WIM1-H - Time Overcurrent Relay with Multi-Characteristic
Contents
1 General
2 Characteristics and Features
3 Working Principle
3.1 Tripping Outputs
3.1.1 Adaptation of Current Transformer and
Tripping Device
3.1.2 Limiting of the Relay Short Circuit
Measuring Currents
3.1.3 Average Value Correction
3.2 Setting of the relay
3.2.1 Setting of the switches
3.2.2 Settings at the CHAR - switch
3.3 Overcurrent tripping
3.4 Fast short-circuit tripping
3.5 Integrated safety routine
3.6 Setting example
3.7 Remote tripping
3.8 Overcurrent - short-circuit indications
3.8.1 Tripping indication by means of
flag indicator
4 Relay testing and commissioning
4.1 Checking the set values
4.2 Secondary injection test
4.2.1 Test equipment
4.2.2 Example of test circuit for WIM1-H relays
4.2.3 Checking the operating and resetting values
of the relay
4.2.4 Checking the relay operating time
4.2.5 Checking the high set element of the relay
4.3 Primary injection test
4.4 Maintenance
4.5 Tripping characteristics
5 Technical Data
2
1
General
The WIM1-H is a current fed time overcurrent relay
with multi-characteristics. Definite time and inverse time
tripping characteristics can be selected. The WIM1-H
does not require an auxiliary voltage supply, consequently it can also be used for switchboards without
built-in batteries. It derives its power supply energy
from the current transformer from which, for special
applications, it can also feed the power that is necessary to give the tripping impulse to the circuit breaker.
Due to its wide setting ranges, the tripping characteristic can be selected to protect a wide variety of different equipment.
2
Characteristics and Features
• Auxiliary voltage supply is not required
• User-friendly setting procedure with wide setting
ranges
• Four 16-position setting switches for tripping current
and time
• DIP - switch to adjust the tripping characteristic,
ranges and frequency
• High measuring accuracy through an efficient
microprocessor and digital processing of the
measuring values
• High operating reliability through internal selfsupervision (watchdog)
• Protective functions selectable:definite time overcurrent protection (DMT) and inverse time overcurrent
protection (IDMT)
• Selectable INVERSE - tripping charcteristics
according to BS 142 resp. IEC 255-4:
normal inverse
very inverse
extremely inverse
• Remote tripping via external voltage
• Electro pulse output for the direct triggering of the
circuit breaker
• Tripping indication via external flag indicator with
mechanical reset
• Compact construction
• Insensitive to extreme environmental conditions
• High-accuracy components and over-rating guarantee precision, reliability and a long service life
• In accordance with the specified technical data, it
complies with the requirements of VDE - regulation
0435-303, IEC 255, VDE 0843
TB WIM1-H 07.97 E
3
Working Principle
The alternating currents induced by the mains current
transformers provide the WIM1-H's supply energy and
form the measuring value.
The measuring currents are galvanically isolated via
the input transformers, decoupled from high-frequency
interferences by analog RC-filters and then converted
into current proportional voltages. These voltages are
rectified and the rectified mean value is calculated by
the microprocessor.
Measurings are made in two steps acc. to the auto
ranging method. For very distorted current curve shape
an average value correction is provided in the short
circuit measuring range.
The A/D converter sampling frequency for the detection of the rectification mean value is 1600 Hz per
cycle (every 0.625 ms) at 50 Hz and 1920 Hz (every
0.521 ms) at 60 Hz. Depending on the mean value
and the adjusted tripping characteristic, the tripping
time, if activated, is calculated by means of a time optimised protective program. An integrated watchdog
supervises this protective program.
