The A51E is an addressable relay providing double pole, volt free, change-over contacts, rated to switch local mains supplies. The unit is intended for installation within the equipment to be switched, thereby offering savings in installation costs when compared to long, auxiliary circuit, wiring runs out from the control panel. Certified to EN54-18, the relay can be located anywhere on the two core ZP loop and is designed for power up or shut down of the mains electrical supply to ancillary equipment. The unit is ideal for the control of associated system equipment such as mains fed magnetic door release circuits, extract fans and dampers.

The relay can be programmed to be activated by any single device, groups of devices or all system devices. All types of system input signals can be arranged to operate the A51E, which can include control panel indicators, zonal outputs, call points or detectors. Both normally closed relay connections (opening on alarm), and normally open relay connections (closing on alarm) are provided.

Housed in a low profile moulding, the relay is designed to clip directly onto a standard DIN 35 mounting rail or equipment panel chassis. Alternatively the relay can be installed in a SMB-DIN1 box (one unit capacity) or SMB-DIN2 box (two unit capacity) – care should be taken to prohibit casual entry into the enclosure.

Installed as part of an analogue addressable system, up to 127 line devices (detectors, call points or interface units) can be connected to each of the control panel loops. All loop devices incorporate switch settings enabling them to be assigned a unique address which is polled by the panel every two seconds.

A red LED indicator positioned on the front moulding flashes when the interface contacts have activated. For system test and commissioning the relay contacts can be operated manually, enabling control circuits to be tested.