Embed Size (px)
Citation preview
21/07/2010 1 MRAR 01/96 C
MRAR - Auto Reclosing Relay
SELECT
RESET
VALUE
VALUE
ENTER
TRIP
P&BRSMLMA
In =
Vn =
A
V Fn = 50/60 Hz
V PHVx =
MRARMODEL
SERIAL NO. =
No.SHOT
tD2tf
tD1 tD4
tD3
tC1
tR
MRI-IDS
PB
OLORUNOK I
CB
No M
No L
P&B Engineering P&B Engineering
Belle Vue Works 12-14 Crompton Way
Boundary Street Crawley
Manchester West Sussex
M12 5NG RH10 2QR
Tel: 0161 230 6363 Tel: 01293 524204
Fax: 0161 230 6464 Fax: 01293 534617
21/07/2010 2 MRAR 01/96 C
Contents
Contents
1. Introduction .........................................................................................................................................................................4
2. Application ..........................................................................................................................................................................5
3. Features and characteristics .................................................................................................................................................5
4. Design..................................................................................................................................................................................6
4.1 Circuit Diagram ................................................................................................................................................................6
4.1.1 Information Inputs ..........................................................................................................................................................6
4.1.2 Output Relays .................................................................................................................................................................7
4.2 LED's .................................................................................................................................................................................7
4.2.1 Status LED's ...................................................................................................................................................................8
4.2.2 Adjusting LED's..............................................................................................................................................................8
4.2.3 Remote data communication...........................................................................................................................................8
4.2.4 Push buttons .................................................................................................................................................................10
4.3 Code jumpers...................................................................................................................................................................10
4.3.1 Password programming ...............................................................................................................................................11
4.3.2 Alarm and Trip relay function ......................................................................................................................................11
5. Working Principles ............................................................................................................................................................12
5.1 Status Descriptions ..........................................................................................................................................................12
5.1.1 Inactive .........................................................................................................................................................................12
5.1.2 Reclaim Time ................................................................................................................................................................12
5.1.3 AR Ready ......................................................................................................................................................................12
5.1.4 AR Starting ...................................................................................................................................................................12
5.1.5 AR Cycle .......................................................................................................................................................................12
5.1.5 AR Blocked ...................................................................................................................................................................12
5.2 Description of Status Transition......................................................................................................................................13
5.3 Functional Sequence........................................................................................................................................................14
5.3.1 Switching on the MRAR Relay......................................................................................................................................14
5.3.2 Switching on the Circuit Breaker Manually .................................................................................................................14
5.3.3 Switching off the Circuit Breaker Manually .................................................................................................................14
5.3.4 Starting Auto-Reclosing................................................................................................................................................14
5.3.5 Reclosing Without Success ...........................................................................................................................................14
5.3.6 Successful Reclosing.....................................................................................................................................................15
5.3.7 Repeated Reclosing.......................................................................................................................................................15
5.3.8 External Blocking and Reseting....................................................................................................................................15
5.3.9 Supervision of the Circuit Breaker Ready Information ................................................................................................15
5.4 Operation and Release of the Output Relays...................................................................................................................15
5.5 Blocking and Cancellation of Blocking ...........................................................................................................................16
5.5.1 Blocking........................................................................................................................................................................16
5.5.2 Cancellation of Blocking ..............................................................................................................................................16
5.6 Circuit Example - Connection Diagram of the MRAR and MRI Together ..................................................................17
5.7.1 Two Times AR Programming of the Unit, At Second Attempt Successful.....................................................................18
5.7.2 Two Time Programming of the Unit, Reclosing Unsuccessful. ....................................................................................19
5.7.3 Manual Switching On of the Circuit Breaker to Faulty Lines ......................................................................................19
6. Operation and Adjustment. ................................................................................................................................................20
6.1 Definition of Setting Values .............................................................................................................................................20
6.2 The AR Counter ...............................................................................................................................................................20
7. Testing ...............................................................................................................................................................................21
7.1 Power On.........................................................................................................................................................................21
7.2 Output Relay Tests...........................................................................................................................................................21
7.3 Checking the Set Values ..................................................................................................................................................21
7.4 Checking the CB Status Input Circuit (28-15).................................................................................................................21
7.5 Checking the External Block Input Circuit (24-15).........................................................................................................21
7.6 Checking the External Reset Input Circuit (25-15) .........................................................................................................21
8. Technical Data...................................................................................................................................................................22
8.1 Input Circuits...................................................................................................................................................................22
8.2 Output Relays ..................................................................................................................................................................22
8.3 Setting Ranges and Steps.................................................................................................................................................22
21/07/2010 3 MRAR 01/96 C
8.4 System data......................................................................................................................................................................23
8.5 Power supply ...................................................................................................................................................................24
9 Housing ..............................................................................................................................................................................25
9.1 Connection Details ..........................................................................................................................................................26
10. Order Form ......................................................................................................................................................................27
21/07/2010 4 MRAR 01/96 C
1. Introduction
The application of powerful microprocessors opens a new chapter for power system protective relaying.
