The Thorn MK2 125-065-878 (125-585-128) is a line isolator module used in Thorn/Minerva fire detection systems. It is designed to isolate a section of the fire alarm detection loop in the event of a short circuit, helping maintain operation of the remaining devices on the loop. The exact identification is 125-065-878, with assembly number 125-585-128.
Key Features
- Short-circuit isolation for fire detection loop sections.
- Helps prevent a fault on one section from disabling the complete detection circuit.
- Designed for Thorn Security / Minerva fire alarm systems.
- Compact PCB-based module suitable for system-panel installation.
- MK2 version with multiple documented PCB revisions.
- Lightweight construction, approximately 50 g.
- Suitable for marine and industrial fire detection installations.
- Used as a replacement/spare for existing LI520 MK2 modules.
Typical Applications
- Marine vessel fire alarm systems.
- Offshore platforms and installations.
- Thorn/Minerva analogue-addressable fire detection systems.
- Industrial fire alarm panels.
- Shipboard accommodation and machinery-space detection loops.
- Fire detection loop segmentation and fault isolation.
- Replacement of legacy Thorn LI520 MK2 line isolator modules.
