
i.1
[en] 02/2014
Installation and operating manual - NK 31
1 Foreword............................................ 1.1
1.1 General ............................................... 1.1
1.2 Scope.................................................. 1.1
1.3 Change service................................... 1.1
1.4 Abbreviations ...................................... 1.1
1.5 Manufacturer’s information ................. 1.1
1.5.1 General information ............................ 1.1
1.5.2 Purpose............................................... 1.2
1.5.3 Standard delivery scope ..................... 1.2
1.6 Warranty information,
liability disclaimer................................ 1.2
1.7 Nameplate........................................... 1.2
2 Safety precautions............................ 2.1
2.1 Marking of safety precautions............. 2.1
2.2 Safety regulations ............................... 2.1
2.3 General safety precautions................. 2.1
2.3.1 Special symbols.................................. 2.2
2.3.2 Instructions to use safety equipment .. 2.2
3 Technical Description....................... 3.1
3.1 General overview of NK 31
Screw Compressor Compact Module
(standard model with electric control
unit)..................................................... 3.1
3.2 Flow diagram of NK 31
(electric control unit)............................ 3.2
3.3 Operating description for NK 31
Screw Compressor Compact Module
(electric) .............................................. 3.2
3.3.1 Standstill ............................................. 3.2
3.3.2 Relieved stating .................................. 3.3
3.3.3 Feed phase......................................... 3.3
3.3.4 Switching off........................................ 3.3
3.4 General overview of NK 31
Screw Compressor Compact Module
(standard model with pneumatic
control unit) ......................................... 3.4
3.5 Flow diagram of NK 31
(pneumatic control unit) ...................... 3.5
3.6 Operating description for NK 31
Screw Compressor Compact Module
(pneumatic)......................................... 3.5
3.6.1 Standstill ............................................. 3.5
3.6.2 Starting................................................ 3.6
3.6.3 Switching off........................................ 3.6
3.7 Flow diagram of NK 31
(START-STOP controller).................... 3.7
3.8 Operating description for NK 31
Screw Compressor Compact Module
(START-STOP controller).................... 3.7
3.8.1 Standstill ............................................. 3.7
3.8.2 Load condition..................................... 3.8
3.8.3 Switching off........................................ 3.8
3.9 Intake valve......................................... 3.9
3.9.1 Installation position ............................. 3.9
3.10 Intake air lter ................................... 3.10
3.10.1 Micro air lter element....................... 3.10
3.10.2 Intake lter monitoring....................... 3.10
3.11 Fine separator....................................3.11
3.11.1 Oil intake non-return valve.................3.11
3.11.2 Fine separator cartridge.................... 3.12
3.11.3 Minimum pressure valve................... 3.13
3.12 Air-oil circulation outside
compressor module .......................... 3.14
3.12.1 Oil lter.............................................. 3.15
3.12.2 Oil thermostat.................................... 3.15
3.13 Oil cooler/air after-cooler (option) ..... 3.16
3.14 Safety valve (SIV) (option)................ 3.16
4 Transport ........................................... 4.1
4.1 Delivery and packing........................... 4.1
4.2 Transport damage............................... 4.1
4.3 Transporting unpacked system........... 4.2
4.4 Transport options ................................ 4.2
5 Installation/Assembly....................... 5.1
5.1 Connection thread/assembly .............. 5.1
5.1.1 Fastening screws................................ 5.1
5.1.2 Pipe connections................................. 5.1
5.2 Safety precautions for installation
and assembly...................................... 5.1
5.3 Installation........................................... 5.2
5.3.1 Fastening on base frame with
screw tting......................................... 5.2
5.3.2 Drive.................................................... 5.2
5.4 Belt drive............................................. 5.3
5.5 Direct drive.......................................... 5.3
5.6 Air outlet.............................................. 5.4
5.7 Oil cooling ........................................... 5.4
5.8 Service................................................ 5.4
6 Commissioning................................. 6.1
6.1 Preparation for commissioning ........... 6.1
6.2 Checking direction of rotation ............. 6.1
6.3 Test run ............................................... 6.1
6.4 Recommissioning screw compressor
system................................................. 6.2
Contents