The digital processing of measured values and the ability to perform complex arithmetic and logic
operations, give digital protection relays significant performance and flexibility improvements over their
traditional analogue counterparts. Additional advantages - very small power consumption, adaptability,
self-supervision, fault diagnosis through fault data recording, smaller physical construction and
selectable relay characteristics - all combine to allow the implementation of accurate and highly reliable
protection schemes at a significantly reduced financial burden.
The development of microprocessor based protective relays and their introduction into the market has
been stimulated by the recent trend to replace analogue with digital equipment. This modern trend has
prompted the development of a new P&B protective relay family - the MR relay series. This
comprehensive family of protection relays can satisfy the demands of even the most complex protection
schemes:
MRI - Overcurrent Relay (Independent time/I.D.M.T + earth + directional facilities)
MRI-V - Voltage Dependent Overcurrent Relay
MREF - Restricted Earth Fault Relay
MRAR - Auto-Reclosing Relay
MRMF - Mains Failure Relay
MRVT - Voltage Protection
MRFT - Frequency Protection
MROS - Vector Surge or Rate of Change of Frequency
MRNS - Negative Sequence Relay
MRRP - Power Relay
MRCS - Check Synchronising Relay
MRFF - Field Failure Relay
MRDG - Differential Relay
The superiority of digital protective relaying over traditional analogue devices, as embodied by the MR
relay family, is summarised by the following features:
•••• Integration of many protective functions in a single compact case
•••• High accuracy owing to digital processing
•••• Digital relay setting with very wide setting ranges and fine setting steps
•••• Comfortable setting procedure through extensive human - relay dialogue
•••• Measured values and fault data indication by means of alpha-numeric display
•••• Data exchange with DCS/SCADA by means of RS485
•••• Operational reliability through self-supervision
A similar but simplified range, with reduced functions and without display, is also available. The MIRI
- overcurrent and earth fault relays, and the MIRV - undervoltage, overvoltage and neutral voltage
displacement relays. To complement the MR series, a range of Auxiliary, Timing and Tripping devices
are also available.
21/07/2010 5 MRAR 01/96 C
2. Application
In transmission line networks about 70% of the occuring failures are transient; arcing, tree branches on
power lines etc. With the use of auto-reclosing techniques it is possible to "switch off" the supply until
these faults have been removed. Without utilzing auto-reclosing techniques, consumer interuptions
occur frequently which is unfortunate especially as the vast majority of faults have been removed a short
time after the initial outage.
The MRAR digital auto-closing relay is a universal device suitable for a number of reclosing schemes.
A very wide range of applications may be encompassed when the MRAR is combined with other relays
from the MR range (eg. the MRI-I & MRCS).
The protective functions of the MRAR are summarised as follows:
• Independent adjustable time ranges.
• Four digit counter for display of the completed auto-reclosing.
• High-Set blocking output available
• External blocking and release.
• Suitable for use with a number of IDMT devices.
• Maintenance Alarm and Lock-out.
• Suitable for generator and similar applications requiring a check-sync function.
3. Features and characteristics
• Complete digital processing of all logic inputs
• Extremely wide setting ranges with fine setting steps
• Unauthorised user access control through password protection
• User defined password
• Continuous self-supervision of software and hardware
• Outstanding design flexibility for easy selection of appropriate operational scheme for
numerous applications
• Serial data communication facilities via RS485
• Wide voltage range for DC or AC power supply
• Withdrawable modules
21/07/2010 6 MRAR 01/96 C
4. Design 4.1 Circuit Diagram
28
27
21
22
23
24
25
26
15Supply
Reserve
External Reset
External Block
Sync. Check
CB Energy
Start Protection
Trip Protection
CB Status
SupplyPOWER
SUPPLY
1 2 CASE
Supply
MRAR
54 5553External Reset Blocking Input
L N L
CLOSE CB33
31
29
32
3034
4852
50
45
43
41
44
4246
40
38
36
37
3539
+
7 9 10
Gnd-
4751
49
SELF SUPERVISION
AR BLOCKED
AR IN PROGRESS
HIGH SET BLOCK
RS485
Note: Terminals 1 and 2, and inputs 21 - 28 and 15 are not to be tested by the application of a high
voltage power frequency input ("flash tested"), as this will cause damage to the unit.
Explanation of the Circuit Diagram
4.1.1 Information Inputs
Using the information inputs the MRAR relay decides whether and when auto-reclosing will take place.
Circuit Breaker Status (28)
With input terminal 28, the position of the circuit breaker can be supervised. When the circuit breaker is
closed, mains supply uninterrupted, the auxiliary voltage is connected to terminal 28.
Protection Energised (21)
When protection is energised, e.g. from over current time protection, a fault timer is started. The MRAR
relay changes from a "Ready" status to a "Starting" status. (see also para 4.3.4).
21/07/2010 7 MRAR 01/96 C
Protection Trip (27)
When a tripping command occurs from the protection before the fault timer has expired, the unit
changes from the "Starting" status to the "Cycle" status switching the circuit breaker to off. (see also
para 4.3.4).
Circuit Breaker Energy (22)
Because the circuit breaker needs a certain time between two reclosings in order to trip again, the ready
signal of the circuit breaker; auxiliary voltage at terminal 22; is checked before a new reclosing can take
place. (see also para 4.3.9).
