Electronic motor protection relay - NHP

Refer catalogue CT
CET 4
CWE 4 -180
CWE 4-630
CET 4 option cards
CUD 4
CPA 4 / CET3-CET 4
adaptor plate
Electronic motor protection relay
Type CET 4 - ordering information
Description Cat. No.
CET 4
CET 4 basic unit panel mounted 1 )
CET 4 basic unit panel mounted 2 )
CET 4 + earth leakage for NSW MDA 14081 approved to AS 2081.3
Current converters type CWE 4 (required for each CET 4 unit) 3 )
0.5 to 2.5 amps or for use with 1 amp secondary current
transformers (customers own CT’s)
2.5 to 20 amps or for use with 5 amp secondary current
transformers (customers own CT’s)
20 to 180 amps 4 )
160 to 630 amps standard type
160 to 630 amps (new version)
Option cards 5 ) supplied without connector sets
Option card for DeviceNet communications
Profibus card for CET 4
Option card for modbus communications
Option card for remote I/O communications
Profibus card for personal computer 6 )
(includes ‘Visu’ software)
Option card CST 4
(add ‘S’ to Cat. No. or order separately)
Option card CLV 4
(add ‘L’ to Cat. No. or order separately)
Option card CMV 4 (RTD)
(add ‘M’ to Cat. No. or order separately)
Surface mounting set for CET 4
Analogue output meter - use with option card 72 mm
CST 4 (4-20 mA motor temperature rise) 96 mm
CET 4 user manual - contains set up instructions application
data and diagnostic information
Adaptor plate for fitting CET 4 in place of CET 3
(metal plate colour grey RAL 7035)
CET 4 test unit for periodic performance testing of CET 4
protection relays
CET 4 key switch - panel mounted (prevents unauthorised
setting changes) [Lockout - reset - Normal - Emg start]
Notes: 1 ) CET 4 can be supplied with option cards
and control transformers 24, 36, 48,110,
240 and 415 V AC.
2 ) CET 4 can be supplied with option cards
and power modules 24 - 48 V,120,
and 220 V DC (extra price) power supplies.
3 ) Supplied complete with 5 metre
connection lead for plug-in to CET 4 unit.
4 ) CWE 4-180 has CT openings for motor
cable- for connection bars.
5 ) It is preferable that CET 4 option cards
are fitted by NHP however customer
retrofit is possible.
i
CET 4/…V AC
CET 4/…V DC
CET 4/…V AC/MD
CWE 4-2.5A
CWE 4-20A
CWE 4-180A
CWE 4-630A
CWE 4-630N
CDN4
CPB 4
CMB 4
CRI 4
CPC 4
CST 4
CLV 4
CMV 4
CPM 4
CUD 4-72
CUD 4-96
CUM 4-SS
CPA 4
CTU 4
LE 2-12-10028
6 ) CPC 4 card can communicate with up to
31 CET 4 units.
i
Available on indent only.
240/415 V rated power supplies are
suitable for use on 230/400 V in
accordance with AS 60038 : 2000.

Refer catalogue CT
Cat. No. CET 4
Cat. No. CWE 4
Rear view of CET 4 showing
option cards being installed
Electronic motor protection relay
Type CET 4 - general information
CET 4 - a new standard in motor protection
The new microprocessor based electronic motor protection relay CET 4 continues the
successful tradition of Sprecher + Schuh in the field of high quality motor protection.
The CET 4 offers first class motor protection by use of the proven two body thermal
representation. An extension of this system includes consideration of asymmetrical
conditions and a facility for ambient or cooling temperature feedback if required.
CET 4 - the ideal component for modern control systems
Besides a variety of protection functions for different requirements, the microprocessor used
gives way for the integration of the CET 4 into control systems. It provides information and
functions that conventionally were difficult or costly to realise. Clear text readout in English
on the relay (LCD display), and a communication option make setting, monitoring, failure
tracking and data logging a simple task.
All functions are easy to set and understand and the basic version can be extended by
means of plug-in cards where additional control functions are required.
Protection functions (basic unit)
❍ Full thermal protection with thermal equivalent model
❍ Asymmetry protection and phase failure detection
❍ High overload or stalling protection
❍ Underload protection
❍ Earth fault protection
❍ Start time and starts per hour supervision
❍ Warm start protection
Special settings and features (basic unit)
❍ Selectable auto/manual reset of thermal trip
❍ Adjustable thermal reset level
❍ Cooling constant ratio motor on/off adjustable
❍ Failsafe or non failsafe operation of trip relay
❍ Emergency start facility (modifies copper memory only)
❍ Remote reset facility is standard
❍ Alarm relay fitted on basic unit
❍ Set-up disable input (security of set values)
Current converter modules type CWE 4
Only four CWE 4 current converter modules are required to cover the range of 0.5 to
630 amps. Secure operation is assured as the CWE / CET 4 link is continuously monitored.
The CET 4 also checks compatibility of the set current to the connected CWE module. Use
on high or low voltage motors is possible.
Adjustable warning functions (basic unit)
❍ Thermal overload pre-warning
❍ Asymmetry level
❍ High overload (approaching stall)
❍ Earth fault
❍ Underload activated
Modular design for flexibility
The modular system design permits economical and appropriately specified solutions:
❍ Extra features can be added as required
❍ Plug-in option cards allow the operational requirements to be optimally matched
❍ The current converter module covers a wide range. This simplifies selection and planning

