunt
0.4-1.6 0.5-2 0.80 1.84 2.00 2.00 1.80 1.50 0.95
(Studs 3-4) Shunt
0.4-1.6 1 - 4 0.60 1.36 1. 50 1.50 1.20 1.00 0.70
Stepup 0.4-1.6 0.5-2 2.44 3.42 4.20 4.20 3.10 2.20 1.20
Stepup 0.4-1.6 1 - 4 2.12 3.12 3.80 3.80 2.60 2.00 1.10
Shunt
0.8-3.2
1 - 4 0.30 0.70 0.76 0.76 0.70 0.57 0.40
Shunt 0.8-3.2 2 - 8 0.23 0.52 0.58 0.58 0.50 0.42 0.31
Stepup
0.8-3.2
1 - 4 0.73 1.04 1.26 1.26 1.20 1.05 0.75
Stepup
0.8-3.2
2 - 8 0.64 0.94 1.14 1.14 1.00 0.80 0.50
Polarizing
All All All 0.25 0.04 0.26 0.26 0.23 0.21 0.20
(Studs 5-6)
8URDEN
The burdens imposed on the current transformers are shown in Table I. The
capacitive potential circuit burden, calculated at 120 volts, 60 Hz, is shown in
the following table:
Potential Circuit Burdens
WATTS
VARS
VOLT AMPERES
18
3.18 18.35

The burdens imposed by the
for the comparable 60 Hz relays.
given in the following table:
DEVICE UNIT
Target
Seal-In
Target
Seal-In
GEI-83910
50 Hz relays are approximately 90% of those shown
The resistance of the target and seal-in units is
RATING RES. 25°C
1 A 0.34 Ohms
1 A 0.28 Ohms
0.6A 0.73 Ohms
0.6A 0.72 Ohms
___ ----.:_~ ___ :...:.... __ ---------.J
CALCULATIONS OF SEITINGS
It is
cond it ions.
follows:
not possible to give specific settings for the CLPG12C relay for all
However, a general guide for setting the three units of this relay
TWO-TERMINAL LINE
GO UNIT: Set for minimum pickup (maximum sensitivity). Check to ensure pickup for
all si ngl e-phase-to-ground fau lts on the protected 1i ne with 1ine breakers closed
at both terminals. Use dual polarization where facilities permit.
Gl UNIT: The preferred pickup setting is the minimum rated pickup value of this
unit. Do not set higher than 80% of the G2 pickup setting at the remote end of the
line. t)
G2 UNIT: Set pickup no higher than 67% of minimum single-phase-to-ground fault
current in the relay with the remote breaker closed. Lower pickup settings are
permissible, and in most cases desirable for increased speed of operation.
However, do not set pickup lower than 125% of the Gl pickup setting at the remote
end of the 1 ine.
THREE-TERMINAL LINE
GO UNIT: Set for minimum pickup (maximum sensitivity). Check to ensure pickup for
all si ngle-phase-to-ground faults on the protected 1i ne with the 1i ne breakers
closed at all three terminals. Use dual polarization where facilities permit.
Gl UNIT: The preferred pickup setting is the minimum rated pickup value of this
unit. However, when current outfeed can exist for internal faults, an attempt
should be made to set the pickup above the value of outfeeding current at that
terminal. In any event this unit should not be set higher than 40% of the G2
pickup settings at the two remote terminals.
\i~_~lnI: Set pickup no higher than 67% of the minimum single-phase-to-ground fault
current in the relay with both rl~mote line breakers closed. Lower pickup settings
are permissible, and in most Cilses desirable for increased speed of operation.
However, do not set pickup lowey' than 250% of the Gl pickup settings at the two
remote terminals.
6

