Is the STR-421 signal secure when transmitted over Category 5e UTP twisted-pair cable?

Hello,

I’d like to ask for your opinion on whether it would be safe to send a control signal (approx. 2 s) via a Cat 5e UTP twisted-pair cable: from the doorbell switch to the STR-421 (two-button: http://www.fif.com.pl/pub/File/download/INSTR...ers/FF%20STR-421%20230V%20A080526%20pdf.pdf)?

I’m thinking of shorting it to earth (<1mA), twisted pair cable length: approx. 5 mb.

The roller shutter motors (Somfy) are 230V, the STR-421 controllers are 230V, and within 5 metres of the distribution board there are junction boxes with twisted-pair cable for controlling the blinds; the plan to use RM85 relays has changed – there isn’t enough space in the cabinet for the RM85s now...

P.S. Perhaps twisting two pairs of twisted-pair cable would ensure it can safely carry a transient current of max. 170V | 1mA? Does anyone have experience with this – is anyone using such a solution?

Hello

tomek_k123 wrote:

P.S. Perhaps twisting two pairs of twisted-pair cable would ensure it’s safe to run a brief current of up to 170V | 1mA through it? Perhaps someone has experience with this – is anyone using such a solution?

No one in their right mind would use such a solution, as it’s not just about the current-carrying capacity here, but also the voltage for which the cable is designed (insulation resistance). I’ve already asked a rhetorical question on a similar matter before. Do you think the wide variety of cables available on the market is driven by manufacturers’ desire for profit?
Best regards
pm001

Could you please advise which are the narrowest miniature relays for a DIN rail mount – with a 12V coil – that can switch a current of 1mA and a voltage of 230V?

This control system has been working for 10 years now, and nothing’s gone wrong. There are fuses just in case...

QUESTION: Some of them have already failed; the thermal imaging camera shows that they’re warm (the ones that have failed) – their temperature is clearly higher than that of the neighbouring ones. Has anyone taken apart and repaired an F&F STR-421?