Refer catalogue CT
CET 4 display – actual values.
CET 4 display – set values
CET 4 display – recorded
values
Typical CET 4 option card
Electronic motor protection relay
Type CET 4 - general information
Operating data display (actual values)
Comprehensive information can be displayed on the LCD display in plain text to facilitate and
simplify management of operations. The following data can be requested:
❍ Average motor current ❍ Individual phase currents
❍ Thermal utilisation percent ❍ Time to trip (if in overload mode)
❍ Asymmetry percent ❍ Earth current
❍ Time to reset (if tripped) ❍ Temperature levels (if used)
Set parameters display (set values)
Setting the parameters (set points) on a clear LCD display requires only four keys. The
result:
❍ The CET 4 is simple and fast to set up - initially and during operation
❍ Simple and rapid malfunction tracing
❍ Up to 130 set points and adjustments are available from the front keypad
Note: The front keypad is protected to IP 65 as standard
Statistical data (recorded values)
The basic CET 4 stores all important data in non volatile memory (EEPROM). The internal
elapsed time clock operates for up to eight hours on loss of control voltage. This allows the
re-calculation of motor thermal capacity when the control supply is restored and provides a
means of logging the time and duration of momentary power failures. The statistical data
recorded includes:
❍ CET 4 operating time ❍ Time since last trip
❍ Motor running hours ❍ Time since four previous trips
❍ Time since last start ❍ Cause of last trip
❍ Time since the four previous starts ❍ Cause of four previous trips
❍ Number of starts ❍ Number of trips on each function
❍ Current, asymmetry, earth current, max. temperature before last trip
Option cards
CMV 4 option card CPB 4 option card
❍ Six RTD inputs (PT 100) RS 485 profibus communication card for
❍ One ambient input (PT 100) CET 4.
CLV 4 option card CPC 4 option card
❍ Phase sequence input RS 485 profibus communication card for
❍ Two extra output relays which can personal computer.
be programmed for auto star/delta
starter control or for other functions
❍ Complete with ‘visu’ software
CST 4 option card
❍ Earth leakage using core balance ❍ Three extra (assignable) output relays
transformer ❍ Two control inputs for special functions
❍ PTC thermistor input ❍ 4-20 mA analogue output for motor
❍ Relay for short circuit protection temperature rise
Communication cards
❍ DeviceNet
❍ Profibus (FMS)
❍ Modbus
❍ Remote I/O

