GE CAP15A User manual

INSTRUCTIONS
GEI-12083J
POWER DIRECTIONAL RELAYS
Types
(APl SA
(APlSI
GENERAL _ ELECTRIC

GEI-12083
TABLE OF CONTENTS
APPLICATION . .
RATINGS ....
12CAPI5A(-)A
12CAP15B(-)A.
CONTACT RATINGS ..
SHORT TIME RATINGS ..
POTENTIAL COIL RATINGS.
TARGET AND HOLDING COILS.
OPERATING CHARACTERISTICS
BURDENS ...
CURRENT . . . . . . . . .
POTENTIAL . . . . . . . .
CONSTRUCTION ....... .
RECEIVING, HANDLING AND STORAGE
PERIODIC CHECKS AND ROUTINE MAINTENANCE
CONTACT CLEANING ...... .
POWER REQUIREMENTS - GENERAL·
ELECTRICAL TESTS ..... .
DRAWOUT RELAYS - GENERAL.
ACCEPTANCE TESTS ..
LOCATION ..... .
MOUNTING ..... .
CONNECTIONS . . . .
INSTALLATION TESTS.
OPERATION . . . .
ADJUSTMENTS . . .
CUP AND STATOR ..
ACCEPTANCE TESTS •.
HOLDING COILS . . . .
CONTROL AND LEAD-IN SPRING.
CLUTCH - 12CAP15B(-)A .
CLUTCH - 12CAP15A(-)A .
SERVICING - 12CAP15A(-)A.
MECHANICAL ADJUSTMENTS.
POLARITY TESTS. . . . .
PHASE ANGLE TESTS . . .
SERVICING - 12CAP15B(-)A.
ME CHAN I CAL ADJ USTMENTS .
POLARITY TESTS. .
PHASE ANGLE TESTS .
CORE ADJUSTMENTS ..
PIC KUP ADJ US TMENT .
HOLDING COIL CHECK.
TARGET CHECK ...
HI-POTENTIAL TEST
RENEWAL PARTS . . . .
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GEI-12083
The Type CAP15A and Type CAP15B relays consist of one three-phase unit, with one rotor mounted on a
shaft. The contact assembly consists of two electrically separate contacts, one normally-open and one
normally-closed. The normally closed contacts are held closed, when the relay is not energized, by means
of two spiral springs which also complete the control circuit to the moving contacts.
APPLICATION
The CAP15A relay is a three-phase induction-cylinder power directional relay. Its principal application
is to perform the directional duties in directional overcurrent scheme. The recommended A-C external wiring
connection
for the Type CAP15A relay are shown in Figure 9, connection A. I~ith this connection the relay
has maximum torque on a balanced three-phase condition when the line current lags its unity power factor po-
sition by 40 degrees in the tripping direction. On a zero voltage phase-to-phase fault just beyond the
relay terminals, the relay has maximum torque when the current laqs its unity power factor position by 70
degrees in the tripping direction. Figure 2 demonstrates the directional characteristics of the preferred
connection (60 degree connection). The 30 degree and 90 degree connections are also shown in Figure 9,
with the corresponding angle
of maximum torque for balanced conditions.
If the relay is used in an application where there is the possibility of a momentary reversal of power
immediately following the clearing of a fault, and if the overcurrent relay contacts have closed, it is
necessary to provide directional control to prevent false tripping. In the case of time-delay overcurrent
relays, this may be done by allowing the overcurrent relays to operate only if the fault is in the pro-
tected direction. If the overcurrent relay is instantaneous in operation, discriminating control may be
obtained by using the right-hand contact to contrr~ a Type HGA auxiliary relay as shown in Figure 3.
If both directional contacts are used and if a momentary reversal of power immediately following the
clearing of a fault is not possible, it is still advisable to use some method of directional control.
This is evident because when a fault is removed, sufficient energy will be stored in the deflected contact
to caus~ rebound to the other contact. If only one contact is being used, the stored energy in the other
contact may be substantially eliminated by reversing the contact barrel and its sleeve in the contact hol-
der thereby using the
back end 'as a solid stop. This is done by loosening the screw that locks the barrier
in place, remove the barrel and sleeve, unscrew toe sleeve from the Barrel, insert the sleeve into the con-
tact support from the inside and screw the barrel into it from the outside with the contact pointing cut.
