Nederman VAC 12, Instruction Manual

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VAC 12/20 EN
20
The MAX relay is activated if the current is higher than a set maximum
value (closing the valve). If the current is within the ‘dead band’ between the
minimum and maximum settings, no relay is activated and the valve is static.
5 Main components
5.1 Overview
Figure 1 shows the main components of the VAC 12/20 unit. These are as
follows:
1. Acoustic enclosure.
2. Motor.
3. VAC 12: High pressure fan.
VAC 20: 2-stage high pressure fan.
4. Start-up valve. VAC 12 has model TVS 200. VAC 20 has model SUV 200
which also serves as a back flush valve. 24 V DC is supplied as standard
but a solenoid for 24 V AC is also enclosed.
5. VAC 20: Temperature control valve. 24 V AC/DC is supplied as standard.
The valve may be replaced by the anti surge valve, Item 6.
6. VAC 20: Anti surge valve. Optional replacement for the temperature
control valve, Item 5.
7. VAC 20-1500/2500/3000: Flow restrictor FR 160, see also Figure 4.
8. VAC 20: Thermal switch for fan housing. Used with temperature control
valve only.
9. VAC 20: Manual reset thermal switch for the fan bearings. See also
Figure 13 for details.
10. Belt transmission.
The optional inlet silencer is shown in Figure 2.
1. Optional: Inlet silencer for extra low noise levels indoors.
5.2 Connections
Figure 5 is a schematic diagram of the normal connections to a VAC unit. For
electrical connections, see the start and control unit’s manual and also Figure
6–8. Connections may vary depending on the options chosen. Connecting
material such as cables are not included with the unit. See the dust collector
manual for information about dust collector connections.
Most failures are result from faults in the electrical equipment or connections.
The motor overload relay must be of the ‘heavy start type’ as some units are
heavy to start. Otherwise the motor overload may trip because of the high
current and the long time spent in the Y-mode.
NOTE!
Electrical installation must be made by a qualified electrician.
NOTE!
National and local electric regulations must be followed.
Start and control units from Nederman have terminals for easy connection of
all control cables. If other equipment is used, this equipment must be similarly
equipped and connected for the guarantee of the VAC 12/20 unit to be valid.