产品中心
NDW300 series protection device
NDW300 series protection device

NDW300 Series protection device

Ac current :5A, 1A
Ac voltage :100V
Ac frequency :50HZ
Dc voltage :220V, 110V
Ac current loop :IN=5A
No more than 0.5VA per phase
Ac voltage loop :U=UN
Each phase is not greater than :0.2VA
Dc power supply circuit: normal operation is not more than 8 w
Protection action: no more than 10W

Product overview

NDW300 series distributed microcomputer protection monitoring device is based on the "one device (one interval) one device" fully decentralized design mode developed on the switch cabinet protection monitoring device.The device case is designed with compact structure, good sealing, anti-interference and strong anti-vibration ability, which can meet the protection and monitoring needs of equipment such as feed-line for voltage classes of 10KV and below.The device can be flexibly configured according to the user's requirements to achieve the best performance price.It mainly includes NDW300-L microcomputer line protection monitoring device, NDW300-PD microcomputer capacitor protection monitoring device, NDW300-E microcomputer motor protection monitoring device, NDW300-PT voltage parallel device and NDW300-MBZT standby power source switching device.Through different Settings, it can be applied to line protection (including incoming line, outgoing line), sectional protection, line transformer group protection (including station, used transformer).

NDW300 series microcomputer protection and automatic device has the following characteristics:

  • It has complete protection function and local monitoring function.According to the needs of users, the communication function can be selected to realize the simple and practical integrated monitoring function.
  • High performance, high reliability, high integration of wide temperature military or industrial chip;High-precision resistive and capacitive elements;The sealed relay ensures the reliability of the device under high and low temperature conditions.
  • Fully enclosed anti-interference unit case, new type backplug structure design, double layer shield, no external bus, reduce the influence of electromagnetic interference. 
  • According to the reliability requirement of relay protection, the monitoring system is designed to improve the overall reliability of the system so as to realize the unattended substation.
  • Double-position acquisition is adopted in switch remote signaling to avoid the problem of jitter in switch operation.
  • The device has perfect self-check function, and can lock the outlet reliably when the device is not working normally, so as to ensure the device does not move by mistake.
  • Special clock chip, supported by a single crystal oscillator, with spare battery, the clock can go correctly even after the device is powered down, so that the device can accurately record all kinds of fault information.
  • The RS485 communication interface and CAN communication interface with high-speed magnetic isolation technology are stable and reliable. The RS485 communication adopts modBUS-RTU protocol, which CAN be selected by setting, and CAN communication interface adopts IEC60870-5-104 protocol.
  • The software in the device adopts modular design and has many redundant measures. It has been tested by field operation for a long time, and the program runs stably and reliably.
  • LCD interface in Chinese, multi-layer menu display, rich display information, friendly human-machine interface, no complex training can be completed commissioning work.

Technical parameters

2.1 Rated data

Alternating current
5A、1A 
Ac voltage
100V 
Ac frequency
50 HZ 
Dc voltage
220V , 110V 

2.2 Power consumption

Ac current loop
IN = 5A
No more than 0.5VA per phase
Ac voltage loop
U = UN
No more than 0.2VA per phase
Dc power circuit
The normal work
No more than 8W
protections
Not more than 10W

2.3 Overload capacity

Ac current loop: 2 times rated current
Continuous work
10 times the rated current
Allowed to work for 10 seconds
40 times the rated current
Allowed to work for 1S
Ac voltage loop: 1.2 times rated voltage
Continuous work
Dc power supply circuit: 80% ~ 110% rated voltage continuous operation

2.4 Measurement Error

current
No more than plus or minus 0.5%
voltage
No more than plus or minus 0.3%
power
Not greater than ±1.0 %

2.5 Temperature influence

The variation of operating value caused by temperature change in the normal operating temperature range from -10℃ to 55℃ is no more than ± 1%

2.6 Permitted environmental conditions

Normal operating temperature
-10℃~55℃
Relative humidity
45%~90%
The atmospheric pressure
From 80 to 110 kpa

2.7 Anti-interference performance

⑴ pulse interference test
It can withstand the attenuation shock wave pulse interference test with the voltage amplitude of 1MHZ and 100KHZ at a common mode of 2500V and differential mode of 1000V. 

⑵ The electrostatic discharge reactance test
Can withstand the Ⅳ IEC61000-4-2 standard, test voltage 8 kv static contact discharge test. 

⑶ Radiofrequency electromagnetic field radiation immunity test
Can withstand the IEC61000-4-3 standard Ⅲ, interference field strength 10 v/M of radiation electromagnetic field interference test. 

⑷ Electrical fast transient pulse group immunity test

⑸ Surge (impact) disturbance resistance test
Can withstand the IEC61000-4-5 standard Ⅳ, open circuit test voltage level 4 kv surge interference test 

⑹ power supply system and connected equipment harmonic, harmonic wave interference test
Can meet the IEC61000-4-7 standard B class, current and voltage of the maximum allowable error not more than 5% of the measured value.

⑺ For power voltage sag, short - term interruption and voltage variation
Can withstand iEC61000-4-11 standard 70% UT class voltage sag, short - time interrupt interference test. 

⑻ Therefore, oscillation wave immunity test
Can withstand the IEC61000-4-12 standard Ⅳ level damped oscillation wave interference test, as well as the common mode voltage amplitude 4 kv, differential mode 2 kv Ⅳ ringing wave interference test.

⑼ Interference resistance of power frequency magnetic field
Can withstand the IEC61000-4-8 standard Ⅳ continuous power frequency magnetic field interference test. 

⑽ We will damp the interference resistance of oscillating magnetic field
Can withstand the IEC61000-4-10 standard Ⅳ level damped oscillation magnetic field interference test.

2.8 Insulation resistance performance

Ac input to ground: greater than 100 megohm
Dc input to ground: greater than 100 megohm
Signal and output contact to ground: greater than 100 megohm
Open entry circuit to ground: greater than 100 megohm
It can withstand 2KV/1min power frequency withstand voltage, 5KV impulse voltage

2.9 Mechanical properties

⑴ vibration
To withstand vibration endurance tests of class I, as specified in 16.3 of GB/T 7261 

⑵ the impact 
To withstand impact endurance tests of class I, as specified in 17.5 of GB/T 7261

⑶ the collision
Capable of withstanding the severity class I specified in Chapter 18 of GB/T 7261

Microcomputer protection terminal diagram

ndw300xiliebaohuzhuangzhi 1Shape and opening dimensions

ndw300xiliebaohuzhuangzhi 01

Message feedback

News Center

> Return to work in the disease

On February 26, the production of NPOWER Group resumed. The director and manager of our company personall...

> Resistance to disease

This year Spring Festival, the sudden outbreak of the new champions league, brought unprecedented challen...