The ZTT/Plus employs a hot swappable inverter module in a rugged enclosure for easy field maintenance without interrupting network operations. Standard features include LCD panel, a front access DIN port for connection to various third party transponders, and a robust ferro capable of handling 200% short duration overloads. Following an outage, the ZTT/Plus delivers a constant 6A charging current under all load and line conditions. In the event of a short, the output is protected by a software controlled circuit breaker that cycles to protect downstream network amplifiers.