Adding leads to passive heat detector

Hello,

I’m looking to add leads to a passive heat detector that comes with 6" leads. The system is composed of thermal-mechanically actuated NO contact “heat detectors” on a 24VDC supervisory system. Each detector is in parallel with the EOL resistor (see image link below). I’m being pushed by my senior engi’s to use a splice box that meets the NEC conductor splicing requirements. The issue is that at this location there is no where to put a box within less than 6" of the device without being an obstruction. I personally don’t see how adding leads via buttsplice/solder w/ shrink wrap to an extremely low current low voltage system would require NEC code compliance so I wanted to get input from experts on Fire Protection installations such as yourselves. My question boils down to: do I need to provide an NEC code complaint splice box to splice extensions to the OEM conductors?

We are installing these heat detectors:
https://kidde-fenwal.com/Public/System_Details/Fenwal-Controls/DETECT-A-FIRE-Fire-and-Overheat-Detectors

Here’s the wiring config: https://i.ibb.co/0GkyBLL/Attach.png

Yes, per NEC you need to have the splice in a junction box or fitting approved for the purpose. If you’re running the wires in pipe, look up conduit body type LR or LL or tee. You can get ones with 1/2" threads that will accept the heat detector. Then make the connection in the fitting.

[quote=pilot post_id=82927 time=1547658486 user_id=4714]

Yes, per NEC you need to have the splice in a junction box or fitting approved for the purpose. If you’re running the wires in pipe, look up conduit body type LR or LL or tee. You can get ones with 1/2" threads that will accept the heat detector. Then make the connection in the fitting.

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Thank you for the reply. The box cubic inches requirement for the 8 conductors to be spliced together will cause issue with the client but I suppose they’ll have to live with it.