Apollo Fire Alarm Interface Unit, Intelligent DIN-Rail Input/Output, 1A Relay SA4700-302APO

What this interface does

An interface connects a fire alarm loop to equipment that does not speak the panel's language. It is how a panel can read a plain switch contact and can switch something else in response.

This Apollo unit does both jobs in a small body made for a DIN-rail inside an enclosure.

How it works

• Input side: volt free means the contact carries no voltage of its own. The unit supervises one or more normally open contacts, wired on a single pair of cables.
• Output side: the relay gives changeover contacts, marked NO, COM and NC on the unit. These are switched as the panel commands.
• Failsafe: in this mode the relay activates by itself on loss of loop or protocol loss. The unit reports it to the panel with an analogue value of 17.
• Device behaviour: on XP95 and Discovery it behaves as an XP95 device. On CoreProtocol it behaves as a Soteria device.

Where to use it

Typical jobs include taking a signal from a sprinkler flow switch, or telling plant to shut down when the alarm operates. The system design decides what is connected.

It belongs inside an enclosure. It is not designed for outdoor use unless it is mounted in a suitable weatherproof enclosure.

Where it releases doors held by electric locks, agree the arrangement with whoever holds the fire strategy.

What the figures mean in practice

• 1 A at 30 V: this is a low voltage contact, so it cannot switch a mains load directly. Use an interposing relay for that, sized for the load.
• Current draw: the quiescent figure is 500 µA, rising to a maximum of 3.5 mA with LEDs on. Use these figures in your loop calculation, and allow for the 900 µA surge at power-up.
• Temperature: the range of – 40°C to + 70°C is wider than most indoor panel locations will ever see, but the no condensation or icing condition still applies.

Installing it

• Instructions: Apollo's Installation Guide 39215-160 holds the installation steps.
• DIL switch: the switch selects Failsafe mode, and mode 1 is DIL Switch XP Mode. Check the guide for the settings on your panel.
• Reading the LEDs: a flashing green Poll/ISO LED is the polling LED. Continuous yellow on RLY or I/P shows a relay fault or an input fault.

Planning your system

You will need a compatible control panel, a suitable enclosure with a 35 mm rail, and the contacts or equipment being connected. Features are fire control panel dependant, so confirm them first.

The controllable isolator, the address range and the nine modes are for CoreProtocol enabled systems only. Do not plan on them with an XP95 or Discovery panel.

Standards and ratings explained

• EN 54-17 and EN 54-18: the EN standards for short-circuit isolators and for input/output devices on fire systems.
• BS 7273-4: the standard on actuating door release mechanisms from a fire system. Failsafe Mode meets its requirements, and the wider door arrangement still has to be designed to it.