Synchronism Check (23)
In order to prevent a reclosing of the unit at an asynchronous phase position, input 23 is connected to a
synchronising unit. If no synchronous control is necessary, the auxiliary voltage is applied to terminal
23.
External Blocking (24) and External Reset (25)
The unit is blocked when applying voltage to terminal 24. This blocking can only be removed by
applying the auxiliary volatge to terminal 25. Blocking has priority during the simultaneous activation
of inputs 24 and 25.
Reserve (26)
This input is not used at this time.
Common Point (15)
All the listed inputs have the common point connection L- or N.
4.1.2 Output Relays
The MRAR has 5 output relays. One relay with two change-over contacts for tripping and other four
with a single change-over contact are used for siginalling:
•••• Switch on command to the circuit breaker (31, 29, 33, 32, 30, 34)
•••• Blocking of the high set trip (38, 36, 40)
•••• Signal "AR in Progress" (43, 41, 45)
•••• Signal "AR Blocked" (47, 49, 51)
•••• Signal "Self-supervision" (50, 48, 52)
4.2 LED's
The front panel consists of five push buttons for control and adjustment and twenty LED's for
indication. The LED's on the left hand side next to the display indicate the status, error messages and
AR results. The LED's on the left under the status LED's are provided for adjustments, their functions
are shown by the legend next to the LED.
21/07/2010 8 MRAR 01/96 C
Front Panel
SELECT
RESET
VALUE
VALUE
ENTER
TRIP
P&BRSMLMA
In =
Vn =
A
V Fn = 50/60 Hz
V PHVx =
MRARMODEL
SERIAL NO. =
No.SHOT
tD2tf
tD1 tD4
tD3
tC1
tR
MRI-IDS
PB
OLORUNOK I
CB
No M
No L
4.2.1 Status LED's
OK - Green, Unit ready for operation;
extinguished unit inactive.
RUN - Red, AR in progress
LO - Green, AR Locked Out
O→I - Green, AR successful; Red, AR
Unsuccessful
CB - Red, Circuit Breaker Fault
MA - Yellow, Maintenance Alarm
ML - Yellow, Maintenance Lockout
RS - Yellow, Remote Data
Transmission
4.2.2 Adjusting LED's
SHOT - Green, Number of reclosing attempts
No- Red, Number of AR's carried out
tf - Green, Fault Time
tD1 - Green, Dead Time for the first reclosing
tD2 - Red, Dead Time for the second reclosing
tD3 - Green, Dead Time for the third reclosing
tD4 - Red, Dead Time for the fourth reclosing
tC1 - Green, Close Impulse Time
tr - Green, Reclaim Time
No→M- Green, Number of reclosing attempts until Maintenance Alarm
No→L - Green, Number of reclosing attempts until Maintenance Lockout
4.2.3 Remote data communication
As an option, the MRAR may have an RS485 interface for remote data communication with a control
centre. The unit provides the following information:
• Status signals
• Relay settings
• Self supervision alarm signal
21/07/2010 9 MRAR 01/96 C
Table: Adjustment Possibilities by Means of the Display
Function Display Shows Push button Illuminated LED
Normal Operation P&B
Program Version Version Number <TRIP> x 2
Password Inquire PSW? <ENTER> <TRIP>
Wrong Password NO!
Save Parameter SAV? <ENTER>
Saved Parameter SAV! <ENTER>
Test Output Relays TRI? <TRIP>
Relay Trip Testing TRIP <TRIP>
End of Trip Test END!
Reclosing Successful Clos O→I Green
Reclosing Unsuccessful Open O→I Red
No CB On signal after a
switch ON
CB!! O→I Red, CB Red
LO Red
No CB Off signal after
protection OFF
CB?? CB Red
Dead Time closing conditions
not met
S/E? O→I Red
Switch was manually
switched off during Reclaim
Time
Manu
Password **** combination of
<SELECT>,
<∧>,<∨>,
<ENTER>
Number of AR Attempts 0 to 4 <SELECT>,
<∧>,<∨>
SHOT Green
Fault Time, tf Time in seconds <SELECT>,
<∧>,<∨>
tf Green
Dead Time for AR Ateempts
tD1 to tD4
Time in seconds <SELECT>,
<∧>,<∨>
tD1 - tD4 Green/Red
Close Impulse Time, tC1 Time in seconds <SELECT>,
<∧>,<∨>
tC1 Green
Reclaim Time, tr Time in seconds <SELECT>,
<∧>,<∨>
tr Green
AR attempts until
Maintenance Alarm, No→M
1 to 200 <SELECT>,
<∧>,<∨>
No→M Green
AR attempts until
Maintenance Lockout, No→L
1 to 200 <SELECT>,
<∧>,<∨>
No→L Green
Number of carried out AR
attempts
1 to 200 <SELECT>,
<∧>,<∨>
No Red
21/07/2010 10 MRAR 01/96 C
4.2.4 Push buttons
The front panel contains five push buttons used for setting, measuring and other user functions.
The individual setting and measuring values can be selected in turn by pressing the <SELECT> /
<RESET> push button. This button also resets the relay if pressed for approximately 3 seconds.
The <UP> and <DOWN> push buttons are for incrementing and decrementing any selected parameter.
