ZJJ Series Insulation Monitoring Relay
ZJJ – 4SC DC Insulation Monitoring Relay
The ZJJ – 4SC DC insulation monitoring relay is a fully static
circuit device that has a highly sensitive grounding resistance
monitoring and display circuit. It allows users to make a
quantitative assessment of the reduction of the insulation degree
of the DC busbar and monitors the grounding resistance of the
positive and negative busbars online in real-time. The relay sends
out a warning signal when the insulation drops below the set
value.
Working Principle
The relay uses the bridge balance method to measure the ground
resistance on one side. R1 and R2 are balanced resistors to realize
balanced voltage division at point A. RL is the current measurement
sampling resistance. When a unilateral insulation voltage drop
occurs, that is when there is RX or RY, the grounding current
produces a positive or negative voltage drop Vo on RL. The size and
direction of this voltage drop is measured and calculated through
the hardware voltage divider circuit to obtain the resistance value
of RX or RY. An alarm will be triggered when any resistance value
exceeds the limit.
Features
- Positive and negative busbar grounding resistance value direct
LCD - Alarm resistance threshold online display and direct
setting - Bridge balance method for resistance measurement
- Terminals are pluggable for easy maintenance and
replacement - Various packaging structures, reinforced shell, modular
structure, high reliability - Wide monitoring voltage, 48-1500v, working voltage 24-220v can
be customized
Applications
The ZJJ – 4SC DC insulation monitoring relay is widely used in
DC speed regulating motors, solar power generation, and other
fields.
Usage Instructions
When using the ZJJ – 4SC DC insulation monitoring relay, it is
essential to read the user manual carefully and understand all
implications and operations correctly. Follow the instructions in
the user manual to make better use of the device and solve any
problems that may arise.
The device uses a bridge balance method to measure the ground
resistance on one side. It directly displays the positive and
negative busbar grounding resistance value on the LCD, and the
alarm resistance threshold is online display and direct setting.
The terminals are pluggable for easy maintenance and replacement.
The device comes in various packaging structures, reinforced shell,
modular structure, and high reliability. The device can monitor a
wide voltage range of 48-1500v, and the working voltage of 24-220v
can be customized.
ZJJ – 4SC
User Manual
DC Insulation Monitoring Relay
User Manual
Version:1.0
Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
Revision 2023.04 Email:[email protected]
User Manual
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When you use ZJJ 4SC DC insulation monitoring relay, be sure to read this user manual carefully, and be able to fully understand the implications, the correct guidance of operations in accordance with user manual, which will help you make better use of ZJJ 4SC DC insulation monitoring relay, and help to solve the various problems at the scene.
1.Always keep safe distance between the instrument and operator. 2.Measurements must not be taken when thunderstorms are nearby. 3.Do not operate the instrument or accessories in explosive atmospheres. 4.Do not open the instrument without permission, this will affect the warranty of the product. The factory is not responsible for self-disassembly. 5.When the instrument is transported, it should avoid rain erosion and prevent collision and falling. 6.When storing and keeping the instrument, attention should be paid to the ambient temperature and humidity, and it should be protected from dust, moisture, shock, acid, alkali and corrosive gas.
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Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
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User Manual
Directory
1.- SUMMARIZE ……………………………………………………………………………………………………………………….. – 3 2.- TECHNICAL PARAMETERS ………………………………………………………………………………………………… – 5 3.- INSTALLATION AND TERMINAL DEFINITION…………………………………………………………………… – 6 4.- OPERATING INSTRUCTIONS ……………………………………………………………………………………………… – 8 5.- SAFETY CONSIDERATIONS ………………………………………………………………………………………………… – 9 6.- TECHNICAL SERVICE…………………………………………………………………………………………………………. – 9 –
Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
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User Manual
1.- SUMMARIZE
The ZJJ – 4SC DC insulation relay adopts a fully static circuit, and has a highly sensitive grounding resistance monitoring and display circuit, which helps users make a quantitative assessment of the reduction of the insulation degree of the DC busbar, and monitors the grounding resistance of the positive and negative busbars online in real time. When the insulation drops below the set value, the relay sends out a warning signal.
Due to the use of a full-hardware divider calculation circuit, it can directly display the grounding resistance value, which solves the confusion caused by the old relays that have no display or can only display the grounding current, and must manually check the table; the alarm threshold also uses the resistance value. directly displayed. ZJJ-4SC adopts din rail installation, are widely used in DC speed regulating motors, solar power generation and other fields.
WORKING PRINCIPLE
The relay uses the bridge balance method to measure the ground resistance on one side, as shown in the figure below. R1 and R2 are balanced resistors to realize balanced voltage division at point A. RL is the current measurement sampling resistance.
