There is no simple figure. - the old 1.8 was based on the ratio of tube voltage (about 100) to supply voltage (about 240) and some assumptions about how much current flows through the series choke while  the tube is shorted out by the starter to get the heaters warmed up and the mercury from drops into vapour.

LEDs just do not work that way, and the only sure fire way to find out is to check with the makers of the fittings. Do you have a part no, or link to maker's data ?


Once up and running the current should be very close to the theoretical  2/3  of an amp for 150watts, as proper fittings over 25watts should  have proper power factor correction built in if they are allowed to be sold in the EU.

Inrush may be very high (tens of amps), but it will be all over in less than one half cycle, so a C-type MCB will be more than adequate, and cable can be thin... If you had a lot of them, then I'd also say keep an eye on the earth leakage, and if need be  break out the lighting wiring onto their own RCBO, for a couple, less of an issue.


Edit An example driver from  far eastern maker  Meanwell     common inside fittings from companies without an electronics reputation, says 75A inrush for a 150W driver.

A few ohms in series would reduce that a lot, but add a few watts to the standing losses so they tend not to do that.


You may need a 10A C type if both come on at once. The exact shape of the under hang of the timing curve for times shorter than 100ms is not tested or guaranteed by MCB makers but is typically a bit like this example

There is no simple figure. - the old 1.8 was based on the ratio of tube voltage (about 100) to supply voltage (about 240) and some assumptions about how much current flows through the series choke while  the tube is shorted out by the starter to get the heaters warmed up and the mercury from drops into vapour.

LEDs just do not work that way, and the only sure fire way to find out is to check with the makers of the fittings. Do you have a part no, or link to maker's data ?


Once up and running the current should be very close to the theoretical  2/3  of an amp for 150watts, as proper fittings over 25watts should  have proper power factor correction built in if they are allowed to be sold in the EU.

Inrush may be very high (tens of amps), but it will be all over in less than one half cycle, so a C-type MCB will be more than adequate, and cable can be thin... If you had a lot of them, then I'd also say keep an eye on the earth leakage, and if need be  break out the lighting wiring onto their own RCBO, for a couple, less of an issue.


Edit An example driver from  far eastern maker  Meanwell     common inside fittings from companies without an electronics reputation, says 75A inrush for a 150W driver.

A few ohms in series would reduce that a lot, but add a few watts to the standing losses so they tend not to do that.


You may need a 10A C type if both come on at once. The exact shape of the under hang of the timing curve for times shorter than 100ms is not tested or guaranteed by MCB makers but is typically a bit like this example