Maybe, Jamie, maybe. 
I did a few sums. The cold resistance of the light bulb is 240 ohms.
If we assume:
(1) that its hot resistance is twice that, 480 ohms, then the voltage across the bulb is 44 volts. This gives a current in the circuit of 92 mA. Hence, the voltage-drop across the line cord is 76 volts; its resistance is 826 ohms. The power dissipation in that line cord will be in the region of 7 watts.
If we assume:
(2) that its hot resistance is 150 % of that, 360 ohms, then the voltage across the bulb is 38 volts. This gives a current in the circuit of 105 mA. Hence, the voltage-drop across the line cord is 82 volts; its resistance is 781 ohms. The power dissipation in that line cord will be in the region of 9 watts.
So, taking a mean figure of 8 watts dissipated by the line cord, I have to ask: "Is this a reasonable amount of heat that can be tolerated by such a voltage-dropping line cord?" (Especially as this bulb is situate in a fire station? :s )
I strongly suspect that in my first extracted quote, when it was stated "only turned on for about four watts", the person actually meant "only turned on for four hours (per day)". Or that that person was simply mis-quoted. Moreover, why would the installer of this bulb choose to fit a voltage-dropping line cord in the first place, especially since the light output from the bulb will then only be in the region of 4 watts? Hardly an illuminating source!
Al.
I did a few sums. The cold resistance of the light bulb is 240 ohms.
If we assume:
(1) that its hot resistance is twice that, 480 ohms, then the voltage across the bulb is 44 volts. This gives a current in the circuit of 92 mA. Hence, the voltage-drop across the line cord is 76 volts; its resistance is 826 ohms. The power dissipation in that line cord will be in the region of 7 watts.
If we assume:
(2) that its hot resistance is 150 % of that, 360 ohms, then the voltage across the bulb is 38 volts. This gives a current in the circuit of 105 mA. Hence, the voltage-drop across the line cord is 82 volts; its resistance is 781 ohms. The power dissipation in that line cord will be in the region of 9 watts.
So, taking a mean figure of 8 watts dissipated by the line cord, I have to ask: "Is this a reasonable amount of heat that can be tolerated by such a voltage-dropping line cord?" (Especially as this bulb is situate in a fire station? :s )
I strongly suspect that in my first extracted quote, when it was stated "only turned on for about four watts", the person actually meant "only turned on for four hours (per day)". Or that that person was simply mis-quoted. Moreover, why would the installer of this bulb choose to fit a voltage-dropping line cord in the first place, especially since the light output from the bulb will then only be in the region of 4 watts? Hardly an illuminating source!
Al.
