Thanks for your replies guys.
The application i use this set up is for DC indicator lamps in 11 kV substations, which run on 120 Volts dc from a battery bank.
Hero999 I use two resistors in series to dissipate the power over two instead of one resistor, which are easily available at electronics shops.
Most high efficiency leds are already very bright at 5 to 10 mA anyway. so there is no need to run the leds at 20 mA.
And of course you have to ensure that the polarity is correct at the other lamp terminal, which happened to be off. Most POCO's wouldn't be happy to trip feeder brakers to check a status indicator light. A small bridge rectifier could be inserted in the DC application, but i like to keep it as simple as possible.
On1aag The same concept can be used for AC as well. As already suggested use a 1N4007 diode in series with the circuit to reduce the power dissipation in the series R's.
Or the other concept can be used with the bridge rectifier too. The led will than run at 100 Hz.
Regards, Raymond