From software to relays, Utility Systems, Inc. ™ offers customers a variety of accessories to meet all digital fault locating and disturbance monitoring needs.

Model Ctr-1001

disturbance monitoring equipment

The USI CTR-1001 is a high accuracy solid-core current transformer for very low phase shifts. These auxiliary CTs are useful in many monitoring applications, such as Disturbance Monitoring Equipment (DME), Digital Fault Recording (DFR) inputs, and metering applications.


  • Turns Ratio: 1000:1
  • Rated Current: 100:0.1A
  • Phase Angle Error: <8 minutes from 1% to 100% or rated current
  • Secondary Open Protected: Voltage limited at 10V
  • Output: 25, 50, 125, 250, 375, or 500mV
  • Window Diameter (ID): 0.75”
  • Overall Diameter (OD): 2.25”
  • Width: 0.75”

Trip Indicating Relay (TIR)

disturbance monitoring

Constructed inside a rugged, high-dielectric case with terminal studs, the USI™ Trip Indicating Relay (TIR) is one of several USI™ premier accessories. This accessory provides outstanding quality connections with any connection. The USI™ TIR features millisecond actuation, high current capability, low resistance, and high switching capacity. Additionally, the TIR is not only low-cost, but also simple to install. The TIR has multiple functions, including alarm indication, annunciation, event recording, breaker, relay, and communication.

Also, a USI™ TIR is activated by sensing the presence of currents in a trip coil. Because of this the trip coil can handle extreme current overloads and features a high-speed contact closure time. Its special design is ideal for use with protective relays and circuits associated with DMEs (specifically the DFR application). To fit your company’s specific needs, USI™ TIRs are available in multiple arrangements, both pre-manufactured and customer-specific.(Click the View Screenshots link below).