MAFS0 pages

MAFS

Multiple Chopping Gap
The multiple chopping gap is a originally
patented Haefely development and is used to
chop lightning impulses (on the front and on
the tail) as well as switching impulses up to
the highest voltages.

The sphere distance is automatically adjusted by the
controls GC 223, GC 257.
In the automatic mode, their distance is set
automatically in function of the charging voltage. The
gap distance is displayed on these controls. The
chopping is initiated by the first stage, having a
triggering plug.

The multiple chopping gap serves
simultaneously as a load capacitor for the
impulse generator and allows excellent
reproducibility of the chopping time and does
not distort the wave shape until the chopping
point.

A manual control box GSC 219 is available to adjust
the gap distance standalone or with non-Haefely
control systems.

With a additional secondary unit the MAFS is
also usable for some applications as a voltage
divider.
Rod gaps and sphere gaps (above 1000 kV)
draw a substantial pre-discharge current prior
to the voltage break-down, causing a voltage
drop. This affects the comparison tests when
testing power transformers.

Design
For indoor operation and mobile design.
The HV units are made of stacked capacitors with
inserted damping resistances. This active part is built
in reinforced fibre-glass cylinders.
Our active part technology is derived from our decadelong experience. The copper spheres have tungsten
sintered inserts to reduce the burn-off. Their distance
is set by a precise drive. The upper semi-sphere is
attached to a movable frame which makes it possible
to adjust simultaneously all partial spark gaps.
The multiple chopping gaps are equipped with toroid
electrodes. The electrodes are made of brushed
aluminium. The electrode type is determined by the
rated voltage. Fibre-glass struts are required when
more than 2400 kV units are used.
The H base frame of welded steel profiles is equipped
with four swivel castors.

Multiple chopping gap MAFS in front of an SGDA

Multiple chopping gap MAFS 2400

Subject to change without notice.

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