Does 14 CFR 25.1310 apply to hydraulic systems? I'm struggling to understand if this particular rule was intended to apply to Electrical Power Generation Systems only or if this rule was also intended to apply to Hydraulic Power Generation Systems.

At first glance I assumed only electrical power generation systems would be applicable.  Then when I go to the EASA AMC for 25.1310 which reads the same it says the following:


  "When alternative or multiplication of systems and equipment is
  provided to meet the requirements of CS 25.1310(a), the segregation
  between circuits should be such as to minimize the risk of a single
  occurrence causing multiple failures of circuits or power supplies of
  the system concerned.  For example, electrical cable bundles or groups
  of hydraulic pipes should be so segregated as to prevent damage to the
  main and alternative systems and power suppliers."


So EASA puts the words "hydraulic tubes" in as part of their example.

Is there some other guidance material out their that would clarify if the reg really applies to 25.1310?
Usually this link below can be very helpful in finding guidance for a particular regulation (e.g. 25.1310). In this case there isn't any guidance for 25.1310.

https://www.faa.gov/aircraft/air_cert/design_approvals/transport/rules_acs_policy/

Next try the preamble for when this regulation was passed or introduced and see if the FAA provided any guidance on their intent for the regulation. The FAA discussed an EWIS (Electrical Wiring Interconnect System) accident which only confuses the intent. However I briefly perused the preamble.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFinalRule.nsf/0/81B77634BED9EAA78625738E007123B3?OpenDocument&amp;Highlight=amdt.%2025-123

25.1310 is in Part 25 Subpart F and most of these regulations (e.g. 25.1309) apply to all systems (e.g. hydraulic, electrical, pneumatic, etc.). Best of luck I hope this helps.