Figure 1 Block Diagram
➀
➁
➂
➃
➄
Setting switch for tripping characteristic
Decoder
Measuring value storage
Tripping amplifier
Flag indicator
TB WIM1-H 07.97 E
➅
➆
➇
➈
➉
Remote tripping
Tripping relays
Energy store
Saturation resistance
Trip solenoid
3
3.1
Tripping Outputs
For direct tripping of the circuit breaker from the
WIM1-H an electro pulse output is used (terminal 10+
and terminal 11-). The tripping energy is either taken
direct from the relay input measuring current or a trip
energy store. The tripping pulse on-time is 0.2 s. Concerning voltage level and energy content the tripping
pulse varies dependent on the following operational
conditions:
Remote tripping
During remote tripping a 50 V DC tripping pulse,
±10%, is sent with an energy of 2.5 Ws.
Relay input measuring currents >15A AC ±10%
Tripping via the internal trip energy store. The loading
level or pulse amplitude varying between 50 V DC
±10% (min. value) and ≈100 V DC, dependent on the
input measuring current and tripping delay. The energy
differs between 2.5 Ws and ≈10 Ws.
Relay input measuring currents <15 A AC ±10%
In case of tripping, the input measuring current is directly sent to the tripping coil of the c.b. via a rectifier
circuit. The voltage level of the tripping pulse and the
energy depend on the input measuring current and the
impedance of the tripping coil.
Each tripping consists of a cycle of 5 trip attempts with
an on-time of 0.2 s per pulse. The interval following
these attempts is necessary for recharging the internal
trip energy store (2000 µF). The time required for this
is between 0.05 s and 2.5 s max, dependent on the
relay input measuring current. The charging condition
of the trip energy store is constantly supervised during
the charging procedure. After elapsing of the tripping
delay, the trip cycle is always repeated.
3.1.1 Adaptation of Current Transformer
and Tripping Device
The tripping energy for relay input measuring currents
<15 A AC ±10 % down to the lowest tripping limit
(I> = 1A, tI> = 0.2 s) or (I>> = 2 A, tI>> = 0.05s) is
taken via a rectifier circuit directly from the relay input
measuring current or the main CT. In correlation with
the tripping coil, rating of the main CT must be such
that tripping is guaranteed at the specified lowest tripping limits. But overrating of the CT (when the type
used is too large) has to be avoided either (see para.
3.1.2).
3.1.2 Limiting of the Relay Short Circuit
Measuring Currents
In case of relatively high power consumption of the
tripping device, the main CT must be rated accordingly, especially with regard to the lowest tripping
limit. This means that the main CT is clearly overrated
in the short circuit range which gives rise to excessive
relay short circuit measuring currents. By providing additional saturation resistors in the relay measuring current path, the main CT is higher loaded in the short
circuit range, resulting in saturation of the CT. The
saturation resistors should be rated 0.5Ω to 1Ω for
100W to 150 W.
Saturation resistors must be resistant to pulses (min. ≈
1.5 kW for 1 s at R = 0.5Ω). For this application the
use of heavy-duty resistors is recommended (e.g.
DRALORIC ZBS 30/133 to ZBS 30/165).
Limiting the relay short circuit measuring currents by
means of lower rating of the main CT is only possible
if the needed tripping capacity is also reduced.
3.1.3 Average Value Correction
The relay input measuring currents are ascertained as
rectifying average value in two steps by means of the
auto ranging method. In the upper measuring range
(short circuit range), large distortions of the sine-wave
form occur which are adversely influenced by the saturation resistors. For this reason an average value correction has been provided in the upper measuring
range compensating the influence of this wave-form
distortion to the measuring value of the input current.
4
TB WIM1-H 07.97 E
3.2
Setting of the relay
All switches for the relay setting are located on the
plate of the WIM1-H. The function designation is indicated next to the switches. To adjust the values below,
four 16-position BCD switches are available:
I>
I>>
tI>
tI>>
Overcurrent pickup value
high set pickup value
trip delay for the overcurrent element
trip delay for the high set element
To select the tripping characteristic and the nominal
frequency, there is a DIP switch set. This set is designated CHAR.
Two LEDs signalize pickup of the overcurrent element
I> and the high set element I>>.
Figure 2: Front plate/wiring sceme
IMPORTANT NOTICE
it's only allowed to connect the terminals 1S1, 2S1 and 3S1 to earth.
