Anti-Surge Control; Bearing Temperature Switches; Optional: Compressed Air Switch; Before Installation - Nederman VAC 20 Manual De Instrucciones

cylinder, a piston moves freely. The damper only af-
fects rapid movements that could cause self-oscil-
lating. Rapid movements are hindered by the oil that
must pass by the piston in a small gap between the
piston and the cylinder wall.
4.5 Anti-surge control
Figure 13 shows the main components of the anti-
surge control. These are as follows:
1 Silencer.
2 Valve TVS 76.
3 Control motor. 24 V AC.
4 Cable.
5 Optional: Current transformer. 100/1 A.
6 Optional: Universal relay. 24 V AC.
7 Optional: Current sensing relay, 2 units MAX and
MIN. 24 V AC.
VAC versions' which anti-surge control is controlled
by, the start and control unit does not have compon-
ents 5, 6 or 7.
4.6 Bearing temperature switches
The circuit trips at temperatures over 110°C (230°F)
and the unit is stopped. Thermal tripping results in an
error indication in the starting equipment.
and Figure 7 show a circuit diagram for the overheat-
ing cut-out for the bearings on VAC 20. The circuit in
the start and control unit must require a manual reset.
The voltage must not exceed 24 V.
4.7 Optional: Compressed air switch
An optional compressed air switch can be mounted in
the vacuum unit to prevent it from starting with no
compressed air supply. No air supply must result in an
error indication in the start and control unit.
For electrical connections, see
and also the Start and Control Unit manual. The com-
pressed air switch is wired in series with the thermal
fuse. Use a jumper to connect the terminals if no com-
pressed air switch is used.
5 Before installation
5.1 Delivery check
Check the VAC 20 unit for any transport damages. In
case of damage or parts missing, notify the carrier and
your local Nederman representative immediately. It is
recommended to transport the VAC 20 unit to the in-
stallation site while still in the factory packing.
5.2 Installation requirements
5.2.1 Location
Prepare the location where VAC 20 is to be placed be-
fore installation. An open working space around the
unit is necessary for maintenance. A gap of at least
VAC 20
Figure 6
Figure 6 or Figure 7
0.7 meters in front of the unit is required to allow for
the opening of the unit.
5.2.2 Foundation
The unit must be anchored to a hard, level and firm
foundation, such as a concrete foundation.
Consider the total weight of the unit with accessories,
see Section 3.1 Technical
foundation or supporting structure.
6 Installation
6.1 Installing VAC 20
WARNING! Risk of cutting injury
Ensure the dust collector is attached to the
unit's inlet and the silencer attached to the
outlet. Suction at the inlet is very powerful and
any contact with the fan wheel could result in
severe injury.
WARNING! Risk of personal injury
Use ear protection and safety goggles during
the installation of the unit!
WARNING! Risk of personal injury
Lock the main compressed air valve in the
closed position during maintenance.
The unit can be placed indoors or outdoors.
Consider the following when installing VAC 20:
• The foundation is to be level and hard, see
tion 5.2.2 Foundation.
• Install VAC 20 away from heat sources or hot sur-
faces.
• Ensure that handling is convenient.
• Ensure that service and maintenance are conveni-
ent.
• Beware of hot air from the outlet.
• Ambient temperature must be within operating
temperature defined in
• Make sure the exhaust duct is protected from the
rain.
• Make sure the exhaust duct has a grid so no objects
can get into the duct.
6.1.1 Indoor installation
Also, consider the following when installing VAC 20
indoors:
• There are to be at least two ventilation openings
for ventilation, at least 250×250 mm (10"×10") in
size. One is to be placed up high and the other on the
down-low.
• Never seal a small room with a VAC 20unit installed
completely. At some stages, the unit will admit air
directly into the roots pump. This can cause a dan-
gerous underpressure in the room if the airflow is
obstructed.
data, when calculating the
Sec-
Section 3.1 Technical data.
EN
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