Refer catalogue CT
CET 4 basic unit
Option card CPB 4
Electronic motor protection relay
Type CET 4 - ordering information
Catalogue Number structure CET 4 main unit
Basic unit
Control voltage
24 V AC
36 V AC
48 V AC
110 V AC
230/240 V AC
400/415 V AC
24-48 V DC
110 V DC
Option card
S = CST 4
Option card
L = CLV 4
} Only one of these cards can be used
M = CMV 4
Option card (communications)
D = CDN 4 Device net card
P = CPB 4 Profibus card (FMS)
B = CMB 4 Modbus card
R = CRI 4 Remote I/O card
CET 4 / . . . . / S / L / P
Basic unit main features
Thermal overload, asymmetry, high overcurrent/stalling, underload, earth fault, warm start,
emergency start, start time monitoring, alarm contact, remote reset, operating data display
(LCD), statistical data, adjustable trip and warning levels, starts per hour inhibit, setting
disable input.
CST 4 option card
Provides additional output relays Nos 1, 2, 3, programmable to any function. Input for core
balance current transformer (earth leakage). Input for thermistor (PTC), two control inputs for
selectable functions including new full load current (two speed motor application), speed
switch (stall during start protection), on/off delay timers, disable of selected protection
functions. 4-20 mA analogue output for motor temperature rise. Use of short circuit
protection function via relay No. 1.
CLV 4 option card (cannot be used if CMV 4 card is installed)
Provides additional output relays Nos 4 & 5, programmable to any function or assigned for
automatic star delta starter control (changeover based on time or when current drops below
1.1 x I e).
❍ Provision for phase sequence (voltage) input and also functions as voltage loss
protection on one phase. (Normal phase failure protection is via asymmetry)
CMV 4 option card (cannot be used if CLV 4 card is installed)
Provides six RTD inputs (PT 100) for stator or bearing temperature measurement. A further
RTD input is provided for ambient or coolant temperature input (considered in thermal
model).
Communications cards
❍ CDN 4 DeviceNet card
❍ Profibus communication card (FMS)
❍ CMB 4 Modbus card
❍ CRI 4 remote I/O card
Note: 240/415 V rated power supplies are suitable for use on 230/400 V in accordance
with AS 60038 : 2000

Refer catalogue CT
Electronic motor protection relay
Type CET 4 - dimensions and mounting
CET 4 panel mounted 1 ) CET 4 flush mounting
10
144
144
max. 6 mm
Note: 1 ) Using optional CPM mounting set. Mounting depth 139 mm (allow for wiring)
CWE 4-180
Without busbars Straight busbars For use with CA 6
The motor leads can be fed directly
through the openings of the current
monitoring module.
I e = 20…180 A
IEC conductor cross-section:
4…95 mm2. CWE 4-2.5
CWE 4-20
ø max, 19 mm
Generally CWE 4-2.5 and CWE 4-20
are used for secondary applications
with additional main current
transformers.
For 1 A secondary CTs use CWE 4-2.5.
For 5 A secondary CTs use CWE 4-20.
sprecher +
schuh
CET 4
138 +1 -0
138 +1
-0
10
139
137
149

Refer catalogue CT
CWE 4-630N
Control circuit (basic unit)
Electronic motor protection relay
Type CET 4 - dimensions and wiring
Main connections CET 4 - CWE 4
Direct connection of CWE
(primary application)
CET 4
Connection of main
CT’s to CWE 4
Dimensions (mm)
a b c c1 ød d1 d2 d3 øe øe1 e2
155 145 156 118 6.3 6.3 135 88 11 M10 48
K1 Contactor CA
F1 Electronic motor protection relay CET 4
S1 On button
S0 Off button
Us Control voltage
H1 Indicator “contactor closed”
H2 Indicator “CET 4 tripped”
MR Main output relay
AL Alarm relay
H3 Indicator “alarm / warning”
Connection of CT’s and core balance CT
(also possible with 3 main CT’s)

Refer catalogue CT
Connection diagram
PT
100
# 1
PT
100
# 2
PT
100
# 3
PT
100
# 4
PT
100
# 5
PT
100
# 6
PT
100
# 7
Front keypad
Electronic motor protection relay
Type CET 4 - technical information
CMV 4 / CLV 4 CST 4 Basic
1T1
1T3
1T2
2T1
2T3
2T2
3T1
3T3
3T2
4T1
4T3
4T2
5T1
5T3
5T2
6T1
6T3
6T2
7T1
7T3
7T2
1 3 5
CWE 4
2 4 6
M
3 ~
Aux
Relay # 4
Aux
Relay # 5
T
F
100 mA
F
53
54
63
64
100 mA
L1
L2
L3
L1
L2
L3
Aux
Relay # 1
Aux
Relay # 2
Aux
Relay # 3
A 4… 20 mA
23
24
33
34
Control — Y31
Input # 1 — Y32
Control — Y41
Input # 2 — Y42
PTC
— T1
— T2
Core — K
Balance — I
43
44
Main Relay MR
Supply
Emerg.
Start
Disable
Settings
Remote
Reset
Alarm
Relay AL
Non-Fail-Safe Fail-Safe
A1-
A2+
The electronic motor protection system CET 4 is very easy to operate. With six
foil keys and the LCD, all functions, data and tests can be entered, executed or
displayed. On the single-line LCD all available data and functions are displayed.
1 Values: Selection of mode.
Actual values: Indication of actual operational data.
Set values: Setting mode (set/vary, store parameters).
Recorded values: Indication of statistical data.
97
98
95
96
Y11
Y12
Y13
Y21
Y22
2 Select: Select function and enter/change operating parameters.
3 Settings: Enable entry (change) and memorise (enter).
4 Test: Test functions.
5 Reset: Reset trips.
6 LCD: Single line.
Two lines of text are displayed alternately.
7 Fault indicator (LED).
Flashing: Warning.
Steady state: Trip.
13
14
95
96
97
98