Continuous pressing of these push buttons will cause the parameter to change at an increased rate.
The <ENTER> push button is used to transfer the indicated value to the internal parameter memory. An
unintended or unauthorised change of the selected parameter can be avoided through the password
protection facility.
The <TRIP> push button is used to test the output relay circuits, both for tripping and signalling. This
operation is also password protected.
4.3 Code jumpers
Behind the front panel of the MRAR are three code jumpers used to preset the following functions:
•••• Password programming
•••• Alarm and Trip relay functions
The following figure shows the position and designation of the code jumpers
J3 J2 J1
Code Jumper ON
Code Jumper OFF
Front Board
Code Jumper
21/07/2010 11 MRAR 01/96 C
4.3.1 Password programming
The MRAR relay is normally delivered with the preset password "∧∧∧∧", it can be reprogrammed
using the removable code jumper J1. After power on and the pressing of any push button, the MRNS
relay enquires for a new password with the text <PSW?> appearing on the display. A new password is
then entered by pressing a combination of <SELECT>, <UP>, <DOWN> or <ENTER>, as chosen by
the user. After the new password has been given, the relay module is extracted from its case and code
jumper J1 removed.
4.3.2 Alarm and Trip relay function
The following functions of the MRAR alarm relays may be preset using jumpers J1 & J2:
•••• Alarm relay activation upon initiation or after a trip
•••• Manual or Automatic reset of the output relays
Code jumper J2 - OFF
The alarm relays respond directly upon the initiation of the corresponding measuring circuit. Thus,
an alarm signal, e.g. for negative sequence current, will be given before the relay trips.
Code jumper J2 - ON
The alarm relay responds only after the relay has tripped. Thus, the alarm relay and the trip relay
respond at the same time.
Code jumper J3 - OFF
All output relays will be reset automatically after tripping, once the fault has been cleared.
Code jumper J3 - ON
All output relays remain activated and must be reset manually by pressing the <RESET> push
button, after the fault has been cleared.
Summarising the coding possibilities
Code jumper Function Code jumper Position Operation Mode
J1 Password OFF
ON
Normal position
Password programming
J2 Fast Trip OFF
ON
Fast Trip before the First
Reclose
Fast Trip after last
Reclose.
J3 Reset OFF
ON
Output relays will be reset
automatically.
Output relays will be reset
manually.
21/07/2010 12 MRAR 01/96 C
5. Working Principles
5.1 Status Descriptions
For the illustration of the functional sequence the MRAR defines six conditions:
5.1.1 Inactive
The relay is in the inactive state when the following conditions are fulfilled:
• The circuit breaker is in the OFF position
• The unit is not in the blocked state
• The unit is not in the "Starting/Cycle" state.
Activation of the unit due to protection faults is not possible in the inactive state, thus there can be no
automatic reclosing.
5.1.2 Reclaim Time
The relay is in the Reclaim Time State when the Reclaim Time:
• Has not yet expired
• Has not been interrupted by other faults
Activation of the unit due to protection faults is also not possible in the Reclaim Time State, thus no
auto reclosing can take place.
5.1.3 AR Ready
The relay is in the AR Ready State when the following conditions are met:
• The Circuit Breaker is in the ON position
• The Reclaim Time has expired
• The unit is not in the blocked state
• The unit is not in the "Starting/Cycle" state.
Only in the AR Ready State is any action due to protection faults able to take place.
5.1.4 AR Starting
In the AR Starting state the start conditions for automatic reclosing, by means of the protection
commands, and the circuit breaker are checked.
5.1.5 AR Cycle
The starting commands are carred out in the AR Cycle state and the results, AR Successful or AR
Unsuccessful, are evaluated accordingly.
21/07/2010 13 MRAR 01/96 C
5.1.5 AR Blocked
The AR Unit changes immediately to the AR Blocked state when an external or internal blocking signal
exists. No auto reclosing is possible in this state and only an external reset signal can cancel this. An
exception to this is the blocked state that is reached when the unit reaches the preset Maintenance
Lockout number. This blocked state can be cancelled when the counter (No) has been reset. (see also
para 5.2).
5.2 Description of Status Transition
AR Status Matrix
Closed
From
Inactive Reclaim
Time
Ready Starting Cycle Blocked
Inactive CB
Manual
ON
External
Blocking
Signal
Reclaim
Time
CB OFF Reclaim
Time
Exprired
External
Blocking
Signal
Ready CB OFF Protection
Running
and/or
Tripped,
CB Energy
OK
External
Blocking
Signal
Starting Starting
Conditions
Not
Fulfilled
Start
Signal
Interrupted
Start
Conditions
Fulfilled
(Fault
Time, CB
OFF etc.)
External
Blocking
Signal
Cycle AR
Successful
External or
Internal
Blocking
Signal
Blocked External
Blocking
Signal
= No Transition Possible
From the above table it is possible to determine which status transitions are possible with the MRAR.
When the unit for instance is in the Cycle State, only two transitions are possible:
• Transition to the Ready state when reclosing has been successful.
• Transition to the Blocked state by an external or internal blocking signal.
The grey shaded sections indicate that no transition is possible.
