Apollo Isolator Base for Isolator 55000-720, XP95 and Discovery 45681-211APO

What this isolator base does

An isolator protects part of a fire alarm loop when the wiring shorts out. This base is the fixed part that holds the Apollo isolator and takes the loop cables.

It looks much like a detector base, but it has a different job. The isolator and this base work as a matched pair.

How it works

• During a fault: isolators sit at intervals on the loop, and only the section between two of them drops out. The rest of the loop stays in service.
• After a fault: there is nothing to reset by hand. Power and data return to the isolated section once the short has gone.

What the figures mean in practice

• Spacing: the limit of 20 detectors (or equivalent) sets how far apart the isolators can be. Some devices may count as more than one, so check each device's own data.
• Joint figures: these figures cover the isolator and base together. Use those current figures when you add the pair to a loop calculation.

Installing it

• Pairing: fit one base for each isolator position, then fit the isolator to it.
• Conditions: keep it away from condensation and icing, which the humidity rating rules out.

Planning your system

Decide the isolator positions at the design stage, since they depend on how many devices lie between them. Your panel maker's loop software normally checks this.

The system also needs Apollo isolators, part 55000-720, and an addressable panel using one of the three protocols. A protocol is the digital language a panel and its devices must share.

Standards explained

• LPCB: the Loss Prevention Certification Board, an independent body that certifies fire and security products.
• This part: Part 45681-211 has LPCB approval only.
• EMC Directive 2014/30/EU: rules that limit electrical interference. The pair complies provided it is used as the maker describes.