When the stop is located where desired, lock in position by tightening the screw. It has been found ad-
visable to remove the corresponding moving contact finger as well.
The Ty~o CAP15B relay is a general purpose reverse power relay. This relay measures true watts and is
practically unaffected by the reactive component of power. Because this relay is a high speed relay, it
should always be used with a suitable timing relay in order to prevent undesired operations during system
disturbances
which cause momentary power reversals. An application of the CAP15B is shown in Figure 13.
RATINGS
12CAP15A(-)A
The 12CAP15A(-)A relays are available at voltage ratings of 115, 130, 208 and 230 volts. The current
circ~its are continuously rated at five amperes with frequencies available at 25, 35, 50 and 60 hertz.
The targets and holding coils are available at 0.2 and 1.0 amperes d-c rating.
12CAP15B(-)A
The 12CAP15B(-)A relays are available at voltage ratings of 115, 208, and 230 volts. The current
circuits are continuously rated at five amperes with frequencies available at 25, 50 and 60 hertz. The
targets and holding coils are available at 0.2 and 1.0 ampere d-c rating.
These instructions do not purport to cover all details or variations in equipment nor to provide for
every possible contingency to be met'in connection with installation, operation or maintenance. Should
further information 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 extent required the products described herein meet applicable ANSI, IEEE and NEMA standards;
but no such assurance is given with respect to local codes and ordinances because they vary greatly.
3

GEI-12083
CONTACT RATINGS
The contacts of both types of CAP relays can momentarily carry 30 amperes for voltages not exceeding
250 volts. However, the contacts do not have an interruptin~ rating. Therefore, the trip circuit must
be opened by some other means.
Each stationary contact, Figure 6, is mounted on a flat spiral spring (F) backed up by a thin dia-
phragm (Cl. These are both mounted in a slightly inclined tube (A). A stainless steel ball (B) is
placed into the tube before the diaphragm is assembled. \~hen the moving contact hits the stationary
contact, the energy of the former is imparted to the latter and thence to the ball, which is free to roll
up the inclined tube. Thus, the moving contacts come to rest with substantially no rebound or vibration.
To change the stationary contact brush, remove the contact barrel and sleeve as a complete unit after
loosening the screw at the front of the contact block. Unscrew the cap (E). The contact brush can then
be removed.
SHORT TIME RATINGS
The current coils of all the CAP relays have a one second rating of 220 amperes. To determine the
current that can be applied for more than one second, the following f ltion can be used.
12t = K K=
2202 = 48400/1 second
I = IT
Applied current
t Time in seconds
POTENTIAL COIL RATINGS
The potential coils of all the CAP relays are continuously rated at their nameplate voltage value.
TARGET AND HOLDING COILS
The rating for the target and holding coil are given in the following table I
TABLE I
AMPERES A.C. OR D.C.
FUNCTION
1
AMP 0.2 AMP
Coil Resistance 0.25 ohm D.C. 7.0 ohm D.C.
Tri ppi ng Duty 30
5
Carry Continuous 1.25* 0.5
*Determined by the control spring rating.
The 0.2 ampere coil is for use with trip coils that operate on currents ranging from 0.2 ampere to
one ampere at the minimum control voltage. If this coil is used with trip coils that take one ampere or
more, there is a possibility that the seven ohms resistance will reduce the tripping current to a low
value and then the breaker will not trip. This coil can safely carry tripping currents as high as five
amperes.
The one ampere coil should be used with trip coils provided the tripping current does not exceed 30
amperes at the maximum voltage. If the tripping current exceeds 30 amperes, an auxiliary relay must be
used to control the trip-coil circuit. It must be connected in such a manner that the tripping current
does not pass through the contacts or the target and holdinq coil of the protective relay.
