Q: Do the R-3W series voltage indicators have internal short circuit protection?

A: Yes, the voltage indicator is protected by high impedance circuitry and recognized components that limit the power to 1.2watts @ 750 Volts AC. The following chart gives the phase to ground short circuit currents.

Voltage Indicator included Fault Current (PHASE-TO-GROUND SHORT)

3- Phase Line-To-Line (VAC) 30 120 240 480 750

0 OHM Phase-To-Ground Current (μA) 28 108 219 455 730

The R-3W is a unique device because it is wired between all three phases and is effectively ‘short circuiting’ all the phases. Under normal circumstances this device allows only 100-200 micro Amps to pass between phase and ground. If a short circuit occurs in a system where an R-3W is installed, the high currents that pass through the system would not find a path through the R-3W and would not cause any damage to the device. Therefore the SCCR rating is not applicable for the R-3W.