General - Philips E 401 Serie Gebrauchsanweisung

3
VARIABLE TRANSFORMERS
of series E 401 with casing 1-9 A
General
A. Electrical data
B. Safety
0
On the type plate of the Variable Transformer are indicated:
primary voltage, frequency, output voltage range and rated second-
ary current.
The transformer has been provided with a centre tapping so as to
enable voltage corrections to be made by means of a buck-boost
transformer.
Under certain conditions of use an overload up to 40 % is permis-
sible. For a short-term overload even 1000 %. Full details are
shown in the appropriate catalogue sheets.
If the transformer is connected to the mains via a fuse, it should be
taken into account - that transformers with core material of high
permeability are liable to surge currents which can be as high as
20-times the maximum load current.
Owing to the short duration of these phenomena (approx. 5 cycles)
the transformer will not be damaged. However, electro-magnetic
safety devices and fuses may be put into operation. A practical
alternative is adelayed-action fuse or a thermal trip.
For protecting the transformer itself,
a
fuse must be incorporated
in the secondary lead.