ALSIDENT SYSTEM A/S
Finlandsvej 10 · DK-8450 Hammel · CVR nr. 57867612 · Tlf.: +45 86 96 50 00 · Fax: +45 86 96 50 10
Adjustment of internal springs:
By stationary positioning of the suction arm in the highest or lowest part of the working area, the
arm may rise. This happens when the spring in the socket joint is too tight for the position. This can
be corrected by mounting the arm at a lower point. If this is not feasible, the spring can be weak-
ened. In order to do so, the socket joint must be taken apart by screwing one of the finger screws
off the joint and pulling out the threaded stay. When the spring has been removed from the joint,
weaken it by pushing the “legs “ of the spring in
the winding direction.
However, if the arm is sinking from the wanted position, this could be due to greasing of the O-ring
with oils or fats causing loss of friction. In this case, the O-ring must be cleaned as described
above. Sometimes the spring can be weakened if the arm is positioned at the extremity of the work
area over a long period of time making the arm sink. In this case, the spring needs to be tightened
up by pulling the “legs” of the spring against
the winding direction.
On the figure below a spring is shown in three different positions: 1) a weakened spring, 2) a spring
in normal position and 3) a tightened spring. When the spring needs to be bent do it in a distance
app. ⅓ ·h from the winding. The angle, v, depends on the need for tightening/weakening, and it is
advisable to test one’s ground in small stages (i.e. 5° at a time).
The shown spring is made for use in
HM/HMS arms with three joints.
For all springs the following apply:
When weakening
a spring, bend the
legs in
the winding direction.
When tightening
a spring, bend the
legs against
the winding direction.
Gas springs:
Some of the arms 75-9065 and 75-9090 are equipped with external gas springs. The gas springs
are maintenance free, but should be cleaned regularly. The gas springs must not be retracted or
extended beyond there stroke in both directions nor be exposed to impacts. The gas springs must
not be used as handles, and non-axial (sideway) forces must be avoided. The gas springs are
considered wearing parts.
The antistatic suction arm
:
The arm is constructed of tubes and joints of conductive Polypropylene (PP), giving the arm con-
ductive properties.
When delivered the socket pipe of the arm is provided with a wire prepared for EX-areas. In EX-
areas, it is important to balance the potential of the suction arm with the rest of the ventilation sys-
tem and the earth wire must therefore be connected with the ventilating duct.
If the arm is to be mounted in an ESD-area, the pre-attached wire must be replaced by the en-
closed ESD-wire with a resistance of 1 MΩ. The ESD arm then must be earthed together with the
other equipment in order to give the suction arm the same potential as the rest of the area. This
prevents a strong discharge, which could damage the electronic equipment. We recommend that
an electrician with experience in ESD-areas earths the wire.
Since the resistance of 1 MΩ is very important in ESD-areas, please be careful not to break the
resistance.