Double Power Supplies Wcq2c Automatic Intelligent Type Changeover Switch 50Hz 400V Transfer Switch

It is an automatic transfer switch with a built-in intelligent electronic controller that monitors two power supplies and selects the healthier one without manual intervention. "Intelligent" means it goes beyond simple switching: it checks voltage and frequency, applies programmable delays, indicates faults, and drives a generator start/stop signal. It is rated for 50Hz, 400V-class low-voltage dual-power systems.

The controller continuously measures both source voltages and phase sequence, applies over/under-voltage and under-frequency thresholds, and delays transfers to ignore brief sags. It provides LED or display feedback showing which source is active and what fault occurred (loss of phase, over-voltage, etc.), and it can drive auxiliary outputs such as generator start. These parameters are configurable rather than fixed, adapting the ATS to different site conditions.

In normal operation the load is fed from the main source. If the main voltage collapses or a phase is lost, the controller waits a set fault-detection delay, sends a start signal to the standby generator, waits for it to stabilize, then opens the main contacts and closes the standby contacts. When the main returns and stays within limits for the return delay, the switch transfers back and stops the generator. The mechanical interlock ensures the two sources are never paralleled.

50Hz is the rated mains frequency, and 400V is the rated three-phase low-voltage operating voltage (230V phase-to-neutral). These ratings match standard three-phase distribution in many regions. The device's insulation, contact rating, and controller voltage sensing are designed for this class, so it should be applied only on systems within the stated tolerance bands.

The physical contact operation is fast—typically tens of milliseconds—because the double-throw mechanism is motor or solenoid actuated. The visible interruption time is longer because of deliberate delays: a generator-start delay, a warm-up delay before transferring, and a return delay after the main is restored. These delays are adjustable to prevent frequent source "chatter" and to let the generator reach stable frequency and voltage.

Yes—through auxiliary relay outputs the controller signals the generator set to start when the main fails and to stop once the main is restored and the load has transferred back. This makes the whole backup sequence fully automatic. The user only needs to set the start/stop timing and ensure the generator starter circuit matches the contact rating.

The WCQ2C is offered in 1P, 2P, 3P, and 4P versions so it can serve single-phase or three-phase loads. For a 400V three-phase four-wire installation, a 4P unit switches L1, L2, L3, and N; for a three-phase three-wire load, a 3P unit suffices; single-phase loads use 1P or 2P. Choosing the correct pole count ensures both sources are fully isolated and prevents neutral cross-feed.

Mount the switch on a DIN rail or panel rail in the distribution board; connect the main and standby supplies to their inputs, the load to the common output, and earth the enclosure. A qualified electrician configures the controller (voltage thresholds, delays, generator interlock) and verifies correct phase sequence. Upstream protective devices should be sized to the rated current, and the two source neutrals must not be commoned except as intended by the wiring system.

It is used in homes, villas, offices, retail shops, and small commercial buildings that need automatic backup from a generator or a second feeder. It also serves critical small loads such as lighting, pumps, security, and small HVAC systems where a blackout is unacceptable. The intelligent controller makes it suitable for unattended sites where no operator is on hand to perform a manual transfer.

It is designed to IEC 60947-6-1 for automatic transfer switch equipment. Maintenance consists of periodic simulated transfer tests (disable the main supply and confirm start, transfer, and return), re-torquing terminals, inspecting controller indicators, and keeping the enclosure clean and dry. Record each test; if the unit fails to transfer, alarms repeatedly, or operates slowly, a qualified technician should inspect the contacts and controller. OEM/ODM partners can request custom branding, ratings, and controller parameter sets.