GEI-8391O
CONSTRUCTION
The three main units (G1, G2, and GO) of the elPG12e relay covered by these
instructions are of the induction-cup construction.
This is the top unit of the eLPG12e relay. It has two electrically separate
contacts. The right-hand (front view) contact is closed when the unit is de-
energized. When energized, the unit operates to open its right-hand contact and
then closes its left-hand contact.
The four corner coils of the unit consist of two windings each. The inner
windings consist of a large number of turns of fine wire, and the outer windings
have a few turns of heavy wire. The inner windings are connected in series with a
capacitor to form a phase-shift i ng ci rcu it. The outer wi nd i ngs are connected in
series internally, and into the operating-current circuit externally. The four
side coils are similarly connected into the operating-current circuit.
To increase the torque output for sensitive settings of the Gl unit (1-2 times
minimum pickup), there is provided in the elPG12C relay a 2:1 autotransformer. The
transformer, when connected as a step-up transformer, effectively doubles the
current in the G1 unit.
The increased torque thus requires additional control-spring windup, thereby
i ncreas i ng the force on the norma lly-c lased (carri er-start) contact. The net
result is to reduce or eliminate the possibility of spurious carrier signals due to
shock or vibration when sensitive settings are employed on this unit.
As a further aid in reducing the possibility of spurious carrier signals, the
carrier-start contact is of the low-gradient construction.
The low-gradient contacts of the Gl unit are shown in Figure 5. Both the
stationary and the moving contact brushes are made from low-gradient material.
When subjected to vibration they tend to follow one another, thus resisting contact
separation.
The contact di a1 (A) supports the stat ionary contact brush (B) on whi ch is
mounted a conical contact tip (e). The moving-contact arm (0) supports the moving-
contact brush (E) on which is mounted a button contact tip (F). The end of the
moving-contact brush bears against the inner face of the moving-contact-brush
retainer (G). Similarly, the end of the stationary-contact brush bears against the
inner face of the stationary-contact-brush retainer (H). The stop (J), mounted on
the contact dial, functions to stop the motion of the contact arm by striking the
moving-contact-brush retainer after the moving- and stationary-contact members have
made contact. The stationary-contact support (K) and the contact dial are
assembled together by means of a mounting screw (l) and two locknuts (M).
The normally-open contact is of the standard barrel type of construction.
The barrel-type contacts shown in Figure 6 are especially constructed to
suppress bouncing. The stationary contact (G) is mounted on a flat spiral spring
(F) backed up by a thin diaphragm (e). These are both mounted in a slightly
inclined tube (A). A stainless steel ball (8) is placed in the tube before the
diaphragm is assembled. When the moving contact hits the stationary contact, the
energy of the former is imparted to the 1 atter and thence to the ball, whi cn is

GEI-83910
free to roll up the inc1 ined tube. Thus, the moving contact comes to rest with
substantially no rebound or vibration.
The moving contacts are supported on a molded plastic arm that is attached to
the rotor shaft. The arm is held from rotating freely by a control spring. This
spring maintains a torque in the
direction to hold the normally-open contacts open
by a magnitude that determines the pickup of the unit.
B. TRIP UNIT (G-2)
This is the middle unit of the CLPG relay and is similar in construction to
the Gl unit previously described. This unit has two electrically separate
contacts. The 1eft-hand contact is closed when the unit is de-energized. When
energized, the unit operates to open its 1eft-hand contact and then closes its
right-hand contact. It further differs from the Gl unit as follows: -
The Gl unit has its corner coils and side coils connected in series
internally. However, the G2 unit side- and corner-coil connections are brought out
to a tap block located at the side of the G2 unit. This tap block arrangement
permits the
G2 unit coils to be connected in series or parallel, depending on the
tap chosen. This allows the
unit to have two ranges of pickup.
Both the normally-open and normally-closed contacts of the G2 unit are of the
barre1-type construct ion previ ous1 y described. Furthermore the G2 unit does not
use
an auxiliary current transformer.
C. DIRECTIONAL UNIT (GO)
This is the bottom unit of the CLPG relay. It has 2 electrically separate
contacts of the barrel-type constructi on previous 1y described. When de-energized,
the right-hand contact
is closed. When energized in the tripping direction, the
unit operates to open the right-hand contact and then closes the left-hand contact.
The stator has eight 1 ami nated magnet ic po 1es project i ng inward and arranged
symmetrically around a
central magnetic core. The poles are fitted with current
and potential coils. Three of the corner coils are connected internally to form a
single circuit for current polarization. Each of these coils has two windings, one
of which carries the polarizing current. The other winding is connected in series
with the corresponding winding of each of the other two coils, with a capacitor.
The resultant flux from these coils is shifted in phase with respect to the
operating-circuit flux. The fourth corner coil is a potential coil for potential
polarization. The four side coils are connected together to form the operating-
current circuit.
In the annular air gap between the poles and central core is the cylindrical
cup-like part of the aluminum rotor, which turns freely in the gap. The rotor
shaft is supported at the bottom by a steel pivot that projects downward through a
bronze guide beari
ng mounted in the end of the shaft. The shaft carri es the
movable contact
arm through which the contact circuits are completed.
D. AUXILIARY UNIL.0DIX)
This unit is located in the rear of the CLPG12C relay, just below the upper
unit.