TB WIM1-H 07.97 E
5
3.2.1 Setting of the switches
3.3
Before commissioning, it is essential to select the
nominal frequency, tripping characteristic and tripping
ranges (CHAR switches 1-8). Furthermore, the selector
switches I>, tI>, I>>, tI>> have to be adjusted to the
appropriate pickup currents and trip delays.
By means of DIP - switches 2 - 5, it is possible to select
either one of the three dependent or one independent
tripping characteristic.
3.2.2 Settings at the CHAR - switch
The equations on which the characteristics are based
are detailed on page 11, paragraph "dependent
overcurrent time protection". The following table shows
the adjustment values for the appropriate switch positions of switches I> and tI>.
The functions of the individual DIP - switches are detailed in the following table:
Switch no.
1
2
3
4
5
6
8
OFF position
nominal frequency 50 Hz
high set element blocked
range 1 for tI> (DMT)
Overcurrent tripping
The possible characteristics are shown on page 9, in
four diagrams.
ON position
nominal frequency 60 Hz
characteristic „normal inverse“
characteristic „very inverse“
characteristic „extremely inverse“
characteristic „definite time“
high set element activated
range 2 for tI> (DMT)
Table 1: Functions of the CHAR - switch
Switch
position
IDMT
I> = IN x
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
1.0
1.0
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
tI>
time factor
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
DMT
tI> [s]
range 1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
range 2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Table 2: Setting values for the overcurrent element
6
TB WIM1-H 07.97 E
3.4
Fast short-circuit tripping
3.6
In addition to the definite time or inverse time overcurrent tripping, it is possible to adjust a fast high set tripping. It has two setting ranges for the high set pickup
current (see the following table). The high set element
always has a definite time characteristic.
Switch position
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
I>> / IN
I>>
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
tI>> [s]
tI>>
0.05
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.0
1.0
1.0
1.0
1.0
Setting example
The tripping characteristic as shown below is to be
adjusted. Its sections consist of one inverse time characteristic (normal inverse) for the overcurrent tripping
(section 1) and one definite time characteristic for the
high set element (section 2). The nominal frequency is
50 Hz. The following settings must be made:
10
t[s]
1
Table 3: Setting values for the high set element
3.5
Integrated safety routine
In case of incorrect adjustment, for example if no, two,
or several characteristics have been selected, the
WIM1-H runs in a safety routine providing the lowest
tripping values. To avoid damage, the relay automatically selects the following safety setting in this mode:
Automatic safety setting
(DEFINITE TIME characteristic)
Value
I>
tI>
I>>
tI>>
Is = 1 x IN
0.2 s
2 x IN
0.05 s
0.1
1
2
3
4
5 6 7 8 9 10
20
I/IN
Fig 3: Example of a characteristic
DIPswitch
1
2
OFF
3
4
x
x
5
6
8
x
ON Function
x
x
x
x
Table 4: Automatic safety setting
nominal frequency 50 Hz
characteristic
Normal inverse
characteristic Very inverse
characteristic
Extremely inverse
Definite time characteristic
high set element active
switch position optional
(only for independent overcurrent tripping)
Table 5: CHAR-switch
TB WIM1-H 07.97 E
7
Switch
I>
tI>
I>>
tI>>
Switch position
4
3
8
2
Setting value
1.2 A
0.4 A
6.0 A
0.2 A
Table 6: Step switches
3.7
Remote tripping
4
Relay testing and
commissioning
The test instructions following below help to verify the
protection relay performance before or during commissioning of the protection system. To avoid a relay damage and to ensure a correct relay operation, be sure
that:
• the rated current of the relay corresponds to the plant
data on site.
• the current transformer circuits are connected to the
relay correctly.
• all signal circuits and output circuits are connected
correctly.
