ASD-441H Relay Motor Protection

Description

Overview of Relay Motor Protection

• The  ASD-441H 3-phase Relay Motor Protection is primarily designed to protect motors.It is suitable for high-voltage motors in 3 kV to 35 kV systems,
  and serves as bay-level equipment, performing protection, measurement, control, and communication functions.

Product Functions (ANSI)

• Instantaneous Overcurrent Protection 50
• Definite Time Overcurrent & Negative Sequence Overcurrent Protection 51 / 46
• Inverse Time Overcurrent & Inverse Time Negative Sequence Current Protection 51 / 46
• Negative Phase Sequence Voltage Protection 47
• Locked Rotor Protection: Start Locked Rotor & Running Locked Rotor Protection 48
• Thermal Overload Protection 49
• Undervoltage Protection 27
• Overload Protection 51 / 49
• Zero-sequence Overcurrent Protection 50N / 51N
• Overvoltage Protection 59
• Long Start Time Protection / Start Supervision 66
• VT & CT Disconnection Supervision 60
• Control Circuit Break Monitoring 74

Communication Mode

• Optional: RS-485, CAN bus, Ethernet, IEC 60870-5-103 (IEC-103)

Relay Motor Protection Wiring Diagram

 

Setting Table

No.	Description	Setting Range	Conversion Factor for Upload & Download
1	Control Word 1	0000～FFFF	–
2	Control Word 2	0000～FFFF	–
3	Control Word 3	0000～FFFF	–
4	Running Stall Time (Running Stall Delay)	0.00～120.00s	×100
5	Starting Stall Time (Starting Stall Delay)	0.00～120.00s	×100
6	Instantaneous Overcurrent Delay	0.00～120.00s	×100
7	Negative Sequence Instantaneous Delay	0.00～120.00s	×100
8	Phase Sequence Reversal Voltage Delay	1.00～100.00s	×100
9	Under-voltage Protection Delay	0.00～120.00s	×100
10	Zero-sequence Overcurrent Delay	0.00～120.00s	×100
11	Overload Delay	0.00～120.00s	×100
12	Start Delay	0.00～120.00s	×100
13	Over-voltage Delay	0.00～120.00s	×100
14	Running Stall Current Setting	0.04～99.99A / 0.10～20.00A	×100
15	Starting Stall Current Setting	0.04～99.99A / 0.10～20.00A	×100
16	Instantaneous Overcurrent Setting (During Start-up)	0.04～99.99A / 0.10～20.00A	×100
17	Inverse-time Overcurrent Setting	0.50～10.00A / 0.20～2.00A	×100
18	Negative Sequence Instantaneous Current Setting	0.04～99.99A / 0.10～20.00A	×100
19	Negative Sequence Inverse-time Current Setting	0.50～10.00A / 0.20～2.00A	×100
20	Spare Setting (Original Start Setting)	–	×1
21	Zero-sequence Overcurrent Setting	0.02～5.00A / 0.50～99.00A	×100
22	Current Presence Setting	0.20～5.00A	×100
23	Overload Current Setting	0.04～99.99A / 0.10～20.00A	×100
24	Rated Current (Long-term Allowable Current of Motor)	1.00～5.00A	×100
25	τ1 (Time Constant for Inverse-time Overcurrent)	1.00～100.00s	×100
26	τ2 (Time Constant for Negative Sequence Inverse-time)	1.00～100.00s	×100
27	Thermal Protection (Thermal Time Constant)	1.00～100.00s	×100
28	Thermal Alarm Coefficient	0.01～0.08	×100
29	Under-voltage Protection Setting	5.00～100.00V	×100
30	Over-voltage Setting	5.00～100.00V	×100
31	Running Instantaneous Current Setting	0.04～99.99A / 0.10～20.00A	×100
32	Overcurrent Setting	0.04～99.99A / 0.10～20.00A	×100
33	Overcurrent Delay	1.00～100.00s	×100
34	Current Blocking Setting (Blocking Value for Over/Under-voltage Protection)	0.04～99.99A / 0.10～20.00A	×100
35	External Auto-start Delay	0.100～655.350s	×100
36~48	Reserved	–	–

Outline and Installation Dimensions

   

FAQ

Q：Relay Motor Protection is primarily designed to protect motors, so how should one choose one?