Refer catalogue CT
Protective functions
Description
Basic unit CET 4
Thermal overload
Asymmetry (phase failure)
High overload / stalling
Underload
Underload delayed enable
Earth fault (Holmgreen)
Starting time monitor
Limited starts per hour
Optional board CST 4
Short circuit
Earth fault (core balance c.t.)
Stalling during start 2 )
Thermistor input (PTC)
Optional board CLV 4
Phase sequence (voltage)
Phase failure (voltage)
Optional boards CMV 4
PT 100 input #1…#6 (stator, bearings)
PT 100 input #7 3 )
Electronic motor protection relay
Type CET 4 - technical data
Function
Factory
setting
On
On
On
Off
On
On
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Setting
range
25…100 %
-
10…100 %
-
1…10
4…12 I e
5…500 mA
-
-
-
-
50…200 °C
-
Factory
setting
0.5-2000 A 4 ) 20 A
5…80 % 35 %
1…6 I e 2.4I e
75 %
-
50 %
-
2
10 I e
5 mA
-
-
-
-
50 °C
-
Tripping delay/time
Factory
Range setting
1-600 s 5 )
1…25 s
0.1…5 s
1…60 s
0…240 s
0.1…5 s
1…240 s
-
Warning functions
Note: The level to which the warnings are set must be such that the alarm picks up before the trip.
-
-
-
-
10 s
2.5 s
0.5 s
10 s
0 s
0.5 s
10 s
-
20…990 ms 50 ms
0.1…5 s 0.5 s
-
-
-
260 ms
Basic unit CET 4
Thermal utilisation (%∆ϑ load) Off
Asymmetry (% I e)
Off
High overload (I e)
Off
Underload
Optional board CST 4
Off
Earth fault (core balance C.T.) Off
Off
Notes: 1 ) One relay per function can be selected: MR = Main relay, AL + Alarm relay, relays 1…5.
2 ) Via external speed switch (control input 1), output relay as per high overload.
3 ) Allowing for the ambient temperature in the thermal image.
4 ) Also use as a secondary relay (any current with CT ratios selected).
5 ) Locked rotor current also adjustable 2.5 - 12 x Ie.
6 ) Primary sensitivity – CT ratio can also be selected.
6 50…99 % 75 % -
5…80 % 20 % -
1…6I e 2I e -
25…100 75 % -
)
Optional board CMV
5 mA…50 A 1 A -
PT 100 input #1…#6 (stator, bearings)
50…200 °C 50 °C -
1 s
2 s
< 3 s
-
-
-
-
-
-
-
Relays 1 )
selection
MR
All
All
All
-
All
All
All
#1
All
All
MR
All
All
All
-
Factory
setting
MR
MR
MR
MR
-
MR
MR
MR
-
MR
MR
MR
MR
MR
MR
-
AL,#1…#5 AL
AL,#1…#5 AL
AL,#1…#5 AL
AL,#1…#5 AL
AL,#1…#5 AL
AL,#1…#5 AL