The input "remote tripping" (terminals 13 and 14) allows tripping by an external alternating voltage, e.g.
by a thermal tripping coil, a Buchholz protection or
other remote tripping commands. Bypassing the measuring circuits, this input has a direct effect on the tripping circuit. A signal 230 V/AC may only be fed for
a maximum duration of 20 minutes. The tripping time
delay depends on the input voltage (see technical
data). The input terminals are galvanically isolated
from the electronic part of the relay.
4.1
3.8
For a correct relay operation, be sure that the frequency DIP-switch (50Hz/60Hz) has been selected
correctly according to your system frequency (50 or
60Hz).
Overcurrent - short-circuit
indications
At the front plate there are two LEDs to indicate pickup
of the relay. If the adjusted pickup value of the overcurrent element I> is exceeded, the LED I> will lights
up and a calculated delay expires until the relay trips.
LED I>> lights up if high set tripping has been selected
and the additionally adjusted pickup value for I>> has
been exceeded.
3.8.1 Tripping indication by means of flag
indicator
A tripping can be indicated mechanically through the
flag indicators WI1-SZ2 and WI1-SZ3 which are optionally available. After tripping, they have to be reset
manually. For the connection of the flag indicators, see
the connection diagrams on page 5.
8
Checking the set values
Check all relay set values and see if they are set correctly as you have desired. Set values can be modified
by means of the DIP-switches on the front.
4.2
Secondary injection test
4.2.1 Test equipment
• Ammeter with class 1 or better
• Single-phase current supply unit
adjustable from 0 to ≥ 2.3 x IN (2.5 A AC)
• Timer to measure the operating time
(Accuracy ±10 ms)
• Switching device
• Test leads and tools
Important note !
The permanent load carrying capacity must not exceed 2.3 x In.
TB WIM1-H 07.97 E
4.2.2 Example of test circuit for WIM1-H
relays
0
For testing WIM1-H relays, only current input signals
are required. The following diagram shows a simple
example of a single phase test circuit with adjustable
current energizing the WIM1-H relay under test.
4.2.3 Checking the operating and resetting values of the relay
4.2.4 Checking the relay operating time
Inject a current which is less than the relay set value I>
in the phase 1, 2 or 3 of the relay and gradually increase the current until the relay starts, i.e. at the moment when the LED I> lights up. Read the operating
current indicated by the ammeter. The deviation must
not exceed ±5% of the set operating value.
Furthermore, gradually decrease the current until the relay resets, i.e. the LED I> extinguishes. Check that the
resetting current is greater than 0.97 times the operating current.
Repeat the test by means of injecting current in the
other phases in the same manner.
To check the relay operating time, a timer must be
connected to the trip output 10 - 11. The timer should
be started simultaneously with the current injection into
the current input circuit and stopped by the trip impulse. Set the current to a value corresponding to
twice the operating value and inject the current instantaneously. The operating time measured by the timer
should have a deviation of less than ±3% of the set
value or ±10 ms. Repeat the test on the other phases
or with the inverse time characteristics in the similar
manner.
In case of inverse time characteristics the injected current should be selected according to the characteristic
curve, e.g. two times IS. The tripping time may be red
from the characteristic curve diagram or calculated
with the equations given under "technical data".
Please observe that during the secondary injection test
the test current must be very stable, not deviating more
than 1%. Otherwise the test results may be wrong.
TB WIM1-H 07.97 E
9
4.2.5 Checking the high set element
of the relay
To test the high set element, its trippping delay has to
be set much longer than the tripping delay of the overcurrent element. Set a current to the set operate value
of I>>.
Set I> to 1 A.
Set I> to 2 A.
Set tI> to 1,7 s.
Set tI>> to 1 s.
Inject the current (2.3 A) and check that the LED I>>
lights up after 1 s.
Repeat the test with injected current around the operate value and seek the operate value in this manner.
Set the desired time delay tI>> of high set element. Inject a current corresponding to twice the operate value
of I>> if possible and measure the operate time with
timer in the same manner as in para. 0.
4.4
Maintenance
Maintenance testing is generally done on site at regular intervals. These intervals vary among users depending on many factors: e.g. the type of protective relays
employed; the importance of the primary equipment
being protected; the user's past experience with the relay, etc.