21/07/2010 14 MRAR 01/96 C
5.3 Functional Sequence
To understand this chapter completely it is advised that paragraphs 4.1 and 4.2 should be read first.
5.3.1 Switching on the MRAR Relay
If the circuit breaker to be supervised is in the off position while switching on the MRAR, the unit
changes to the Inactive state when applying the auxiliary voltage. The OK LED on the front panel is not
lit and the unit is not ready for auto reclosing. If, however, the circuit breaker is in the on position when
applying the auxiliary voltage, the unit changes to the Reclaim Time state and remains blocked for this
period (from 1 to 300 seconds adjustable). This is indicated by the tr LED. After the Reclaim Time has
elapsed the unit changes to the Ready state and auto reclosing may now be carried out. The OK LED
indicates this state.
5.3.2 Switching on the Circuit Breaker Manually
If the circuit breaker is switched manually to an un-faulted line, first the unit will remain blocked for the
Reclaim Time (adjustable 1 - 300 seconds) and then changes to the Ready state. If the circuit breaker is
switched manually to a faulted line then the breaker is switched off by the associated protection unit.
The MRAR then remains in the Inactive state and reclosing is not possible.
5.3.3 Switching off the Circuit Breaker Manually
When switching off the circuit breaker manually, the unit changes at once from the Ready state to the
Inactive state. The OK LED extinguishes and reclosing is not possible.
5.3.4 Starting Auto-Reclosing
When signals are applied to the Protection Energising or the Protection Tripping inputs, 21 and 27, the
unit changes from the Ready to the Starting state. The RUN LED illuminates and the fault timer (tf
adjustable from 0.01 to 2.05 s) begins to time out. A tripping timer (set at 0.2 s) is started when the
mains protection tripping command takes place before the fault timer has timed out. The "Start
requirements not fulfilled" is evaluated and the MRAR is locked out for the duration of the Reclaim
Time if there is a difference between the Mains Protection Energised/Tripped and the set Fault Time. If
the Circuit Breaker OFF signal occurs before the tripping timer has timed out, it is evaluated as a "Start
Condition Fulfilled" and the unit changes to the Cycle state. If, however, the OFF signal does not occur
before the tripping timer has timed out, it will be evaluated as "Start Condition Not Fulfilled" and the
unit is locked out for the duration of the set Reclaim Time.
5.3.5 Reclosing Without Success
After the start condition has been fulfilled the unit changes to the Cycle state and the Dead Time, tD, is
started. The MRAR can be programmed to reclose between one and four times and for each reclosing a
Dead Time has to be set, (tD1 = 0.1 - 20 s, tD2 - tD4 = 0.2 - 99.9 s). When the Dead Time has expired
and all other reclosing conditions have been fulfilled, the switch on command is given to the Circuit
Breaker. The switch on command will remain as long as the On signal to the Circuit Breaker or the
setting of the On Impulse Timer (adjustable between 0.05 - 9.99 s). With the beginning of the switch on
command the Reclaim Timer is started. When a new OFF signal, not a fault signal, to the circuit breaker
appears during the Reclaim Time, a reclosing has taken place without success. The unit then changes
from the Cycle state to the Blocked state and the RUN LED extinguishes with the LO and O→I LED's
being illuminated.
21/07/2010 15 MRAR 01/96 C
5.3.6 Successful Reclosing
If there is no OFF signal to the circuit breaker and no protection tripping signal within the Reclaim Time
then a successful reclosing has taken place. The unit now changes from the Cycle state to the Ready
state and the O→I LED indicates green signalling a successful reclosing. The LED display can be reset
by pressing and holding the <SELECT/RESET> button for 5 seconds.
5.3.7 Repeated Reclosing
If the MRAR is programmed for more than single shot reclosing a second Dead Time is started after a
new OFF signal to the circuit breaker. After this period a new switch on command follows.
5.3.8 External Blocking and Reseting
The unit is blocked from further reclosing attempts when an external blocking signal is applied to
terminal 24. This is independant of whatever state the MRAR is in at the time. This blocking signal can
only be revoked by the applying of a reset signal to terminal 25.
5.3.9 Supervision of the Circuit Breaker Ready Information
Because the supervision of the circuit breaker energy store responds often after the first fast switch off
(see para. 4.1.1), the signal, AR Not Ready, is not evaluated after a reclosing. The readiness of the
switch is checked before an auto-reclosing and then after the first unsuccessful attempt of auto-reclosing
thereafter. There will be reclosing when the circuit breaker indicates readiness before the beginning of
the switching cycle.
5.4 Operation and Release of the Output Relays
Close Circuit Breaker Relay (31, 29, 33 and 32, 30, 34)
Operation: At the end of the Dead Time (tD) when all closing conditions are fulfilled.
Release: When the circuit breaker is switched on or when the closing Impulse Time (tC)
has expired.
High Set Blocking Relay (38, 36, 40 and 37,35,39)
Operation: When the unit is in the Ready State.
Release: Simultaneously with the first reclosing command.
Alarm AR in Progress Relay (43, 41, 45 and 44,42,46)
Operation: When the MRAR is started.
Release: When all AR cycles are terminated.
21/07/2010 16 MRAR 01/96 C
Alarm AR Blocked Relay (49, 47, 51)
Operation: When a blocking condition is present.
