We have discussed with our chief R & D and here are our comments :
- We understand that this kind of construction (metal shielding inside the cable) is very challenging for passing fire test
- We assume that this construction creates a higher stress to the mica insulation (most probably gas emission blocked inside the shielding or immediate higher temperature inside the shielding)
- in order to improve fire insulation performance, we advise to use a high-density mica paper with a very high content of special silicone binder
- specifically we propose to apply 2 layers with 45-47% overlapping of:
option 1: Cablosam 366.21-10 (0.12mm)
option 2: Cablosam 366.19-20 (0.18mm)
Should try both options...as if 366.21-10 fails, there is a good chance to pass with 366.19-20
- for cross-section 1.5 mm2, we advise to apply a width of 7mm
- it is also very important to respect the overlapping of 45% (max 47%)
However, these 2 products are very expensive (US$60/kg for 366.21-10 and US$74/kg for 366.19-20), because of the very high costs of both products (special mica / special resin - very high resin content / high-tech manufacturing process).
We fully understand the very high costs and therefore ask if you would like to ask if you would consider to proceed, which we can arrange some samples for your testing.
Otherwise we do not have other products to offer for this special construction.