What wiring do i need?

[zorber]

I have had fitted Solar thermal heating. Unfortunately instead of extending the controls to the landing they have left them in the attic, this means i cant see what temperature the boil has warmed too or even switch off the system with out going to the attic.. They have used a Grundfos UPM3 HYBRID pump which connects to the controller i wish to move. The 3 core power is easy to understand and extend however there is also a a signal cable (described as this in the instruction Signal cable, FCI, 3 wire, with return) https://www.navitron.org.uk/pwm-pulse-width-modulation-cable-for-upm3-high-efficiency-pumps-and-pumpstations?gclid=EAIaIQobChMIg6KVq5Kf7wIVxO3tCh2i1wfIEAQYASABEgIBWfD_BwE This is the wire i dont understand. What is the correct cable i need to purchase to extend my signal cable? 
signal,

 

[Geoff1946]

That is clearly a special made up to suit the equipment. I wouldn't alter it without checking first with the supplier. They may provide a longer one, or an extension.

It's also possible that the permissible length is limited.

Don't forget that if you alter the installation you will invalidate any warranty which may apply.

 

[SPECIAL LOCATION]

I have had fitted Solar thermal heating. Unfortunately instead of extending the controls to the landing they have left them in the attic, this means i cant see what temperature the boil has warmed too or even switch off the system with out going to the attic.. 

I would get the installer back to rectify the situation, as it sounds a though they have haven't left you with a system that meets your needs..?

OR....   didn't you actually agree what was needed before they undertook the work?

:coffee