Description
GATS-A02 2P Automatic Transfer Switch with L1/L2/L3 Phase Selection and Adjustable V/A Protection
The GATS-A02 is a DIN-rail automatic transfer switch that watches three incoming lines (L1, L2, L3) and keeps a single-phase 2P load supplied from whichever line is within limits. It is offered in 63A, 80A and 100A for AC 220V or AC 110V systems, and combines phase priority, over-voltage and under-voltage protection, current protection, and automatic reconnection in one housing. A four-window display shows the three line voltages together with the load current, and a Fault indicator flags the reason for the last operation. Thresholds are user-adjustable: on the 220V version over-voltage can be set from 230V to 300V and under-voltage from 140V to 220V, with 270V and 170V pre-set at the factory.
Size Dimensions
Working Principle
The three input lines are candidate sources, not three phases carried at once. The microcontroller measures L1, L2 and L3 continuously against the stored voltage window and connects one of them to the output, which is why the 63A / 80A / 100A rating applies to the single-phase path. Normally the load runs on the line chosen as priority phase (L1 by default, or Auto). If that line exceeds the over-voltage setting or falls below the under-voltage setting, the switch releases it and moves the load to a reserve phase in less than 0.2s, so the load keeps running as long as one line stays inside the window. Trip timing is graded by the measured voltage: below 350V the unit acts within 0.1s, and above 350V it acts within 0.02s — useful when a broken neutral pushes the line voltage onto the load. When the priority phase returns and holds steady through the return delay (1–600s), the unit transfers back on its own, and a 5V hysteresis band keeps it from chattering when the voltage sits close to a threshold.
Key Features
- Automatic transfer — line changeover runs without operator action.
- Priority phase — the preferred line is defined and resumed once it is healthy again.
- Adjustable V/A settings — voltage and current thresholds are entered on the unit, so the same model suits weak grids and stable grids alike.
- Auto reconnect — self-resetting after the fault condition clears; no manual reset required.
- 4-window display — L1, L2, L3 voltage and load current readable at a glance, plus Fault indication.
- Button colour — blue button as standard, grey button available on request.
Protection Functions and Setting Values
Because the display models are digitally adjustable, the setting ranges are deliberately wide; the factory defaults are the values most projects run with:
- Over-voltage — 220V version 230–300V (default 270V); 110V version 110–300V (default 140V).
- Under-voltage — 220V version 140–220V (default 170V); 110V version 80–220V (default 90V).
- Current protection — threshold adjustable within the rating of the selected model (63A / 80A / 100A).
- Note — any value inside the ranges above can be programmed on the unit; the defaults apply only to units shipped without a special request.
Installation
- Clip onto a standard 35mm DIN rail in a distribution board or enclosure.
- Bring L1, L2, L3 and N to the marked input terminals; take the 2P output to the load. Follow the front-panel markings exactly.
- De-energise before wiring, and torque the terminal screws so conductors cannot work loose — this matters most on the 80A and 100A versions.
- Power up and check that the three voltage windows show plausible readings before switching the load on.
- Confirm or re-enter the voltage and current settings during commissioning, then record them in the board documentation.
Typical Applications
Apartment blocks and multi-unit residential boards fed from a three-phase riser, shops and small offices, telecom and monitoring cabinets, pump and irrigation control, lighting circuits, and any single-phase load in an area where one line often sags or swells while the other lines stay usable.