For electromechanical or static relays, maintenance
testing will be performed at least once a year according to the experiences. For digital relays like WIM1-H,
this interval can be substantially longer. A testing interval of two years for maintenance will be recommended.
During a maintenance test, the relay functions including the operating values and relay tripping characteristics as well as the operating times should be tested.
Note: During test of the high set element, great care
must be taken to ensure that the test currents and their
duration do not exceed the current circuit thermal withstand given in the technical data.
4.3
Primary injection test
Generally, a primary injection test could be carried out
in the similar manner as the secondary injection test
described above. With the difference that the protected power system should be, in this case, connected to the installed relays under test „on line“, and
the test currents should be injected to the relay through
the current transformers with the primary side energized. Since the cost and potential hazards are very
high for such a test, primary injection tests are usually
limited to very important protective relays in the power
system.
10
TB WIM1-H 07.97 E
5
Technical Data
Measuring input
Rated data:
nominal current In = 1A, 50/60 Hz
Power consumption in current
circuit at I = 1A =1xIN:
S = 5 VA
Thermal withstand capability
of the current circuit:
rated surge current for one half-cycle
135 x IN
rated short-period current for 1 s
54 x IN
short-period load carrying capacity for 10 s 17 x IN
permanent load carrying capacity
2.3 x IN
Input for the remote tripping
Nominal voltage:
Power consumption:
230 V/AC, max. 20 min.
6 VA/220 V
Tripping time:
dependent on the input voltage;
U = 230 V ± 20% tmax = 2.5 s
Tripping:
periodically for the input voltage range from
U = 0.8 to 1.2 UN, if no current flows
lower operating value 90 V AC, if current flows
frequency dependent on U
Accuracy
Basic accuracy
(related to the current):
Basic accuracy of the
tripping time delay:
Influence of frequency:
Influence of temperature:
± 5%
± 3% or ± 10 ms
in the range of ± 5% of the nominal frequency
the current deviation is 0.5% per Hz
0
0
± 1.5% at - 40 C to 55 C:
Specified ambient service
Temperature range for storage:
Temperature range for service:
0
0
- 40 C to + 85 C
0
0
- 40 C to + 55 C
General data
Drop-out to pickup ratio:
Returning time:
Minimal response time:
Time lag error class index E:
TB WIM1-H 07.97 E
97%
20 ms
50 ms
10 ms
11
Definite time overcurrent protection (DMT)
I>
range 1; steps
1 - 2.3 x IN; 0.1 x IN
0.2 - 1.7 s; 0.1 s
Is
tI>
range 2; steps
2 - 17 s; 1 s
Inverse time overcurrent protection (IDMT)
Tripping characteristics according to IEC255-4 (BS 142):
Normal Inverse
t=
Very Inverse
t=
Extremely Inverse
t=
with:
I>
t
tI>
I
IS
=
=
=
=
014
. ⋅ tI >
(I / Is)
0.02
−1
135
. ⋅ tI >
/
I
( Is) − 1
80 ⋅ t I >
(I / Is)
2
−1
tripping time delay
time multiplier
fault current
set value of the current
I
tI>
range 1; steps
1 - 2.3 x IN; 0.1 x IN
0.1 - 1.6; 0.1
Electro Pulse Output
Terminal 10 (+), terminal 11 (-)
Trip:
recurring cycle with 5 pulses of 200 ms each.
For currents < 15A AC ± 10 % the first pulse is not supported by
the energy store.
Depending on the relay current, intervals lasting from 50 ms up to 2.5s.
Internal trip energy store:
2000 µF / 100 V DC
(recharging 50 V DC ± 10 % up to 100 V DC ± 10 % depends on
the current).
