Scope of Application

HSLQ3 Automatic Transfer Switching Equipment (ATSE) integrates switching unit and logic control into one single unit without an external controller, realizing full mechatronic integration. It is equipped with functions including voltage detection, frequency detection, communication interface, electrical interlock and mechanical interlock, supporting automatic control, remote motorized control and emergency manual operation.

All operations are executed by the logic control board, which drives the motor and gearbox via preset logic commands. The motor charges the switch’s energy-storage spring; the instant-release acceleration mechanism rapidly makes, breaks or transfers circuits, while visible mechanical position ensures safe isolation to greatly enhance electrical and mechanical performance.

The HSLQ3 features compact and robust all-metal overall housing: the control section adopts metal enclosure, whereas the switching section’s housing is made of glass fiber unsaturated polyester resin with excellent dielectric property, high protection grade and reliable operational safety.

This switch is designed for automatic transfer and safe isolation between main & standby power sources in power supply systems, or between two sets of load equipment.

With elegant, innovative and compact outline plus comprehensive functions, it stands as an optimal option among similar products.

The full HSLQ3 series has passed EMC (Electromagnetic Compatibility) testing.

Model Definition

Type Selection Example

HSLQ3‑100/4‑Ⅲ‑380V In50A Automatic Transfer Switch Conventional thermal current: 100A; AC rated voltage: 380V; rated operational current: 50A; 4-pole (3 main poles plus make-break neutral pole). Designed for auto-switch & auto-revert in mains-to-diesel generator power supply system.

Compliance Standards

The HSLQ3 series Automatic Transfer Switches comply with the below standards:

International Standards

IEC 60947‑1(1998): Low-voltage switchgear and controlgear – Part 1: General rules

IEC 60947‑3(1999): Low-voltage switchgear and controlgear – Switches, disconnectors, switch-disconnectors and fuse-combination units

IEC 60947‑6(1999): Low-voltage switchgear and controlgear – Multiple function equipment, Automatic transfer switching equipment

National Standards (China GB)

GB/T 14048.1‑2002: Low-voltage switchgear and controlgear – General rules

GB 14048.3‑2002: Low-voltage switchgear and controlgear – Switches, disconnectors, switch-disconnectors and fuse-combination units

GB 14048.11‑2002: Low-voltage switchgear and controlgear – Multiple function equipment Part 1: Automatic transfer switching equipment

Main Technical Performance Parameters

Performance & Features

1.Adopts double-row composite contacts, horizontal linkage mechanism, pre-energy-storage micromotor and microelectronic control technology to realize nearly zero arc without arc chute.

2.Equipped with reliable mechanical and electrical interlocks; the actuating component is an independent load disconnector for safe operation.

3.Zero-positioning technology enables forced zero position (cut off both power sources simultaneously) under emergency to meet fire linkage requirements.

4.Single-motor drive for load disconnector switching delivers stable, quiet switching with low impact force.

5.The drive motor only draws current momentarily during switching; no steady-state operating current is required, achieving remarkable energy saving.

6.Built-in mechanical interlock prevents mutual interference between normal and standby power supplies.

7.Visible open-position indicator and padlocking function ensure reliable isolation between power source and loads.

8.Excellent safety, high automation and outstanding reliability with service life over 8,000 operating cycles.

9.Mechatronic integrated design ensures precise, flexible and smooth switching; advanced international logic control features strong anti-interference performance with no external interference.

10.Three stable working positions (I‑0‑II): Normal closed / Standby open; Normal open / Standby closed; Both sources open.

11.Easy installation with plug-type terminals for control circuit wiring.

12.Four available operation modes: Emergency manual operation, remote motorized control, emergency cut-off under automatic mode, fully automatic control.

Product Application

HSLQ3 series automatic transfer switches are applied in 50Hz AC 380V / DC 220V power distribution and motor circuits (rated current:16A~3200A) for automatic switching between normal & standby power, mains and generator sets. It also serves for infrequent circuit make/break and circuit isolation.

