Ungrounded, unearthed, or "floating" power systems are those without intentional conductive connections to earth's or chassis ground. These systems have the advantage of not being disabled by a single short, making it crucial to continuously monitor their isolation state for safety. International standards require isolation monitors to perform this function. This paper reviews potential hazards in IT systems and common methods for detecting isolation faults, identifying safety issues and highlighting unique features of Sendyne's SIM100 Insulation Monitoring Device. The whitepaper, originally published in 2019, provides capacitance estimates and performance data for the Sendyne SIM100 Insulation Monitoring Device.