When the upper interval limit is exceeded (2.5 s), the actual energy
storage is released for tripping
50 to 100 V ± 10 %
Output voltage:
12
TB WIM1-H 07.97 E
Tripping energy
at remote tripping:
at currents
>15A AC ±10 %:
at currents
<15A AC ±10 %:
2.5 Ws
2.5 Ws up to 10 Ws (dependent on the relay current or the stored
energy)
at 200 ms pulse on-time direct dependent on the impedance of the
tripping coil and the respective relay current. (Dependent on the relay
current or the stored energy. A reliable lowest tripping limit depends
mainly on the adjustment between main CT and tripping coil).
Indication elements
Overcurrent indication:
Short-circuit current indication:
Flag, optionally:
LED I>
LED I>>
external flag, with mechanical reset function for the
indication of a tripping
Type tests
Regulations:
VDE 0435, part 303, IEC 255-4, BS 142, VDE 843 part 2, 3, 4
high voltage tests according to VDE 0435, part 303
Insulation voltage test:
Surge voltage test:
High frequency test:
2.5 KV / 50 Hz; 1 min.
5 KV / 1.2 / 50 µs, 0.5 Ws
2.5 KV / 1 MHz
Immunity from disturbance by:
electro-static discharge (ESD)
acc. to VDE 0843 part 2
resp. IEC 801-2:
severity level 4
test voltage 8 kV
Electrical fast transient (Burst):
test acc. to VDE 0843 part 4
resp. IEC 801-4
severity level 4
test voltage 4 kV
burst duration 1 - 15 ms
spike frequency 1; 2.5; 5 KHZ
Radio interference suppression
test as per DIN VDE 57871:
limit value class B
Radiated electromagnetic field
test as per VDE 0843 part 3:
field strength 10 V/m
Mechanical tests
Shock:
Vibration:
class 1, DIN IEC 41 B (CO) 38
class 1, DIN IEC 41 B (CO) 35
Enclosure, housing, installation
Protection class:
Material:
Width, height, depths:
Fastening type:
Weight:
Installation position:
order designation:
TB WIM1-H 07.97 E
electronics: IP 40
signal and control terminals: IP 20
transformer connection terminals: IP 00
Macrolon 6030, self-extinguishing
see dimensional drawings
with screws
1.8 kg
optional
WIM1-H1-EL2
13
5.1
Tripping characteristics
100
100
10
10
t[s]
tI>=
t[s]
1.6
1.4
1.2
1.0
0.8
tI>=
1.6
1.3
1.0
0.8
0.6
0.5
0.4
0.3
1
0.6
0.5
0.4
1
0.3
0.2
0.2
0.3
0.1
0.1
0.1
1
2
3
4
5 6 7 8 9 10
20
1
2
I/IS
3
4
5 6 7 8 9 10
20
I/IS
Fig. 4: Normal inverse
Fig. 6: Very inverse
100
100
10
10
t[s]
tI>=
1
1
0.1
0.1
0.01
t[s]
1.6
1.3
1.0
0.8
0.6
0.5
0.4
0.3
0.2
0.1
0.01
1
2
3
4
5 6 7 8 9 10
20
1
Fig. 5: Extremely inverse
14
10
100
I/IN
I/IS
Fig. 7: Definite time
TB WIM1-H 07.97 E
Fig. 8: Dimensional drawing WIM1-H
Installation depth: 110 mm
Flag indicator WIZ-SZ2
TB WIM1-H 07.97 E
15
Flag indicator WIZ-SZ3
16
TB WIM1-H 07.97 E
Woodward SEG GmbH & Co. KG
Krefelder Weg 47 ⋅ D – 47906 Kempen (Germany)
Postfach 10 07 55 (P.O.Box) ⋅ D – 47884 Kempen (Germany)
Phone: +49 (0) 21 52 145 1
Internet
Homepage http://www.woodward-seg.com
Documentation http://doc.seg-pp.com
Sales
Phone: +49 (0) 21 52 145 635 ⋅ Telefax: +49 (0) 21 52 145 354
e-mail: kemp.electronics@woodward.com
Service
Phone: +49 (0) 21 52 145 614 ⋅ Telefax: +49 (0) 21 52 145 455
e-mail: kemp.pd@woodward.com