The Multitel FCCP Box complies with TPL-001-5 event category P5 contingencies by detecting and reporting to the control center both low voltage & open circuit in single DC supply reserve battery
FERC approved Reliability standard TPL-001-5 Transmission System Planning Performance Requirements submitted by NERC.
TPL-001-5 sets performance requirements to develop a Bulk Electric System that will operate reliably over a broad spectrum of system conditions covering a wide range of probable contingencies.
TPL-001-5 addresses several scenarios from P0 to P7. Scenario P5 addresses the event of a delayed fault clearing plus a non-redundant component of a protection system, such as a single DC supply, preventing the faulted element to operate as designed.
Installing a backup DC supply is expensive and requires additional space, but footnote 13c states it is not mandatory if the single DC supply is monitored for both low voltage and open circuit if reported to a control center.