Release: When the blocking signal has been cancelled.
Self Supervision Alarm Relay (50, 48, 52)
Operation: A system hardware/software error.
Release: When fault has been removed.
5.5 Blocking and Cancellation of Blocking
5.5.1 Blocking
The AR Relay is blocked under the following conditions:
•••• A circuit breaker defect was detected during reclosing.
• The external blocking input was activated.
• The AR cycle was terminated without success.
• The circuit breaker energy is not sufficient during a switch on attempt (after first attempt) see also
paragraph 5.3.9.
• The synchronous condition does not exist (can be discounted if auxiliary supply connected to
terminal 23)
• The preset number of reclosings for the maintenance lockout has been reached.
• When the reclosing shot is set to zero, the MRAR can also be blocked at site.
5.5.2 Cancellation of Blocking
The maintenance lockout is cancelled by resetting the AR value (No) to zero. All other blocking inputs
can only be cancelled through the external reset input, terminal 25.
21/07/2010 17 MRAR 01/96 C
5.6 Circuit Example - Connection Diagram of the MRAR and MRI Together
21/07/2010 18 MRAR 01/96 C
Chronological Sequence Diagram of the MRAR
Ready
Inactive
Reclaim Time
Starting
Cycle
Blocked
5.7.1 Two Times AR Programming of the Unit, At Second Attempt Successful
Protection Energised
tD1 tD2
tR
Short Circuit
Protection Tripped
Circuit Breaker
Switch on Command
tD1 = Dead Time 1
tD1 = Dead Time 2
tR = Reclaim Time
As a short circuit occurs the circuit breaker is switched off by the protecting device and the dead time
counter in the MRAR starts to time out. After this dead time, tD1, has elapsed the MRAR gives the
reclosing command to the circuit breaker. If the fault still exists then the breaker will be tripped again by
the protection device and the above mentioned procedure is repeated until the fault is removed or the
number of set shots is reached, in the above case two.
21/07/2010 19 MRAR 01/96 C
5.7.2 Two Time Programming of the Unit, Reclosing Unsuccessful.
Protection Energised
tD1 tD2
Short Circuit
Protection Tripped
Circuit Breaker
Switch on Command
tD1 = Dead Time 1
tD1 = Dead Time 2
Here the chronological sequence is as described in paragraph 5.7.1. The second reclosing shot is
however unsuccessful and thus the unit is blocked.
5.7.3 Manual Switching On of the Circuit Breaker to Faulty Lines
Protection Energised
Short Circuit
Protection Tripped
Circuit Breaker
Switch on Command
1 = Manual On
2 = Protection Tripped
1 2
The MRAR is in the inactive state when the circuit breaker is switched off. When the circuit breaker is
manually switched on, the reclaim time is started. Should there be a fault on the line during the switch
on procedure, the circuit breaker is switched off again via the protection device and the reclaim time is
stopped. The MRAR then changes back to the inactive state.
21/07/2010 20 MRAR 01/96 C
6. Operation and Adjustment.
6.1 Definition of Setting Values
Number of AR Shots
Indicates how often the circuit breaker may be switched on again when a fault occurs.
Fault Time (tF)
Reclosing is permitted during this time. It starts with the tripping of the respective protection device. A
reclosing attempt follows only when the command time of the protective device is shorter than the fault
time set at the MRAR.
Dead Time (tD)
Starts with the off signal of the circuit breaker. No switch on command to the circuit breaker can be
given until this time has elapsed.
Close Impulse Time (tC1)
During the Close Impulse Time, the switch on contact of the MRAR is closed. It starts with the timing
out of the dead time but can be interrupted if the switch on feed back from the circuit breaker exists
before the dead time has elapsed.
Reclaim Time (tR)
This is the time during which a subsequent reclosing is prevented. If the number of the set shots is
reached the MRAR is blocked after the last reclosing attempt. The reclaim time is started during the
switch on command and an off command during the reclaim time leads to the switching off of the
breaker.
Number of Reclosings Until Maintenance Alarm (No.→→→→M)
After a certain number of reclosings the circuit breaker must be serviced. This can be supervised by two
counters in the MRAR. The first counter , No.→M, must be set to a somewhat smaller value then the
lockout and is used as an alarm. If the maintenance lockout has almost been reached the MA
(Maintenance Alarm) LED lights up yellow.
Number of Reclosings Until Maintenance Lockout (No.→→→→L)
When the second counter has passed the preset value, the MRAR is blocked for the purpose of
maintenance. The ML LED is illuminated yellow and the blocking can be reset by setting back the
counter number (see paragraph 5.5.2).
6.2 The AR Counter
The MRAR is equipped with a software counter and the reclosing commands given by the unit are
registered with this counter. After each reclosing command the counter is automatically incremented and
the previous number of AR's carried out can be displayed by pressing the <SELECT/RESET> push
button. The No. LED lights up at the same time. This counter can be reset using the normal setting
procedure detailed previously. During loss of the auxiliary supply the number of reclosings taken place
is stored guranteeing that preset maintenance levels are kept.
21/07/2010 21 MRAR 01/96 C
7. Testing
Please note that these tests are not intended to give detailed information of the type tests carried out on
the MRAR but are function tests only.