When it is desirable to adopt one type of relay as standard to be used anywhere on a system, relays
with the
one ampere coil should be chosen. These relays should also be used when it is impossible to
obtain
trip coil data, but attention is called to the fact that the tar~et may not operate if used with
trip coils taking less than one ampere.
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G~I-12083
OPERATING CHARACTERISTICS
The phase angle and time characteristics of the 60 cycle relay are shown in Figures 1, 1A and 2 with
the
recommended connections.
BURDENS
CURRENT
The burden imposed by each current coil at five amperes is given in the table below. With standard
connections,
one of the three current transformers supplies two current coils in series so that the burden
on that transformer will be twice the amount given below. The other two current transformers will each
supply
one current coil and will have a burden as given in the following table:
TYPE CAP15A
Frequency Volt
Amps ~Iatts P. F.
60 0.40 0.20 0.50
50
0.35 0.20 0.57
25 0.60 0.55 0.92
TYPE CAP15B
60
3.6 1.8
0.50
50 3.2 1.8 0.57
25 2.6 2.4 0.92
POTENTIAL
The potential burdens per relay circuit (studs 13-14, 15-16, 17-18 and 19-20) are listed in the
following
table.
Relay Frequency Volt
Amps Watts
P. F.
CAP15A
60
5.3 1.60 0.30
50 6.2 2.15 0.35
25
3.5 1.85 0.53
CAP15B
60 4.7 2.35 0.50
50 5.8 2.89 0.50
25 3.5
1.85 0.53
CONSTRUCTION
The stator has eight laminated magnetic poles projecting inward and arranged symmetrically around a
central magnetic core. The poles are fitted with current and potential coils. In the annular air gap
between the coils and the central core, is the cylindrical part of the cup-like aluminum rotor, which
turns freely in the air gap. The central core is fixed to the stator frame and the aluminum cup rotates
carrying the moving contacts.
This construction provides a higher torque and a lower rotor inertia than the induction disk construc-
tion, and makes the relay faster and more sensitive than the disk-type relays.
The CAP relays are contained in an S2 drawout case providing a means to remove the relay from the
circuitry without disconnecting any wiring.
The outline and panel drilling diagram is shown in Figure 15.
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GEI-12083
RECEIVING, HANDLING AND STORAGE
These relays, when not included as a part of a control panel, will be shipped 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 Apparatus Sales Office.
Reasonable care should be exercised in unpacking the relay in order that none of the parts are injured
or 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 metallic 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.
PERIODIC CHECKS AND ROUTINE MAINTENANCE
In view of the vital role of protective relays in the operation of a power system, it is important
that a periodic test program be followed. It is recognized that the interval between periodic checks will
vary depending
upon environment, type of relay and the user's experience with periodic testing. Until the
user
has accumulated enough experience to select the test interval best suited to his individual require-
ments,
it is suggested that the points listed under INSTALLATION PROCEDURE be checked at an interval of
from one to two years.
CONTACT CLEANING
For cleaning relay contacts, a flexible burnishing tool should be used. This consists of a flexible
strip of metal with an etched-roughened surface resembling in effect a superfine file. The polishing action
is so delicate that no scratches are left, yet it will clean off any corrosion thoroughly and rapidly. Its
flexibility insures the cleaning of the actual points of contact. Do not use knives, files, abrasive paper
or cloth of
any kind to clean relay contacts.
POWER REQUIREMENTS - GENERAL
All alternating current operated devices are affected by frequency. Since non-sinusoidal waveforms
can be analyzed as a fundamental frequency plus harmonics of the fundamental frequency, it follows that
alternating current devices (relays) will be affected by the applied waveform.
Therefore, in order to properly test alternating current relays it is essential to use a sine wave
of current and/or voltage. The purity of the sine wave (i.e., its freedom from harmonics) cannot be ex-
pressed as a
finite number for any particular relay; however, any relay using tuned circuits, R-L or RC
networks, or saturating electromagnets (such as time-overcurrent relays) would be essentially affected
by non-sinusoidal wave forms.
Similarly, relays requiring d-ccontrol power should be tested usingd-c and not full wave rectified
power. Unless the rectified supply is well filtered, many relays will not operate properly due to the
dips in the
rectified power. Zener diodes, for example. can turn off during these dips. As a general
rule, the d-c source should not contain more than 5 percent ripple.
