Low Voltage Protection Device

• Customization: Available
• After-sales Service: Two Years
• Warranty: Two Years
• Model NO.: LON521T
• Trademark: Linkelec
• Origin: Made in China
• HS Code: 90283012
• Production Capacity: 10000 Per Month

Product Description

Intelligent low-voltage voltage protection measurement and control device

1.Product profile
The intelligent low-voltage protection and measurement device is a new generation of protection and measurement device developed by our company for various fault characteristics of low-voltage MCC circuit motors. It is suitable for AC380V and AC660V low-voltage systems and is mainly divided into LON521D low-voltage motor protection and measurement device, LON521L low-voltage line protection and measurement device, and LON521T low-voltage PT protection and measurement device. It is a low-voltage protection and measurement device with extremely high cost-effectiveness, stability and reliability, integrating relay protection, measurement, control, and communication. The protection measurement and control device collects data such as three-phase current, three-phase phase voltage, line voltage, grounding current, etc. These data are calculated and compared with various protection function setting information recorded by the device. When the protection action conditions are met, the relay output is driven to achieve reliable protection of the motor.
The intelligent low-voltage protection measurement and control device consists of two parts: the protection measurement and control device host and the MCT current transformer. It can achieve measurement function, protection function, motor start/stop control function, and remote communication function. Using RS485 communication function as an important means of remote management, supporting MODBUS-RTU communication protocol.

2.Product specifications

performance parameters	performance indicators
Auxiliary operating power supply	AC/DC85~265V (AC/DC universal wide range)
with the voltage system	AC380V, AC660V (50HZ or 60HZ, labeled as AC380V/100V via PT,
	AC660V/100V)
Power consumption	≤8W during normal operation, ≤12W during protection activation
protector current specifications	25A (Trial motor current range (6.3A~25A))		Select 400A and the following current specifications of the protector (except the frame circuit breaker circuit), the main circuit three-phase cable in the same direction through the protector supporting the corresponding specifications of the current transformer LY-MCT A, B, C three-phase holes, do not need to be equipped with a separate current transformer, the main circuit of the three-phase cable in the same direction through the corresponding specifications of the protector LY-MCT hole
	100A (Trial motor current range (25A~100A))
	200A (Trial motor current range (80A~200A))
	400A (Trial motor current range (160A~400A))
	XXA/5A (Trial motor current range:		When selecting a protector with a current specification of 400A or above, the three-phase line of the main circuit is passed once through three external protection type current transformers with a CT of XXA/5A, and the 5A current line on the secondary side of the three CTs is passed in the same direction, one turn, through the protection LY-MCT, which is used for the protection of the LY-MCT
relay output contacts	3 relay outputs	Relay contact capacity: AC250V/5A
environmental conditions	Operating Temperature	-25ºC~+55ºC
	relative humidity	5% to 90% non-condensing
	Elevation	≤2500m
electromagnetic compatibility	electrostatic discharge test	IEC 1000-4-2 severity class 3
	Radiated electromagnetic field interference testing	IEC 1000-4-3 severity class 3
	fast transient interference testing	IEC 1000-4-4 Severity Class 3
	Surge testing	IEC 1000-4-5 severity class 3

3.Selection specifications  

function point	function point descriptions	LON521D	LON521L	LON521T
protection functions	Initiate timeout protection	√	-	-
	overload protection, overcurrent blocking protection, short circuit protection	√	-	-
	current imbalance protection, phase break protection	√	-	-
	ground fault synthesis computational protection	√	√	-
	Leakage protection / ground fault real pick protection (need to be equipped with zero sequence current transformer / grounding current transformer)	○	○	-
		(choose one or the other)	(choose one or the other)
	underload protection	√	-	-
	overflow fault (fault current exceeding the breaking capacity of the contactor) trips the circuit breaker	√	-	-
	Overvoltage protection, undervoltage protection	√	√	-
	frequency protection, under power factor protection	√	-	-
	Anti-Shake/Shake Restart	○	-	-
	External interlocks	√	√	-
	tE time protection	√	-	-
	Electrical current interruption protection (low voltage blocking overcurrent section)	-	√	-
	Current-limited quick disconnect protection (low voltage blocking overcurrent II)	-	√	-
	Overcurrent protection (three stages of overcurrent)	-	√	-
	Overload protection	-	√	-
	Spring not storing energy alarm	-	√	-
	PT disconnection alarm	-	√	-
	PT disconnection protection	-	-	√
	Low-voltage one-, two- and three-phase protection (can be associated with PT disconnection, switching 1 blocking function)	-	-	√
	busbar overvoltage protection, zero sequence overvoltage protection	-	-	√
	Switching quantity 1 protection	-	-	√
	Switching 2 protection	-	-	√
real-time measurements	three-phase currents, grounding currents, three-phase current unbalance ratio	√	√	-
	Leakage current/grounding actual pickup current	○	○	-
	three-phase phase voltage, three-phase line voltage, frequency	√	√	√
	power factor, active power, reactive power, active energy, reactive energy	√	√	-
	zero sequence voltage, positive sequence voltage, negative sequence voltage	-	√	√
Fault logging	with 32 SOE recordings with 1s resolution	√	√	√
switching inputs	With 6-way DI, built-in power supply, external passive trunk node	√	√	√
Relay Output	With 3-way DO, AC 250/5A; DC 30V/5A	√	√	√
analog output	Optional 1-channel DC4~20mA analog variable output	√	√	√
digital communications	1 RS485 interface, support MODBUS-RTU protocol	√	√	√
undervoltage restart	With the voltage detection function module can realize the short-time under and voltage loss restart function	√	-	-
protection parameter settings	All kinds of protection fixed value query, adjusting	√	√	√
system parameterization	Parameterization of rated voltage, rated current, and communication address	√	√	√
LED indication	start, run, alarm/action, stop	√	√	√
Note: "-" indicates that this function is not available, "○" indicates that this function is optional, and "√" indicates that this function is standard

4.Product installation and schematic diagram

5.Solution

6.About our service           
*  We could provide 7* 24-hour phone call after-sales service. 
*  We provide a 2-year guarantee time and will change the meter for you within 1 year if there's something wrong with the product. Except for natural disasters or man-made reasons.
*  Recommend the most advanced application technology and management model in the industry to customers, and provide customers with detailed solutions.

7.Package and ship