Refer catalogue CT
Control functions
Description
Basic unit CET 4
Warm start (% of ‘cold’ trip)
On
Emergency override of thermal trip
Option board CST 4
Off
On
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
3 )
Analog output motor current
Analog output therm. utilisation
Analog output PT 100 temperature
Control input #1: (24 V AC/DC; 8 mA)
Alternatively one of 3 functions
can be selected:
❍ Pickup delay, relay #2
❍ Dropout delay, relay #2
❍ Switch off prot. functions:
- Asymmetry / phase failure
- High overload/stalling
- Earth fault
- Short circuit
- Underload
- Limit starts/hour
- PTC
- PT 100
Control input #2: (24 V AC/DC; 8 mA)
Alternatively one of 4 functions
can be selected:
❍ Pickup delay, relay #3
❍ Dropout delay, relay #3
❍ Set 2nd rated current 2 )
- Asymmetry/phase failure
- High overload/stalling
- Earth fault
- Short circuit
- Underload
- Limited starts/hour
- PTC
- PT 100
Optional board CLV 4
Star delta starting
Electronic motor protection relay
Type CET 4 - technical data
Function
Factory
setting
Setting
range
50…100 %
Jumper term.
4…20 mA (20 mA=200 % Ie, 12 mA=100 % Ie)
4…20 mA -
- -
4…20 mA (20 mA=200 °C, 12 mA=100 °C)
-
-
-
-
-
-
-
-
-
-
-
-
-
0.5…2000 A
-
-
-
-
-
-
-
-
Factory
setting
70 %
Y11-Y12
-
-
-
-
-
-
-
-
-
-
-
-
-
20 A
-
-
-
-
-
-
-
Y-∆ at
1.1 I e
Tripping delay/time
Factory
Range setting
4…60 min 60 min
- -
0…240 s
0…240 s
-
-
-
-
-
-
-
-
-
0…240 s
0…240 s
-
-
-
-
-
-
-
-
Y-∆ at
1…240 s
Notes: 1 ) One relay per function can be selected: MR = Main relay, AL + Alarm relay, relays 1…5.
2 ) Eg. two-speed motors.
3 ) Analogue output can be selected for either thermal utilisation, motor current or PT 100 temperature.
0 s
0 s
-
-
-
-
-
-
-
-
-
0 s
0 s
-
-
-
-
-
-
-
-
10 s
Relays 1 )
selection
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Factory
setting
-
-
#2
#2
-
-
-
-
-
-
-
-
-
#3
#3
-
-
-
-
-
-
-
-
Y: #4
∆: #5

Refer catalogue CT
Electronic motor protection relay
Type CET 4 - technical information
Ambient conditions
Temperature
Operation -5…+60 °C
Storage -40…+60 °C
Transport -40…+85 °C
Climatic sensitivity
Damp heat IEC 68-2-3 40 °C, 92 % Relative humidity, 56 days
Climatic cycling IEC 68-2-30 25/40 °C, 21 cycles
Degree of protection
CET 4, enclosed in panel IP 65
Terminals IP 20
Resistance to vibration
- as per IEC 68-2-6 10 … 150 Hz, 3 g
Resistance to shock
- as per IEC 68-2-27 30 g, shock duration 18 ms, semisinusoidal
in x, y, z - directions
Nominal rated voltages U e
Primary circuit of detection
CWE 4-2.5 A; CWE 4-180 A;
CWE 4-20 A; CWE 4-630 A
Motor circuit
- as per IEC, SEV, VBE 0660 660 V AC 1000 V AC
- as per CSA, UL 600 V AC 600 V AC
Control circuits
Main relay (MR) 95…98, supply A1, A2
Phase sequence protection L 1, L 2, L3
- as per IEC 947 400/415 V AC
- as per SEV 380 V AC
- as per UL, CSA 230/240 V AC
Alarm relays (AL) 13/14
Auxiliary relays #1, #4, #5
- as per IEC 947 400/415 V AC
- as per SEV 250 V AC
- as per UL, CSA 240 V AC
Auxiliary relays #2, #3 50 V AC / 30 V DC
Control inputs #1, #2 24 V AC / 24 V DC
Electrical tests
Test voltage CWE 4-2.5 A; CWE 4-180 A;
CWE 4-20 A; CWE 4-630 A
Motor circuit
- as per IEC 947-1 U imp 6 kV, U imp 8 kV
Control circuit
Between control circuits and to all other circuits 1 )
Main relay (MR) 95…98, supply A1, A2
Phase sequence protection L 1, L 2, L 3
Alarm relay (AL), Auxiliary relays #1…5
Control inputs #1, #2
Core balance c. t. k, l
- as per IEC 947-1 U imp 4 kV
EMC standard
Noise emission as per EN 50081-1/2
Noise proof as per EN 50082-1/2
Supply
Nominal supply voltage U e
50/60 Hz, 110 V AC; 220…240 V;
400…415 V; 440 V
DC 24…48 V, 110 V/120 V, 220 V
Permissible voltage fluctuation AC 0.85…1.1 U e
DC 0.8…1.1 U e
Power consumption AC 13 VA
DC 10 W max.
Short-circuit protection appropriate conductor cross section of cable.
The supply module is proofed against short
circuits.
Note: 1 ) The measuring inputs for PT 100 and PTC, the 4…20 mA output and the RS 485 interface
are not insulated from one another.
240/415 V rated power supplies are suitable for use in 230/400 V in accordance with
AS 60038 : 2000