Widely used in non-interruptible critical power supply sites including fire-fighting facilities, hospitals, banks and high-rise buildings for power distribution and automatic control systems.

Basic Type: Main-Standby Power, Auto-switch & Auto-revert

Type I: Below 100A: Mains-to-Mains, auto-switch & auto-revert, three-phase phase-loss detection for both sources; Above 125A: Mains-to-Mains, optional main-first or standby-first auto transfer, full three-phase monitoring on both supplies.

Type II: Mains-to-Mains, selectable operation mode (auto-switch & auto-revert / auto-switch no auto-revert), with three-phase phase-loss, overvoltage & undervoltage monitoring for dual power.

Type III: Mains-to-Generator, auto-switch & auto-revert; monitors three-phase phase loss, over/undervoltage for mains plus frequency detection for generator.

Control Features of Basic Type

1.Designed for main-and-standby dual-power system with auto-switch & auto-revert logic.

2.External terminals available for function expansion.

Control Features of Type I

1. Rating ≤100A

A. Applied for dual mains main-standby power system.

B. Upon main circuit fault (power failure / phase loss), the switch transfers to standby supply after adjustable delay (1~16s).

C. When main supply restores normal, the switch reverts back to main circuit after adjustable delay (1~250s).

2. Rating ≥125A

A. Applicable for mains main-standby or mutual backup dual-source system.

B. Auto-switch & Auto-revert Mode (Main-preferred): On main supply fault (blackout/phase loss), switch shifts to standby after 1~16s delay; reverts automatically to main source with adjustable 1~120s delay after main recovery.

C. Auto-switch No Auto-revert Mode (Mutual backup): If Source I fails, switch transfers to Source II after 1~16s delay; it stays on Source II after Source I recovers. Only when Source II fails will the switch switch back to Source I after 1~120s delay.

3.Priority power source can be set via plug-in terminal wiring.

Type II Control Characteristics

1.Suitable for dual-mains main‑standby or mutual backup power systems.

2.Auto-switch & Auto-revert Mode: When a fault (phase loss, over/undervoltage) occurs on the main circuit, the switch transfers to standby supply after adjustable 1~16s delay; after main supply recovers, it reverts back to main circuit with 1~250s adjustable delay.

3.Auto-switch No Auto-revert Mode: If Source I fails (phase loss, over/undervoltage), the switch switches to Source II after 1~16s delay. It remains on Source II after Source I restores, and only switches back to Source I after adjustable 1~250s delay when Source II develops a fault.

4.Priority power source selectable via plug terminals (for ratings above 125A).

Type III Control Characteristics

1.Designed for system with mains as main supply and diesel generator as standby supply.

2.Upon mains fault, the controller sends generator start signal first; after fixed 3s delay the switch goes to neutral “O” position, then automatically switches to generator circuit after adjustable warm-up delay (1~250s).

3.When mains recovers, the switch reverts to mains after 1~250s adjustable delay; after another 1~250s delay the controller outputs generator stop signal.

4.Equipped with phase-loss, over/undervoltage monitoring for both mains and generator plus generator frequency detection.

Common functions for all four types above

① Automatic, remote and manual control functions.

② 0.5s signal delay detection to avoid false operation.

③ Remote control to neutral “O” position under automatic mode.

④ Key-operated selector switch for mode selection.

⑤ Optional RS‑485 communication interface configured on customer request.

Service Conditions

1.Altitude shall not exceed 2000 meters above sea level.

2.Ambient temperature: −5℃ ~ +40℃; relative humidity ≤95%.

3.Free of explosive hazardous atmosphere.

4.Protected against rain and snow ingress.

Note: If the equipment is intended for operation at ambient temperatures above +40℃ or within −45℃ ~ −5℃, the user shall notify the manufacturer in advance.

HSLQ3‑1600A Automatic Transfer Switch Outline Dimension Drawing

HSLQ3‑800~3200A Basic Type Automatic Transfer Switch