• Definitions
• Advantages of semi-parallel systems
• Features and benefits of aluminium wire
• High intensity discharge lamps naming applied by leading producers in lighting

Definitions

ΔT (delta T)

It is the difference of temperature of the coil windings within an operating electromagnetic ballast compared to when it is in an off status.

ΔTabn (ΔT in abnormal situation)

It is the increase of winding temperature at 110% mains voltage when the starter is short circuited.

Tw (T windings)

It is the maximum temperature allowed for the windings in an electromagnetic ballast. When the temperature higher then Tw (130 or 140 degrees, depending on the ballast type), the isolation around the wire can be damaged.

Ta (ambient temperature)

It is the temperature specified for the product as maximum allowed surrounding temperature in the luminaire. The Ta (ambient temperature) of electromagnetic ballast is therefore approx. Tw-ΔT.

Thermo switch (TS)

It is for thermal protection against overheating. This prevents the ballast damage when the lamp reaches end of life.

PF (power factor)

It determines the amount of current that is consumed by a system. When the PF is low the current consumption is high. The PF can be improved by a PF capacitor or reactor (depend on PF character).

Reinforced ballasts (letter R in the naming)

These ballasts are designed to be used in class II luminaires.

Advantages of semi-parallel systems

• Ignitor is not self-heating
• Ballast generates high-energy ignition pulse that ignites lamps under all conditions
• Current does not flow through ignitor when lamp is operating therefore lifetime of digital semi-parallel ignitor can reach more than 10 years of operation
• High-energy ignition pulse, enabling remote gearing
• Silent system operation
• Semi-parallel ballasts can be used both with semi-parallel and series ignitors
• Semi-parallel system has lower energy consumption compared to series one

Features and benefits of aluminium wire

Raw material prices are growing, manufacturers of luminaires are looking for cheaper alternatives to improve their own competitiveness. Alternatives having equal or better performance. Because that MST decided to develop the new product platform based on aluminum wire. Years of experience in this field and positive users feedback unequivocally confirm the correctness of technological solutions adopted in the most critical elements of aluminium wire ballast design.

Main facts:

• aluminium wire has the same kind of insulation as copper wire (temperature index 200°C),
• experience with Fluo and HID ballasts with aluminium show that production process (winding etc.) has no negative influence on insulation quality,
• if during ballasts lifetime any insulation damages or cracks will appear, they will be quickly covered by oxide layer – due to this phenomenon overall insulation of aluminium wire is even better than copper wire,
• all ballasts with aluminium wire have Tw=140 (market standard is Tw=130),
• ballasts are tested (acc. IEC 61347) 30 days at 238°C (most of the copper wire ballasts are tested at 222°C)

High intensity discharge lamps naming applied by producers in lighting

	High-pressure sodium vapour lamps	Metal Halide Lamps	High-pressure mercury vapour lamps	Low-pressure sodium vapour lamps
MST	SON	MH, HPI	HPL	SOX
BAG	HS	HI/MH	HPI	-
ELT	Na	Hgl	Hg	-
Helvar	HS	HI	HM	-
OSRAM	Vialox NAV, Plantastar-T	Powerball HCI, Powerstar HQI	HQL	SOX
PHILIPS	SON	MHN, CDM, CDO, HPI	HPL	SOX
Tridonic	HS	HI	HM	-
Venture	HPS	MH	Mercury lamps	SOX
VosslohSchwabe	HS	HI	HM	-
Electrostart	HSI	MHI	MVI	-