VS_2017

Technical Details – Components for Discharge Lamps
Lampholders for High-pressure
Discharge Lamps
Metal halide and high-pressure sodium lamps feature extremely different bases, which include RX7s,
Fc2, G8.5, GX8.5, GU8.5, GX10, G12, GX12, PG12, PGJ5, GU6.5, E27 and E40, depending on
whether the lamp is single- or double-ended. All lampholders are subject to the same typical conditions
found with discharge lamps: high ignition voltages and temperatures. The high start-up currents deserve
particular attention in lampholder design. This is also reflected by the insulation materials, which are
usually solid ceramics or heat-resistant plastic (e.g. PPS – polyphenylene sulphide). Depending on the
lamp's requirements (voltage, current, temperature, etc.), silver, nickel and copper alloys with thick nickel
coatings are used as conductors. The luminaire regulation EN 60598-1 (VDE 0711 part 1), defines the
safety requirements with regard to ignition voltages in connection with creepage and air clearance
distances. Special care must be taken to ensure that lampholders are approved for discharge lamps
when using high-pressure lamps with E27 and E40 Edison bases. Lampholders that are suitable for this
purpose are marked with a maximum value of "5 kV" and comply with the increased creepage and air
clearance distances specified by the lampholder requirements in EN 60238 (VDE 0616 part 1). The
lampholder regulations governing special lampholders, EN 60838-1 (VDE 0616 part 5), apply
analogously to all other base systems. The high ignition voltage pulses also place special demands on
the conductors. In practice, silicone-insulated conductors with an outer diameter of 3.6 mm have proved
to be suitable for discharge lamps. Silicone-insulated conductors with a glass-silk lining with a diameter
of 7 mm should be used for lamps with an instant hot restart (20 kV) function.
VS lampholders for the UL
market and UL approved
leads are available for all
common lamp types.
Further information can be
found at www.unvlt.com.
When connecting lampholders to push-in terminals of ballasts, the diameter of the conductor and the
length of the stripped cables must be taken into account to ensure correct operation of the installed
components. To this end, Vossloh-Schwabe can make additional versions available with compacted
cable ends as further options.
When using compacted cable ends, the reduction of the cable diameter at the end of the cable must
be taken into account, which means that the respective ballast push-in terminal has to be capable of
taking the next-smaller cable diameter (see table with examples).
When using screw terminals to connect a ballast, it is recommended to use a ferrules on the bare end
of core.
Cable cross-section Push-in terminal range on the ballast when using compacted cable ends
mm²
mm²
0.75 0.5
1 0.75
Bases for the most commonly used HI and HS lamps
96