T5 Watt-Miser

T5 Watt-Miser linear fluorescent lamps

T5 Watt-Miser lamps are triphosphor fluorescent lamps with 16mm outer diameter for indoor applications. These new lamps offer significant energy savings versus other T5 linear fluorescent lamps.

T5 Watt-Miser lamps consume 5% less energy compared with today’s T5 lamps. Without compromising lumen output, and have a 25,000 hours life.
T5 lamps are optimized to higher ambient temperature than T8 lamps, offering up to 111lm/W luminous efficacy. The peak lumen output can be reached at approximately 35°C. The elevated optimum temperature results in additional energy saving versus T8 lamps in typical indoor lighting applications.
Standard T5 lamps can be easily replaced with the new T5 Watt-Miser lamps in the existing lighting applications, since new electronic control gears are not required. These new lamps from GE enable even less than 6 months payback time.
GE is committed to fight against climate change. The T5 Watt-Miser lamps will contribute to the global effort to reduce CO₂ emission. One lamp can save 1.2-5.0 kg carbon dioxide per year depending on the type. So in addition to the lower energy bill, millions of tons of CO₂ could potentially be saved with this new lamp technology in Europe.

Product Range
T5 Watt-Miser lamps are available in 9 wattages and 4 standard colour temperatures. Each already known T5 lamp has it Watt-Miser equivalent couple. For easy identification, the stamping colour is green, and the new product descriptions refer to the existing standard nominal wattages. E.g. a luminaire having already-known F14W Starcoat T5 lamp inside, can be relamped with the new F14 Watt-Miser.
The entire range consists of the following models:
• 2-ft F14, F24
• 3-ft F21, F39
• 4-ft F28, F54
• 5-ft F35, F49, F80

The available colour temperature are:
• 3000K warm white
• 3500K white
• 4000K cool white
• 6500K daylight

Application areas
T5 Watt-Miser lamps are mostly recommended for general indoor applications, such as:
• Retail
• Offices
• Schools
• Commercial
• Industrial

The T5 Watt-Miser linear fluorescent lamps comply with IEC 60061, IEC 60081 and IEC 61195

Basic Data

Spectral power distribution

Typical values

Service life curve is defined as the product of the survival rate and the lumen maintenance. The rated value is at 80%.

Influence of ambient temperature on light output

Lamps performance parameters, such as luminous output, lamp voltage and power depend on the mercury vapour pressure in the discharge tube. The mercury vapour pressure is affected bu the thermal conditions determined by factors such as burning position, air flow, radiating heat sources, etc. T5 lamps produce the maximum lumen output at approximately 35°C ambient temperature. It is approximately equivalent to 45°C cap temperature which can be more easily measured in a luminaire. For maximum performance, the use of electronic control gears with cathode cut-off technology is recommended.

Typical Values

Information for control gear manufacturers and OEMs

Electrical and photometric characteristics

Rated electrical characteristics are valid at 35°C ambient temperature after 100 hours burning. Lumen and efficacy values are valid for colour temperatures 3000K, 3500K and 4000K.

Starting requirements
Starting requirements comply with IEC 60081. Suitable preheating of the cathodes prior to ignition is essential for long lamp life. The preheating requirement can be given by the following formula:
E = Q + Pt for 0.4...3.0s starting times.
E is the energy dissipated on a suitably chosen substitution resistor.
Rsub.Q represents the necessary thermal energy to raise the cathode temperature, while P describes the heat loss of the cathode. During longer preheating, the cathode loses more heat to its surrounding. Parameters for the current controlled and the voltage controlled modes can be derived from the formula. Ignition voltage (OCVmin) is defined for starting at -15°C ambient temperature.

Dimming is done by reducing the discharge current. As a result, the electron emissivity of the cathodes will decrease. Since it may have a negative impact on lamp life, additional cathode heating should be applied by the electronic control gear.
ILH²+ILL²=X-YID, where ILH and ILL are the currents in the lead-in wires to the cathode; ID is the discharge current.

Recommendation for measuring T5 lamps
In order to minimise stabilisation time, handle T5 lamps in vertical position with the “cold spot” at the lowest point as much as possible. During testing, the luminous flux of the lamp should be stabilised. Stable light output is reached when all the liquid mercury is in the cold chamber. Before measuring, T5 lamps should be seasoned for approximately 100 hours in a vertical position with the cold chamber (stamp side) at the lowest point. If the lamps are switched off for more than 12 hours, they are to be burnt for at least 4 additional hours with the cold chamber down. Placing lamps into the test system the cold chamber should be kept at the lowest point as much as possible. After placing the lamp within the test system and before measuring the stable luminous flux, lamps should be continuously burnt for one hour. Stability should be checked by monitoring the luminous flux. The measured luminous flux may be considered stable if the relative change in light output is less than 0.5% over a 5 minute period.