A:There are many types of motor protection relays, and several principles should be considered when selecting one.

First, motors are classified by voltage rating into low-voltage and high-voltage categories; different voltage ratings require different selection methods.

Second, consider the motor’s capacity; generally, motors with higher capacity have more stringent technical requirements.

Third, refer to the project’s technical specifications.

Q: What is Relay Motor Protection?

A: It refers to protective relays specially designed to monitor motors and guard against overload, short circuit and other faults.

Q: What core functions does Relay Motor Protection provide?

A: It mainly offers overcurrent, earth fault and overload protection to keep motors running safely.

Q: Where is Relay Motor Protection commonly used?

A: It is widely applied in industrial plants, power stations and distribution systems to protect various electric motors.

Q: Which motors is this protection suitable for?

A: Applicable to medium & low voltage motors in thermal power plants, water treatment stations, mines, chemical plants and substations; covers 0.4kV, 6kV, 10kV high-voltage large industrial motors including fans, pumps, compressors and belt conveyors.

Q: What is the difference between overload protection and short-circuit protection?

A: Overload protection (51,49) acts with long delay for long-term overloading, only trips after thermal accumulation reaches limit. Short-circuit protection (50) is instantaneous trip with no delay to cut off severe fault current immediately.

Q: Why does the motor protection trip on single-phase running?

A: One phase power loss will generate large negative sequence current, causing severe local overheating of stator winding within minutes. Function 46 detects unbalanced current and executes trip to avoid winding burnout.

Q: What is locked rotor / stall protection?

A: When the motor cannot rotate after energization, rotor current surges to locked rotor value. This protection monitors startup duration and current magnitude; it trips if startup exceeds preset time to prevent winding overheat.

Q: What signals need to be connected to the relay?

A: Three-phase CT current signals, PT voltage signals, breaker position auxiliary contacts, trip circuit wiring, DC control power supply, remote alarm signal terminals.

Q: What auxiliary power does the motor protection relay need?

A: Main control power is DC110V / DC220V for tripping loop; AC220V for device operation, communication and cabinet dehumidification.

Q: What communication protocols are supported?

A: Standard: Modbus-RTU, Modbus-TCP, IEC 60870-5-103, IEC 104; IEC 61850 GOOSE/MMS is optional for smart power station.

Q: Can fault records be uploaded to SCADA?

A: Yes. The relay stores fault event records, fault type, action element, fault waveform and trip time, which can be uploaded to the background monitoring system for troubleshooting.

Q: Protection gives false tripping during normal motor operation

A: Common causes: CT wiring loose or reversed, incorrect protection setting value, severe grid voltage fluctuation, strong electromagnetic interference, damaged current transformer. Check secondary circuit first then verify parameter settings.

Q: Can we temporarily disable part of protection functions?

A12: Individual protection elements can be enabled or disabled via password authority on the relay panel. It is not recommended to disable core protection such as short circuit and earth fault for long-term operation.

Q: Can the relay be replaced separately without changing the whole cabinet?

A: Yes. The protection relay adopts modular design with unified terminal definition, allowing single unit disassembly, replacement and commissioning without modifying the entire cabinet wiring.

Q: Which industry standards does the product comply with?

A: Complies with IEC 60255, IEEE ANSI C37 series, relevant GB/T standards for power system relay protection.

Q: Is customized function expansion available?

A: Support adding insulation monitoring, bearing temperature access, vibration signal interlock, dual backup protection and interlock logic with upstream switchgear according to on-site one-line diagram.

Q: What documents are provided upon delivery?

A: Schematic drawing, terminal wiring diagram, relay operation manual, setting instruction, factory test report and equipment bill of materials.

Q: What is the standard warranty period?

A: 24 months warranty from factory shipment date; on-site commissioning and extended warranty service are available on request.