Lamp manufacturers data will specify the required conditions for ignition. However, for commonly available lamps, the mains voltage and wattage are the only factors normally required to enable correct ignitor selection. (See Lamp Data Section). Most SON and Metal Halide lamps require an external ignitor. However, there are some lamps that include built in starters and some that operate only with special electronic power units.

Lampholders must be rated for use at the specified ignitor pulse voltage. Hot restrike ignitors, with pulse heights of greater than 5kV, can only be used with double ended TS or D2 lamps.

The use of timer type ignitors is recommended for additional safety. LIL S.I.P. ignitors are available with digital timer cut-out control, set to 2, 12 or 15 minutes

Ballasts are not subjected to very high voltages when used in superimposed ignitor circuits and, therefore, all normally available ballasts are suitable. The ignitor taps provided on some ballasts are not required, and should not be used in conjunction with superimposed pulse type ignitors.

Use of a ballast equipped with a thermal safety cut-out is recommended for additional safety.

The quoted maximum pulse voltage applies only if the load capacitance is within the limits stated. The value given is the highest peak voltage achieved by any one or more pulses in any sequence.

Load capacitance should be kept to a minimum by positioning the ignitor as close as possible to the lampholder. The maximum cable length depends on cable capacitance but the total capacitance must not exceed the quoted value, under any circumstances. Some typical values for the capacitance of PVC insulated cables (1.0 to 4.0mm2) are as follows :

1. Unsheathed single cores, loose packed in earthed conduit 70pF/m

2. Unsheathed single cores, tight packed in earthed conduit 120pF/m

3. Twin and Earth (Flat section) 115pF/m

4. Twin SWA/Multicore SWA/Unarmoured Multicore 300pF/m

During lamp running the lamp current, passing through the ignitor windings, will generate an internal heat rise in the ignitor. The value of the limiting temperature, as stated on the casing, should not be exceeded and the ignitor should be located in the coolest possible position, within the limits permitted by load capacitance considerations. Standard LIL Ignitors are intended for installation within a luminaire or suitable enclosure. For special applications contact our technical team.

High voltage cables must be suitably rated and insulated. All terminals must be tightened securely and firmly. Circuits must only be wired strictly in accordance with the wiring diagrams and the restrictions given herein.