Automatic power switch with measurement and communication, 4P 1250A HIC491E

Automatic power transfer switch with measurement and communication

This device functions as a reverse transfer switch between two power sources – the grid and a generator – with automatic switching under load. It does not provide continuous power (it is not a UPS system), but enables safe and controlled switching during a brief power interruption. It also allows manual operation via an unlinked lever‑type emergency mechanism.

It has an integrated motor drive that performs the switching without manual intervention. It includes a locking mechanism that allows the position to be physically secured – e.g., during service work or to prevent unauthorized switching. A hanging lock can also be applied.

Construction and installation

The device is designed for mounting in distribution panels – it is not suitable for front mounting or DIN rail installation. It has a fixed construction (festeinbau) and is permanently mounted inside a cabinet. The main connections are cable‑clamp type, meaning conductors are connected directly to terminals rather than via busbars. Dimensions and mounting method are matched to standard 4‑hole distribution panels, although there is no special bracket for central mounting.

Functionality and safety

It is classified as a main disconnect, safety disconnect, and maintenance disconnect – thus meeting requirements for circuit isolation from voltage during servicing. It has 4 poles and operates at 380–415 V AC. Continuous current rating is 1250 A, and short‑circuit withstand capability is 64 kA (Icw) under short‑time duty. The rated conditional short‑circuit current (Iq) is 100 kA – meaning it can safely interrupt a maximum short circuit when protected by appropriate gl‑gG fuses.

The making capacity at 400 V is 822 kW – allowing safe make‑and‑break of loads up to this power during normal operation. Rated operational power for AC-23 (motors) is 562 kW.

It has one normally closed auxiliary contact – used to signal the switch position (e.g., “grid active” or “generator active”) to an EMS or SCADA system. No other auxiliary contacts – there are no change‑over or auxiliary switching contacts.

Communication and energy measurement are built in – the device can transmit data on power status, current, voltage, and switch position to monitoring systems. This is a key feature for installations requiring energy monitoring or building automation.

IP00 protection rating indicates no protection against touch or dust – the device must be enclosed in a distribution cabinet. No NEMA classification.

It is not an emergency stop switch – it is not intended for immediate circuit disconnection in life‑threatening situations.