7.1 Power On
Switch on the auxiliary supply to the unit, terminals 1 and 2, and check that the message "P&B" appears
on the display and that the self supervision alarm relay is energised, terminals 49 and 51 are closed.
7.2 Output Relay Tests
Press the <TRIP> push button until the display shows the message "PSW?". Enter the correct password
and the message "TRI?" will appear on the display. Press <TRIP> again and all the output relays,
except CB Close terminals 31-33 and 32-34, will close one after the other at one second intervals. Press
the <SELECT/RESET> push button and the relays will return to their original state. Please note, prior to
commencing this test, it is advisable to block the output circuits to avoid unnecessary tripping of the
circuit breaker.
7.3 Checking the Set Values
By repeatedly pressing the <SELECT> push button, you can check all the unit set values. Modification
is via the <UP> and <DOWN> push buttons followed by <ENTER>.
7.4 Checking the CB Status Input Circuit (28-15)
Apply auxiliary voltage to terminals 28 and 15, the red tR LED, Reclaim Time, should illuminate. After
the preset time delay, the LED is extinguished and the green OK LED is lit which indicates the unit is
ready for an auto-reclosing. The High Set Block output relay, terminals 38 and 40 closed, is energised.
7.5 Checking the External Block Input Circuit (24-15)
Apply auxiliary voltage to terminals 24 and 15, the green OK LED should be extinguished immediately
and the red LO LED is illuminated to show that the unit is blocked. The High Set Block output relay,
terminals 38 and 40 open, is de-energised.
7.6 Checking the External Reset Input Circuit (25-15)
Disconnect the auxiliary voltage from terminals 24 and 15 and reapply to terminals 25 and 15. The red
LO LED should extinguish and the Reclaim Time, tR, LED should light; remaining lit until the preset
reclaim time has elapsed. The green OK LED will then be illuminated and the High Set Block output
relay will be energised. The unit is now ready for auto-reclosing.
21/07/2010 22 MRAR 01/96 C
8. Technical Data
MRAR - Auto Reclosing Relay
8.1 Input Circuits
Circuit Opto-electronic Coupler - Isolated inputs (N/O Current circuit)
Inputs Circuit Breaker Status (28-15)
Trip Protection (27-15)
Start Protection (21-15)
Circuit Breaker Energy (22-15)
Synchronous Check (23-15)
External Block (24-15)
External Reset (25-15)
Reserved (26-15)
Input Voltage Same as Auxiliary Supply
Power Consumption 1W for each input
8.2 Output Relays
Number 5
Contacts 2 Voltage free changeover contacts for switch on relays
1 Voltage free change over contact for other relays
8.3 Setting Ranges and Steps
Setting Parameter Setting Range Steps Tolerance
Number of Shots 1 - 4, Blocked 1
Fault Time, tF 0.01 - 2.0 s 0.01 s 3% or 10mS
Dead Time, tD1 0.1 - 20 s 0.1 s 3% or 10mS
Dead Time, tD2 0.2 - 99.9 s 0.1 s 3% or 10mS
Dead Time, tD3 0.2 - 99.9 s 0.1 s 3% or 10mS
Dead Time, tD4 0.2 - 99.9 s 0.1 s 3% or 10mS
Close Time, tC1 0.05 - 9.99 s 0.01 s 3% or 10mS
Reclaim Time, tR 1.0 - 300 s 1.0 s 3% or 10mS
AR's until Maintenance Alarm, No.→M 1 - 200 1
AR's until Maintenance Lockout No.→
L
1 - 200 1
21/07/2010 23 MRAR 01/96 C
Fixed Parameter Value Tolerance Remarks
Tripping Time 200mS < 10mS This time starts with the protection
tripping command and is interrupted by
the CB Off Alarm. When this time has
elapsed, a CB defect is present.
Energy Wait Time 200mS <10mS During this time the CB's Standby state
is checked before reclosing. This check
can be blocked by applying auxiliary
voltage to terminal 22.
Sync. Wait Time 200mS < 10mS During this time the synchronous
condition is checked before reclosing.
This check can be blocked by applying
auxiliary voltage to terminal 23.
Protection Wait
Time
200mS < 10mS This time starts with the protection
tripping command after reclosing and is
interrupted by the CB Off Alarm.
C.B. Wait Time 100mS < 10mS This time starts with the CB Off Alarm
after an unsuccessful reclosing and is
interrupted by the Off Command. When
this time has elapsed a manual Off is
present.
Relay Test Time 1 s < 10mS With a time gap of one second between
each relay, this feature checks the
tripping of each of the output relays.
Default Password ^^^^ Can be re-programmed using code
jumper J1, see paragraph 4.3.
8.4 System data
Design standard = IEC 255-4
Operating temperature range = -20°C to 70°C
Storage temperature range = -40°C to 85°C
Relative humidity = 93% @ 40°C for 56 days
Test Voltages to EN50081-1, EN50082-2
Isolation Test = 2.5kV / 50Hz / 1 min.
Impulse Test = 5kV, 1.2 / 50mS, 0.5J
High frequency interference Test = 2.5kV / 1MHz
Burst transient Test = 4kV / 2.5KHz, 15mS
ESD Test = 8kV
21/07/2010 24 MRAR 01/96 C
RFI Suppression Test = 10V/m, 27 - 500MHz, 1 Octave/ 3 min.