ELECTRICAL TESTS
DRAWOUT RELAYS GENERAL
Since all drawout relays in service operate in their cases,it is recommended that they be tested in
their cases or an equivalent steel case. In this way any magnetic effects of the enclosure will be ac-
curately duplicated during
testing. A relay may be tested without removing it from the panel by using a
12XLA13A test plug. This plug makes connections only with the relay and does not disturb any shorting
bars in the cases.
Of course, the 12XLA12A test plug may also be used. Although this test plug allows
greater testing flexibility, it also requires C T shorting jumpers and the exercise of greater care since
connections are
made to both the relay and the external circuitry.
6

GEI-12083
All alternating current operated devices are affected by frequency. Since' non-sinusoidal waveforms
can be analyzed as a fundamental frequency plus harmonics of the fundamental frequency, it follows that
alternating current devices (relays) will be affected by the applied waveforms.
Therefore, in order to properly
test alternating current relays it is essential to use a sine wave of
current and/or voltage. The purity of the sine wave (i.e., its freedom from harmonics) cannot be expressed
as a finite number for any particular relay; however, any relay using tuned circuits, R-L or RC networks,
or saturatingelectromagnets (such
as time overcurrent relays) would be especially affected by non-sinus-
oidal
wave forms.
Similarly, relays requiring d-c control
power should be tested using d-c and not full wave rectified
power. Unless the rectified supply is well filtered, many relays will not operate properly due to the
dips in the
rectified power. Zener diodes, for example, can turn off during these dips. As a general
rule
thed-c source should not contain more than 5 percent ripple.
ACCEPTANCE TESTS
When received, the relays should be given a visual inspection to determine if any of the relay parts
have been damaged in shipment.
Check the nameplate for the proper model of the relay and for the proper ratings as ordered on the
requis
iti on.
Check the fingers and shorting bars in the relay and case according to the internal connections
diagram.
Use figure 4 for the 12CAP15A(-)A relay and Figure 5 for the 12CAP15B(-)A relay.
All electrical checks should be performed in the relay's case in a leveled position.
If it becomes necessary to readjust or check the calibration of the relay, refer to the section
on SERVICING.
LOCATION
These relays should be installed in a location that is clean and dry, free from excessive vibration
and well lighted to facilitate inspection and testing.
MOUNTING
These relays should be mounted on a vertical surface by means of mounting studs or screws. One of
the mounting studs or screws should be permanently grounded by a conductor not less than No. 12 B&S gage
copper wire or its equivalent. The outline and panel drilling diagrams are shown in Figure 14.
CONNECTIONS
The internal connection diagrams are shown in Figures 4 and 5. The external connections diagrams
are
shown in Figures 9, 11, 12 and 13.
INSTALLATION TESTS
Upon installing the relay, it is necessary to know (1) that the voltages and currents go to the
proper relay terminals,
and (2) that none of the relay coils is open-circuited.
Item (1) may be checked easily by means of a phase-angle meter. Determination of the angle between
a current and the three voltages and between a voltage and the other two currents gives all the information
necessary
for a complete vector diagram. The vector diagram plus a knowledge of the direction of power
flow will immediately indicate whether or not the connections are correct.
The above test may be made with a wattmeter but the method is somewhat more involved than the phase-
angle meter
test.
7

GEI-12083
Item (2) may be checked by noting that torque is available and in the correct direction upon removal
of two of the three currents. Each of the three current combinations should be tested in turn. When
making these tests, the phase angle of the currents should be considerably different from the angle of
zero torque.
CAUTION: Every circuit in the drawout case has an auxiliary brush; this is the short one in the case
(not
on the cradle) which the connection plug or test plug should engage first. On every current
circuit or other circuit with a shorting bar, make sure these auxiliary brushes are bent high enough
to engage the connection plug or test before the main brushes in the case do, as otherwise the CT
secondary circuit may be opened (where one brush touches the shorting bar) before the circuit is com-
pleted from the plug to the other main brush. See Figure 15.