Electronic motor protection relay
Type CET 4 - technical information
Relays
Contact data of output relays
Main relay (MR) 95…98
Contacts fitted 1 N/C and 1 N/O galvanically separated
Service voltage [V] 24 48 60 110 220/230 230/240 380
400/415
- as per UL, CSA: pilot duty 240 V
440
Continuous thermal current [A] 4 4 4 4 4 4 4 4 4
Rated service current on AC
Rated service current on DC
[A] 4 4 4 4 3 3 2 2 1.5
- without prot. network, L/R = 35 ms [A] 0.6 0.3 0.25 0.15 0.05 0.05 - - -
- with prot. network 1 ), L/R = 100 ms [A] 0.6 0.6 0.5 0.5 0.5 0.5 - - -
Max. permissible switching current [A] 44 44 44 44 33 33 22 22 16.5
Alarm relay (AL), auxiliary relays #1, #4, #5
Contacts fitted 1 N/O each
Continuous thermal current 4 A
Max. permissible switching voltage
Nominal service current
400/415 V AC, 125 V DC
- cosϕ = 1 4 A at 250 V AC and 30 V DC
- cosϕ = 0.4 L/R = 7 ms
Max. switching power
2 A at 250 V AC and 30 V DC
- cosϕ = 1 1250 VA, 150 W
- cosϕ = 0.4 L/R = 7 ms 500 VA, 60 W
- as per UL / CSA
Auxiliary relays #2, #3
230/240 V, 1A pilot duty
Contacts fitted 1 N/O each
Continuous thermal current 4 A
Max. permissible switching voltage
Max. switching power
30 V DC / 48 V AC
- cosϕ = 1 150 W
- cosϕ = 0.4 L/R 7 ms
Terminals
60 W
CET 4 plug-in terminals Range of cross-section: 0.5…2.5 mm2 , single wire
0.5…1.5 mm2 , double wire
- as per UL 2.2…14 AWG
- as per VDE nominal 1.5 mm2 Main circuit
- CWE 4-2.5 A / CWE 4-20 A Terminals
- CWE 4-180 A Insertion opening or current bars 20 x 4 mm
- CWE 4-630 A Current bars 25 x 8 mm
Main current transformers for the motor circuit
When CET 4 is used as a secondary relay with CWE 4-2.5 A / CWE 4-20 A
Recommended CT in the phases
Min. nominal service voltage Nominal service voltage of motor
Min. rated primary current I 1n
Nominal service current of motor
Rated secondary current 1 A or 5 A
Class and nominal overcurrent factor 5 P 10 ext. 120 % 2 )
Power rating According to power consumption in leads and measuring circuit
Rated frequency 50/60 Hz
Burden: CET 4 + CWE 4-2.5 A CET 4 + CWE 4-20 A
- Power consumption at max. rated current 3 Refer catalogue CT
) 0.1 VA/phase 0.4 VA/phase
- Thermal limit current continuous 3 A 24 A
- Thermal limit current 1 s 250 A 600 A
- Frequency of input current
General notes on CWE 4
50/60 Hz 50/60 Hz
No-load
Core balance current transformer
Recommended data for core balance CT
Secondary no-load permitted, as burden is mounted in detection module
Nominal ratio
Burden: measuring circuit CET 4
Kn =
minimum detectable earth-fault
pickup current of earth-fault prot. CET 4
- Power consumption at rated current (0.5 A) 0.4 VA
- Limiting thermal current, continuous 0.5 A
- Limiting thermal current for 1 s 25 A
- Frequency of input current 50/60 Hz
Notes: 1 ) Max. rated current of fuse: rapid (D) 16 A; slow (DT) 10 A.
2 ) Protection current transformer (P = protection) ± 1 % error at rated current; ± 5 % error at rated overcurrent (10 x rated current).
Rated thermal current = 120 % rated current (if I e motor > 87 % of rated current transformer current).
With starting current 10: I e: class 5 P 20. The current transformer error adds up to the CET 4 error.
3 ) 2.5 A with CWE 4-2.5 A, 20 A with CWE 4-20 A.
240/415 V rated power supplies are suitable for use on 230/400 V in accordance with AS 60038 : 2000