When a unilateral insulation voltage drop occurs, that is, when there is RX or RY, the grounding current produces a positive or negative voltage drop Vo on RL. Measure the size and direction of this voltage drop and calculate it through the hardware voltage divider. circuit, the resistance value of RX or RY can be obtained. An alarm will be triggered when any resistance value exceeds the limit.
Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
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User Manual
FEATURES
Positive and negative busbar grounding resistance value direct LCD; Alarm resistance threshold online display and direct setting; Bridge balance method for resistance measurement; Terminals are pluggable for easy maintenance and replacement; Various packaging structures, reinforced shell, modular structure, high reliability; Wide monitoring voltage, 48-1500v, working voltage 24-220v can be customized.
APPLICATIONS
DC or AC/DC main circuits; UPs systems, battery systems; IT systems with high leakage capacities; DC charging stations for electric vehicles; Monitoring the insulation of electrical equipment; Supporting use of power transformers, generators, and motors; Remote monitoring system, real-time monitoring of insulation conditions; Substations, power plants, transmission lines, distribution lines.
Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
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2.- TECHNICAL PARAMETERS
Parameters Symbol Conditions
Min. Typical
User Manual
Max.
Units
Operating
Vo ZJJ-4SC-220 100
220
350
V
voltage range
Power supply
Io 85-265 Vac/dc
7
10
mA
Relay capacity VA
2A@250vac
A
Resistance
measurement
Ro
0.0
range
Grounding
short-circuit
Io
Vo=2000V
current
Measurement accuracy
Vo=1000V
Alarm setting
Rs
0.0
range
Moves back coefficient
Output contact capacity
Rs=50K
95%
Inductive =5mS
Resistive load
1999
K
0.6
mA
5%
990
K
98% DC220V 0.2A DC220V 2A
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3.- INSTALLATION AND TERMINAL DEFINITION
Dimension: L x W x H:115 x 90 x 40mm, Standard 35mm Din rail.
User Manual
Front view
Side view
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User Manual
Terminal definition: Terminal No.1 is connected to the positive busbar, No. 2 and No. 3 are grounded, No.4 is connected to the negative busbar, and No.5-6 are output alarm dry contacts.No.7-8 is the working power input.
Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
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User Manual
4.- OPERATING INSTRUCTIONS
Under normal circumstances, the “POWER” light is on, the “SET” light is off, and the LCD displays the current grounding resistance value. The “+” sign before the number indicates the positive busbar grounding resistance, and the “-” sign indicates the negative busbar grounding resistance.
When the grounding condition is good, when the grounding resistance is greater than the default value of 35K, the highest digit displays a positive or negative “1”, indicating that the insulation resistance is infinite at this time, which is the same as the display of electric resistance of ordinary digital multimeters.
When the grounding resistance is less than the set default value of 35K, the display exceeds the limit, the highest digit displays positive or negative “1”, and displays the specific resistance value. The red light of “ALARM” is on, and the relay operates to send out an alarm signal.
Note:
When the last ground fault was positive bus grounded, the “+” sign will continue to be displayed on the screen even if the fault recovers; the same is true for negative bus grounded. When there is no grounding, the signs “+” and “-” will be displayed randomly after power on.
Alarm value setting:
Press and hold the SET key, the “SET” light will be on, and the LCD will display the current set value; use a small screwdriver to turn the potentiometer knob on the panel, and the set value will change continuously.
The alarm function will be disabled when the set button is pressed. When in the “measurement” state, avoid blindly adjusting the setting potentiometer, so as to prevent the action threshold from being at an undesired value and affecting the normal alarm.
Tel: +0086-023-67628702 www.cqbluejay.com Add: 1802,Building 2,No.88,Jianxin East Road,Chongqing,400020,China
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5.- SAFETY CONSIDERATIONS
User Manual
All installation specification described at the previous chapters named: INSTALLATION AND STARTUP, INSTALLATION MODES and SPECIFICATIONS.
Please note that with the instrument powered on, the terminals could be dangerous to touching and cover opening actions or elements removal may allow accessing dangerous parts. This instrument is factory-shipped at proper operation condition.
The device must have a professional installation and maintenance. Any operation of the device, you must cut off the input signal and power;
6.- TECHNICAL SERVICE
For any inquiry about the instrument performance or whether any failure happens, contact to Blue Jay’s technical service.
Blue Jay – After-sales service
1802, Building 2, No.88, Jianxin East Road, Chongqing,400020, China
Tel – + 0086 023 67628702 E-mail: [email protected]
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