OSRAM POWERTRONIC PT-FIT I ECG for HID lamps, with cable clamp - Manual (Page 18)

THE PRODUCT IN OPERATION
18
The observations of temperature must be made separately
for the two system components (ECG and lamp). For the
lamp there are legal provisions that restrict the tempera-
ture range and the boundary temperatures to be respected
for safety reasons.
For the ECG fi xed restrictions must be defi ned for reasons
of operational safety. Starting from the separate obser-
vation methods, there are outside infl uences on luminaire
installation which play a substantial role in infl uencing the
ECG, lamp and luminaire, as well as the choice of installa-
tion position.
Complying with the required restrictions and thus
en suring operational safety is the responsibility of the
manufacturer of the luminaire.
2.3.6. ECG temperatures and their effect on service life
In evaluating the properties of an ECG, considerations
relating to their thermal behavior in relation to maximum
permissible temperatures are decisive. In this context one
should always distinguish between the ambient tempera-
ture of the luminaire, the ambient temperature of the ECG
and the temperature of the ECG casing.
The following diagram illustrates these temperatures:
2.3.5. Power factor, compensation
For all devices that consume electricity, the power factor λ
is the ratio of effective power (P
Effect
= U x I
Effect
) to apparent
power (P
Appar
= U x I). This value is affected both by the phase
displacement cos φ between the current and the voltage
and by the current distortion ε (deviation from the sinusoidal
shape).
λ = P
Effect
/ P
Appar
= ε cos φ
In contrast to conventional control gear (CCG: inductive,
50 Hz), with electronic control gear there is practically no
phase displacement present. There is therefore no need
for any compensation. However, during the operation of
electronic control gear small distortions in the sinusoidal
mains current may appear. In general, these distortions
are also described by harmonics or overtones.
The harmonic content of the line current is strictly con-
trolled by national and international standards
(IEC 61000-3-2). In order to conform to these standards,
OSRAM electronic control gear units have fully electronic
harmonics fi lters built in, which ensure that ε > 0.95 and
thus that power factor λ ≥ 0.95. From this point of view
ECGs are signifi cantly better than CCGs.
Exception:
For system wattages of less then 25 W, there are simplifi ed
evaluation criteria for harmonic content, so that in such
cases a power factor of λ ~ 0.6, for example, may
be permissible.
All POWERTRONIC ® devices have been tested in relation
to mains current harmonics content in accordance with
EN 61000-3-2 by VDE and carry the VDE EMC symbol:
Figure 21: Schematic diagram of a luminaire's structure
Ambient temperature of luminaire
Temperature of ECG casing (t
c
)
Ambient temperature of ECG (t
a
)