EMI Suppression Test = 10V/m
Mechanical Tests:
Shock = IEC 41B (CO) 38, Class 1
Vibration = IEC 41B (CO) 35, Class 1
Degree of Protection = Front - IP52
Rear - IP00
Weight = Approx. 2kg.
8.5 Power supply
Two auxiliary power supply versions are available:
Vaux = 24V in a range from 16V to 60V AC
or in a range from 16V to 80V DC
Vaux = 110V in a range from 50V to 270V AC
or in a range from 70V to 360V DC
21/07/2010 25 MRAR 01/96 C
9 Housing
Throughout the MR series range a modular housing system has been employed, utilising the latest high
quality UK manufactured industry standard case components. This approach affords maximum
flexibility for both the relay scheme designer and the maintenance engineer. The relay modules are fully
withdrawable for ease of maintenance and where applicable incorporate automatic short-circuiting CT
connections to avoid dangerous open circuit CT overvoltages. A clear plastic front cover is provided for
inspection purposes.
MRAR units are supplied in standard height (179mm≅7in.) cases, complying with IEC 297 size 4U.
The rigid case wall is manufactured from a single sheet of hot dipped galvanised steel coated externally
with Plastisol PVC and internally with a low gloss alkyd paint finish. This construction technique
provides improved thermal transfer characteristics over plastic walled cases and combines exceptional
corrosion and flame resilience with good electromagnetic and electrostatic screening properties allowing
many relays to be freely situated in close proximity and hazardous environments. When the relay is
inserted a leaf spring along the top edge of the module makes contact with a solidly bonded nickel
plated steel strip on the interior of the case, providing excellent earth continuity. This strip is brought out
at the rear of the case, above the terminal block, where it forms a separate earthing terminal. A rigid
front mounting flange is provided allowing the entire range of standard cases to be flush mounted
without alteration. These flanges are also used to mount the relay inspection cover which is secured by
thumbscrews. Securely bonded channels can be provided on the top and bottom surfaces toward the rear
of the case allowing large rigid assemblies to be created by the use of joining strips located in these
channels.
This uniform but highly flexible housing system integrates excellent mechanical strength with good
electrical practice in industry standard sizes.
PANEL CUT OUT FLUSH
MOUNTING FIXING DETAILS
4 HOLES 4.4mm DIAMETER
99
168 159
52 23.5
10
97
45
PUSH BUTTON
PROJECTION 10mm
NOT SHOWN TO SCALE
103
177
212
Clearance
25 min
157
32
OPTIONAL
OPTIONAL
OPTIONAL
Min28
NOTE Minimum gap between vertical
spacing is required in order to
withdraw relay from the case above.
178
Required to open case SIZE 100 CASE
21/07/2010 26 MRAR 01/96 C
9.1 Connection Details
The rear terminal block accepts both pre-insulated screw and push-on blade type connectors which may
be used singly or in combination. Each terminal has 1 screw type and 2 blade type connectors.
Screw: Each connection uses a 4mm (M4) screw outlet and accepts standard L-
shaped ring type connectors designed for 4mm screws.
Blade: Each connection facilitates 2 pre-insulated push-on blades 4.8mm wide
0.8mm thick complying with BS5057.
Combinations: Each terminal will accept either;
2 ring type connectors
or 2 push-on blade type connectors
or 1 ring type connector & 1 push-on blade type connector
1
3
5
7
9
11
13
15
17
19
21
23
25
27
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Earth
Rear terminal block connections.
Each terminal
1 screw &
2 spade29
31
33
35
37
39
41
43
45
47
49
51
53
55
30
32
34
36
38
40
42
44
46
48
50
52
54
56
All information subject to change without notice
Publication number MRAR 01/96 C
21/07/2010 27 MRAR 01/96 C
10. Order Form
Auto Reclose Relay
MIRD --
AD
Housing 19" RackFlush mounting
QUANTITY
* Aux Voltage 24 V
110 V
L
H
Rated current 1
5
1A
5A
Non-standard voltages
available on request
* Range 16-60V ac, 16-80Vdc for 24V device
50-270V ac, 70-360Vdc for 110V device
T
Transformer T
SAT option SAT
Dyn1Winding Vector group of transformerfor example Dyn11,Dd0, etc
L.T. C.T. CT Ratio LV side for example 3000/5A
Rating Transformer maximum ratingfor example 2MVA
H.T. C.T. CT Ratio HV side for example 150/5A
150/5
H.T Flc Full load current HV side/ or rated voltagefor example 105A
105A
3000/5
L.T Flc Full load current LV side/ or rated voltagefor example 2667A
2667A
2MVA
SAT
* Aux Voltage 24v AC/DC
110V AC/DC
Data Communications, RS485
Housing 19" Rack
Flush mounting
MRAR
* Non-standard voltages
available on requestA
D
R
L
H
PBSI Ltd Trading as
P&B ENGINEERING
Bell Vue Works,
Boundary Street,
Manchester. Tel: 0161-230-6363
M12 5NG. Tel: 0161-230-6464