OPERATION
In analyzing various connections to the Type CAP15A relay, it is convenient to consider the maonet
as a group of eight wattmeter type units acting upon a single rotor, a combination of each coil and an
adjacent coil being assumed to be one element.
Of course, extraneous torques are developed by combinations of coils which are not adjacent. However,
the torque of an adjacent pair of poles is largely relative to that of any other pair. For instance, the
torque produced
by the interaction between coils Band H (part "a," figure 7) is approximately 15 percent
of
that produced by coil combinations A-H, while the torque produced by combination C-H is about two per-
cent, a
negligible amount. The torques of alternate poles (e.g., A-C or B-H) being appreciable, the con-
nections are arranged
so that their torques balance out substantially to zero, a factory adjustment being
provided for
more accurate balance of the current torques. (See CURRENT BIAS ADJUSTMENT). Referring to
the currents in
part "a," Figure 7, it can be seen that the torque produced by the interaction between
coils A and G is balanced by the equal and opposite torque of combination E-G is balanced by that of com-
bination C-E.
Part "a" of Figure 7 shows schematically the currents and voltages applied to the eight coils with
connections
as in Figure 9, connection A. For clarity one current coil and its adjacent potential coils
are isolated in part "b," Figure 7. It is observed that 13 acts with EI-2 and E2-3' the resulting torque
being equivalent to the reaction
of 13 with the vector difference of EI-2 and E2-3 (difference because
the
potential coils are on opposite sides of the current coil). The vector relations are also shown in
part "b." Part "c" and "d" show corresponding coil and vector relations for the other two currents, 12
and II. It is noted (part "e" of Figure 7) that the two remaining coil combinations produce equal and
opposite torques.
Considering a potential coil and its adjacent current coil, this combination would have maximum
torque when the current leads the voltage by 20 degrees. Hith the connections of part "a" of figure 7,
it is seen that 13 will lead EI-2 -E2-3, by 20 degrees when 13 lags its phase-to-neutral voltage by 40
degrees. Thus, with these connections, maximum torque (balanced three-phase conditions) is obtained
when a current lags itsphase-to-neutral voltage by 40 degrees.
ADJUSTMENTS
CUP AND STATOR
These relays are properly adjusted at the factory to obtain the desired characteristic and it is
advisable not to disturb these adjustments. If for any reason it becomes necessary to remove the contact
plate and rotor, the following procedure must be followed:
l.
2.
3.
4.
Remove the cradle from the case.
Remove the two screws holding the top inner block to the cradle and tilt the block up and back
so that it ;s possible to work on the top of the relay.
~isconnect the four leads which go to the contact plate at the terminals in the upper and lower
lnner blocks
and draw the loose ends out through the holes in the mounting plate.
Remove the two screws which secure the top bearing plate.
8

GEI-12083
5. The contact plate is secu~ed to the stator by means of three screws. The screws are located on
the right-hand and left-hand sides in the front and at the middle at the rear. Remove the three
screws.
6. The shaft rotor and top bearing plate will now lift out of the stator as the contact plate is raised.
7. The rotor may be removed from the shaft by loosening the two set screws which fit into V-holes
in the
shaft.
The two stator castings are permanently fastened together with the laminations clamped between them,
and the faces of the poles and the cylindrical surfaces on these castings are then machined true about
the
same axis. To preserve this alignment, the large rivets in the corners should never be removed.
Use care in handling the rotor while it is out of the relay, and see that the air gap and rotor are
kept clean.
In reassembly, the rotor will go into the air gap easily without forcing, if the parts are held in
proper alignment.
The lower-jewel bearing should be screwed all the way in until its head engages the end of the
threaded core.
The upper bearing should be adjusted to allow about 1/64 inch to 1/32 inch end play to
the
shaft.
To check the clearance between the iron core and the inside of the rotor cup, press down on the
contact
arm near the shaft and thus depress the spring-mounted jewel until the cup strikes the iron. The
shaft should move about 1/16 inch.