GEI-83910
It is a telephone-type relay unit with adjustable time--delay pickup. T[,e unit
is preset at thf' factory for 16-18 milliseconds time--delay pickup. f\ copper slug
on the armatli,-e end of the core delays the flux buildup, and consequently the relay
I,ickup. DrolJOut time is approximately 88 milliseconds. One normally-closed
contact and OIIC normally-open contact of the unit are brought out to separate studs
fOl" external cir'cuH control. The resistor', R?, is connected dcross the GOIX coil
when it is used on 220 or 250 VDC.
E. SEAL-IN UNIT (SI)
This unit is located in the upper right-hand corner (rear view) of the relay.
It is of the familiar hinged-armature construction and operates to lift and close
its contacts, whenever sufficient trip current flows in its operating coil.
The above units and associated components are mounted on a steel cradle
assembly that can be easily removed from the relay case.
The crad1e is locked in the case by means of 1atches at the top and bottom.
The electrical connections between the case block and cradle block are completed
through a removable connection plug. A
separate testing plug can be inserted in
p
Iace of the connecti on plug to permit test i ng the re1 ay in its case. The cover
attaches to the case from the front and includes the target reset mechanism and an
interlock arm to prevent the cover from being replaced until the connection plug
has been
inserted.
The case is suitable for either semi flush or surface mounting on panels up to
two inches (2") thick. Hardware is available for any panel thickness up to two
inches, but panel thickness must be specified on the order to ensure that the
proper hardware will be provided. Outline and panel-drilling dimensions are shown
in Figure 14.
RECEIVING, HANDLING, AND STORAGE
These re1ays, when not inc1 uded as part of a contro1 pane1, wi 11 be shi pped in
cartons designed to protect them against damage. Immediately upon receipt of a
relay, examine it for any damage sustained in transit. If injury or damage
resulting from rough handling is evident, file a damage claim at once with the
transportation company and promptly notify the nearest General Electric Sales
Office.
Reasonable care should be exercised in unpacking the relay in order that none
of the
parts are injured nor the adjustments disturbed.
If the relays are not to be installed immediately, they should be stored in
their original cartons in a place that is free from moisture, dust, and metal 1 ic
chips. Foreign matter collected on the outside of the case may find its way inside
when the cover is removed, and cause trouble in the operation of the relay.
Q

GEI-83910
ACCEPTANCE TESTS
Immediately upon receipt of the relay, an examination and tests should be made
to make sure that no damage has been sustained in shipment and that the relay
calibrations have not been disturbed. If the examination or tests indicate that
readjustment is necessary, refer to the section on SERVICING.
VISUAL INSPECTION
Check the nameplate to make sure that the model number, rating and calibration
range of the relay recei ved agree with the requ i sit ion. Remove the re1 ay from its
case and check that there are no broken or cracked molded or compound parts, and
that all screws are tight.
MECHANICAL INSPECTION
It is recommended that the following mechanical adjustments be checked:
1. There should
be no noticeable friction in the rotating structure of each unit.
The normally-closed contacts should be closed when the relay is in an upright
position.
2. There should be an end play of from .005 to .015 inch on the shafts of the
rotat i ng structures. The lower jewe l-screw beari ng of each unit should be
screwed firmly in place, and the pivot at the top of the shaft should be
locked by its set screw.
3.
The contact gap on each unit should be approximately 0.020 inches.
4.
The target shield should drop freely when the armature is pushed against the
pole piece.
With the cover fastened securely in place, check that the target
resets positively when the reset button at the bottom of the cover is
operated.
5. The armature and contacts of the seal-in unit should move freely when operated
by hand. There should be at least 1/32" wipe on the seal-in contacts.
6. Check the location of the contact brushes on the cradle and case blocks
against the internal-connection diagram for the relay (See Figure 13). Be
sure that the shorting bars are in the proper locations on the case blocks,
and that the long and short brushes on the cradle block agree with the
internal-connection diagram. Figure 8 shows a sectional view of the case and
cradl e blocks with the connecti on plug in place. Note that there is an
auxiliary brush in each position on the case block. This brush should be
formed high enough so that when the connecting plug is inserted, it engages
the
auxiliary brush before striking the main brush. This is especially
important in current circuits and other circuits with shorting bars, since an
improper adjustment of the auxiliary brush could result in a CT secondary
circuit being momentarily open-circuited.
ELECTRICAL TESTS
Upper-Unit Pick~~
Check that the green lead is connected to terminal #3 and that the black lead
is connected to terminal #3A. See internal diagram Figure 13.
10