According to an Osram Catalog, I seem to be getting this information about the operation of 4 pin PL-C and PL-S lamps on magnetic ballasts:
"3.2.3 Operation of
OSRAM DULUX®
S/E, D/E and T/E
with external
starter and CCG
OSRAM DULUX ® S, D and T lamps (with two-pin bases) have been designed specifi-
cally for operation with conventional control gear. Integrated in their bases is a special-
ly developed glow starter that has been adapted to the particular requirements of
these compact fluorescent lamps. OSRAM DULUX® S/E, D/E and T/E with four-pin
bases are intended for operation with electronic control gear, and hence without a star-
ter. Generally, it is possible to operate OSRAM DULUX® S/E, D/E and T/E lamps (13 W,
18 W and 26 W only) with conventional control gear and an external starter under nor-
mal operating conditions. However, there is no starter currently available on the market
that has been designed specifically for this purpose (see also 6.3).
In this mode, considerable limitations can therefore be expected, such as greatly
reduced lamp life with lamp glass blackening on the electrode side and longer
ignition times. For this reason, this mode of operation is not recommended or
supported by OSRAM."
In that case, should I expect the 2 pin PL-S and PL-C lamps to last longer than same wattage 4 pin PL-S and PL-C lamps on magnetic ballasts assuming external starters are used with such lamps?
In addition, I am also beginning to wonder why PL-S and PL-C lamps use specialized starters and not conventional starters.
Here is the link to the Osram catalog where I sourced this information from:
https://www.farnell.com/datasheets/301616.pdf