AKZ
Plant designation system AKZ
The plant designation system AKZ is a predecessor system for identifying plants, systems, sub-systems, and equipment items for plant operating companies. The implementation of AKZ is formalized by commonly known regulations. The AKZ system is now no longer developed and maintained as a designation system. The application is based on technology from 1975 and for this reason it is no longer recommended.
Identification of plants using this plant designation system comprised of a 9 to 10-character combination of letters and numbers. The letters were usually used for the classification of the systems and units, whereas the numbers were used for numbering.
The plant designation system AKZ distinguishes among 4 designation blocks:
| Nummer der Gliederungsstufen | Ordnungsstufe 0 | Ordnungsstufe 1 | Ordnungsstufe 2 | Ordnungsstufe 3 | Ordnungsstufe 4 |
| Aufbau des Kennzeichens | Gesamtanlage | Systemklassifizierung | Systemzählung | Aggregatklassifizierung | Aggregatzählung |
|---|---|---|---|---|---|
| Aufbau der Datenstellen | N | AA | NN | A | NNN |
The plant designation system according to AKZ followed a fixed structure that was based on grouping levels for designation, whereby the level of detail of the designation increases from left to right. The structure of the grouping levels was alphanumeric. In the example we use A for letters and N for numbers for the sake of simplicity.
Designation block 0 of the AKZ system – Entire plant
The first designation block refers to the overall plant and merely numbers it. It only consists of one digit. This is used to identify the power plant unit.
Designation block 1 of the AKZ system – Function designation
The second of the four designation blocks denotes functions, systems, or subsystems of a power plant. This designation block consists of 2 letters. These were assigned according to a predetermined function key for the systems in power plants. The first letter (from the left) refers to the main systems (also known as the main groups); the following letters were used for further subdivision into subgroups. The AKZ function key for plant designation is defined but is no longer maintained centrally.
Example of a function key for AKZ
Electrical engineering
| AKZ | Designation |
| A | High-voltage systems for power distribution, main transformer systems |
| AB | 110kV 162/3 Hz traction systems |
| AE | 110kV systems 50 Hz |
| AH | 50 kV systems |
| AJ | 20/25kV systems |
| AK | 10 kV systems |
| AP | Generator leads |
| AS | Reactors |
| AT | Unit transformers |
| AU | Coupling transformers |
| AV | Unit generator transformers |
| B | High-voltage auxiliary systems and auxiliary transformers |
| BA | HV unit auxiliary transformer, half busbar 1 |
| BB | HV unit auxiliary transformer, half busbar 2 |
| BC | Medium-voltage main system, starting system |
| BD | Main distribution boards |
| BE | Main distribution boards |
| BF | Main distribution boards |
| BG | Main distribution boards |
| BH | Unit auxiliary generator and appurtenances |
| BJ | Main unit auxiliary system |
| BK | Unit auxiliary batteries |
Mechanical engineering
| AKZ | Designation |
| P | Fuel handling |
| PA | Coal unloading and storage |
| PB | Coal treatment and transportation |
| PD | Oil unloading and storage |
| PE | Oil transportation and distribution |
| PG | Gas reception |
| PP | Waste unloading and storage |
| PQ | Waste treatment |
| PW | Means of transportation for fuel |
| PY | Brown coal dust transportation |
| Q | Gas turbine systems |
| QA | Turbine and generator casing and rotor |
| QB | Turbine bearing |
| QC | Oil system |
| QD | Combustion chamber |
| QG | Exhaust gas, fresh air supply |
| QJ | Starting equipment |
| QK | Ignition unit |
| QM | Oil firing |
| QN | Gas firing |
| QS | Cooling water system |
| QX | Starting system |
| R | Water-steam circuits |
| RA | Main steam pipe, HP bypass |
| RB | Hot reheat pipe, LP bypass |
| RC | Cold reheat pipe |
| RD | 2. reheat |
| RE | 3. reheat |
| RF | Extraction point for HP economizer |
| RG | Extraction point for district heating |
| RH | Extraction point for LP economizer |
| RJ | Heat transfer system |
Designation block 2 of the AKZ system – Function numbering
Designation block 2 comprised of two characters. These were referred to as FN-numbering and were used for numbering.
Designation block 3 of the AKZ system – Equipment unit designation
The third designation block was used to label an equipment unit in the subgroup. It consisted of only one letter. The equipment units were classified according to a defined equipment unit key for power plants.
Equipment unit key for grouping level 3
| AKZ | Designation |
| A | Analyt. meas. (chem. analysis, pH value, conc. etc.) |
| B | Vessel, apparatus, heat exchanger |
| C | Closed-loop control |
| D | Driven machine, driving machine (pumps, blowers, …) |
| E | Electr. meas. (current, voltage, frequency, etc. ) |
| F | Flow rate measurement, quantity measurement |
| G | Weight |
| H | Electrical and I&C equipment (horns, revolving lights, etc.) |
| J | Photoelectric cells |
| K | Characteristic value calculation, protection equipment |
| L | Level measurement |
| M | Special measurement (e.g. moisture, leakage, etc.) |
| N | Room, location, slot |
| P | Pressure (also differential pressure and tensile force) |
| Q | Electrical function symbol |
| R | Radiation measurement |
| S | Valves, solenoid valves, limit sw., magnetic br. |
| T | Temperature measurement |
| U | Signal processing from a control module, runtime sig. |
| V | Vibration, strain, length measurement |
| W | Electrical steam tracing |
| X | Currently not assigned |
| Y | Speed measurement |
| Z | Piping element |
Designation block 4 of the AKZ system- Equipment unit numbering
Designation block 4 comprised of 3 characters. The individual types of equipment units in each system of a count were represented by them.
Replacement with the KKS Identification System for Power Stations
The plant designation system AKZ was replaced by the KKS Identification System for Power Stations, because it did not provide a sufficient range for the designation system that was needed for the more modern power plants after 1976.
Existing power plants that still use the AKZ designation system have the one-time opportunity to convert to the KKS system or to extend their existing AKZ system with parts of the KKS Identification System.