The lower jewel may be tested for fractures by exploring its surface with a fine needle. If replaced
with a
new jewel a new pivot should be screwed into the end of the shaft at the same time.
ACCEPTANCE TESTS
The contact gap may be adjusted by loosening slightly the same screw at the front of the contact
block as mentioned previously. The screw should be loose enough only to allow the contact barrel to ro-
tate in its sleeve.
The time curves of Figure 1-lA were taken with a contact gap of 0.018 inch. This gap may be obtained
in the following manner:
With the right-hand contact tube or barrel secured in place, turn the left-hand
barrel in the opposite direction approximately 210 degrees or 0.6 revolutions from contact closing.Tighten
the screw
which secures the barrel.
Each moving contact may be removed by loosening the screw which secures it to the contact arm and
sliding it from under the screw head.
HOLDING COILS
The location of each holding coil may be adjusted by loosening the mounting screw and sliding the
coil
either to the left or the right in a groove provided for that purpose. The holding coils are located
in the factory
so that there is a gap of aboutO.055 inch between the pole pieces and the armature. The 0.055
inch is equivalent to 1-5/B turns of the contact barrel.
CONTROL AND LEAD-IN SPRING
The control and lead-in springs are adjusted in the factory to close the right-hand contact when the
relay
is de-energized. The closing spring torque is equivalent to about 45 degrees motion of the spring
adjusting ring located
just under the top bearing plate. The tension of the control spring may be changed
by loosening the hexagonal screw located at the rear of the adjusting-ring to the desired position.
CLUTCH - 12CAP15B(-)A
The clutch adjusting screw should be tightened as much as possible so that the clutch does not slip.
:LUTCH-12CAP15A(-)A
Connect the relay per Figure BA. Apply rated voltage and current to the relay and set the phase angle
9

GEI-12083
meter for 0 degrees. The clutch should slip between 7.5 and 10 amperes. Adjust the screw and locknut
located
on the right side. front view of the moving contact assembly if the clutch slip is not as listed
above. Clutch slip ;s considered acceptable if the cup assembly makes one or more revolutions. This can
be determined by visually noting the movement of the u-shaped pin located at the top of the cup shaft.
MECHANICAL ADJUSTMENTS
SERVICING
12CAPI5A(-)A
The clutch can be checked by connecting the relay per Figure8A. current and voltage. With rated
voltage applied, increase the current until the clutch begins to
slipi this should occur between 7.5 and
10 amperes.
Check the end play which is the upper end play of the cup and movina contact assembly. This should
be between 1/64 inch and 1/32 inch.
The contact gap with the relay de-energized should be 0.016-0.020 inch.
The holding coil gap should be approximately 0.055 inch (±) 0.005 inch.
Co~nect studs 1 and 11 to a variab1ed-csource. Close the left contact and the target should operate
as follows.
Target Rating -
Amps Operatina Current - Or Less
0.20 0.17 amps
1.00 0.85 amps
POLARITY TESTS
Complete polarity tests are made in the factory and these may be checked by connecting terminals A
and C together, connecting terminals Band Dthrough a resistor (20 ohms) and apply rated voltage to ter-
minals C and D. With these connections, the left-hand contact (front view) should close in each of the
following
eight checks:
TABLE II
Current
Coil
I Potential
Coil
A B C , D
3 4 I
19
20
3 4
14
13
4 6 !
17
18
4 6
20
10
7 8
15 16
7 8
18
17
9 10
13
I
14
9 10
I
16 15
I
PHASE ANGLE TESTS
Connect the relay to an external circuit according to that shown in Mgure 8A. With this connection,
the polyphase phase angle of the relay
can be checked. The angle of maximum torque with the 8A connections
should
be 40 degrees lead (~) five degrees. Pickup should be less than 0.025 amperes at rated vo1tao~ and
frequency at the angle of maximum torque.
If a phase shifter, phase-angle meter is not available, the 12CAP15A(-)A can be rechecked or recali-
brated as follows:
(a) Return the control spring to
its neutral (centered between the contacts) by loosening the hex
stud at the top rear of the unit, and turning the control spring adjuster to accomplish the
centering.
10