Pad-Mounted Transformers With Low Primary Voltage—Apply SEL-SRs to pad-mounted transformers when there is insufficient primary voltage to power and reset voltage-powered fault indicators.
Pad-Mounted Transformers Without Capacitive Test Points—Install the SEL-SR in pad-mounted transformer applications without capacitive test points and where there is insufficient primary load current to power a current-powered fault indicator.
Daily Changes in Load Current—Monitor residential single-phase transformers with the SEL-SR. The SEL-SR’s ability to power from secondary voltage ensures it will detect faults during lightly loaded circuit conditions. Circuits feeding residential areas with daily changing load currents may see a significant drop in load current as home owners leave for work or go to sleep late at night. In some cases, circuit loading can drop to levels below the minimum current requirement of most faulted circuit indicators.
Seasonal Changes in Load Current—Install the SEL-SR on circuits feeding areas with seasonal changes in load, such as school campuses and resorts. These circuits may see little to almost no load while the facility is not being occupied. Since faults can still occur on these circuits, the SEL-SR will help identify the fault location, allowing crews to repair the circuit and ensure it is operational in time for the next season.
|Power Source||Secondary voltage|
|Secondary Voltage||110 to 460 VacL-N|
|Nominal Trip Ratings||50 to 1,200 A|
|Trip Tolerance||±10 percent|
|Reset Time*||Approximately 30 seconds at 120 Vac|
|Maximum Fault||Current 25 kA for 10 cycles|
|Trip Response Time||1 ms|
|Outer Diameter Clamping Range||0.75" to 1.6" (Specify the clamping diameter or range when ordering.)|
|Housing Material||UV-stabilized polycarbonate resin|
|Clamp Material||Stainless steel|
* Product may vary depending on configuration