2CDE160010R0901 ABB E452-5.7A Electronic Priority Switch

Why Choose the ABB E452-5.7A Priority Switch?

The ABB E452-5.7A is an electronic priority switch / load-shedding relay designed for installations where the available supply capacity or conductor sizing does not permit two high-power electrical loads to operate simultaneously. Part of ABB's E450 priority switch range, it automatically gives priority to a selected short-term load while temporarily disconnecting a lower-priority long-term load.

The E452-5.7A monitors the current drawn by the priority load through a current coil connected in series with that consumer. When the monitored load is switched on and the operating threshold is reached, the device opens its normally closed output contact, which can be used to release a contactor controlling the lower-priority load. When demand from the priority consumer ends, the lower-priority circuit can be restored automatically.

With a 7–39 A measuring range, 230 V AC rated voltage, 43 A continuous operating current and a compact single-module DIN-rail format, the E452-5.7A provides a practical solution for automatic load management in residential, commercial and building-services installations.

Key Advantages

• Automatic priority control and load shedding between high-power consumers.
• Helps prevent simultaneous operation of loads that could exceed the available electrical supply capacity.
• 7–39 A measuring range for monitoring the priority consumer.
• 43 A continuous operating current through the monitoring circuit.
• Normally closed output contact for controlling a load contactor.
• Automatic operation eliminates the need for manual load selection.
• Compact single-module DIN-rail design for distribution-board installation.

Key Features

• ABB E450 priority switch series.
• Electronic priority switch / load-shedding relay.
• 7–39 A measuring range.
• 230 V AC rated voltage.
• 43 A continuous operating current.
• 1 normally closed (1NC) contact.
• 400 V maximum switching voltage.
• 230 W maximum switching power.
• 2.4 W power loss.
• Maximum switch-off delay of 20 ms.
• IP40 degree of protection.
• One-module width for compact DIN-rail installation.

Automatic Priority Control for High-Power Loads

Priority switches are particularly useful where two powerful consumers cannot operate simultaneously without exceeding the capacity of the electrical installation. A common example is an installation containing a long-duration load such as storage heating and a short-duration priority load such as an instantaneous water heater. The E452-5.7A detects operation of the priority consumer and uses its normally closed contact to interrupt the control circuit of the lower-priority load.

Once demand from the priority consumer ends, the controlled load can be made available again without manual intervention. This automatic load-management approach can help an installation operate within the available supply capacity without requiring both high-power consumers to be permanently supplied at the same time.

Typical Applications

• Priority control between two high-power electrical loads.
• Instantaneous water heater and storage-heating installations.
• Automatic electrical load shedding.
• Residential electrical distribution boards.
• Commercial and building-services electrical systems.
• Installations with restricted supply or conductor capacity.