Practical Power Plant Engineering. Zark Bedalov
equipment rating requirements. The specification for a particular piece of equipment can be updated from project to project with some minor changes. It is the data sheet that changes in a big way as the application and ratings may be completely different from project to project.
Hopefully, the new specifications will be similar to those of your previous projects. Often, one can change the project name and the spec number and then revise the data sheet to suit the equipment you need for your new project. Try not to repeat yourself in the documents. Sooner than you think, someone will call and ask you: “What do you want: 1000 A breaker written in the specification or 1200 A breaker listed in the Data Sheet.” If you want to talk about the breaker in the specification, just note: “For the ratings, refer to the Data Sheet.”
From project to project, try to maintain the same ID number for the same design product, if the project permits it. For instance:
Specification and data sheet, respectively, for MCCs on project ABC: ABC – xxx – TS31 – DS31
Specification and data sheet, respectively, for MCCs on project XYZ: XYZ – xxx – TS31 – DS31
Try to group the documents for the type of equipment and services. Leave some gaps as there are differences in scope from project to project. When you are dealing with equipment like MCCs located in various different parts of a plant, write a common spec with several data sheets added to it for different areas.
Here is a list of specifications from a recent project in Minnesota on a 55 MW power plant using turkey litter as fuel:
1 Electrical contribution to mechanical engineers' specifications.
| TS01 | Electrical requirements for mechanical equipment |
| TS02 | Electrical requirements for 480 V motors up to 200 kW |
| TS03 | Electrical requirements for medium voltage (MV) motors over 200 kW |
1 Main power distribution
| TS11 | Switchyard equipment and hardware |
| TS13 | Large transformers |
| TS14 | Standby diesel generator |
| TS15 | Relay protection panels |
| TS17 | 13.8 kV transformers |
| TS21 | 13.8 kV switchgear |
1 Plant equipment
| TS23 | MV motor controllers |
| TS24 | MV VFDs |
| TS31 | 480 V MCCs |
| TS32 | 480 V VFDs |
| TS33 | Unit substations and low voltage (LV) switchgear |
| TS35 | Station battery and chargers |
| TS36 | Uninterruptible power supply (UPS) equipment and panels |
| TS37 | Rigid bus ducts |
| TS38 | Cable bus ducts |
| TS39 | Lighting and distribution panels |
| TS40 | Power and control cables |
| TS41 | Plant heat tracing panels and hardware |
1 Services and plant installation
| TS43 | Plant CCTV |
| TS44 | Plant public address |
| TS45 | Plant telephones and data |
| TS51 | Plant fire detection and suppression system |
| TS52 | Plant heat tracing |
| TS54 | Overhead distribution lines |
| TS55 | Switchyard installation |
| TS57 | Plant installation |
1.2.6 Equipment Numbering
There are a number of methods on how to number the equipment. Some clients may have their own numbering system for all of their projects. The numbering is generally done by the mechanical department, except for the purely electrical equipment, which is numbered by the electrical group. The most popular numbering systems are the intuitive systems, as follows:
Example: 20 PU 007; Area 20; PUmp sequence number: 007. The pump number is also given to the associated motor.
The plant process areas may be given the specific area designations:
00: For a general site, including the main substation
10: Crushing
20: Conveying
30: Milling
40: Flotation, etc.
For the equipment, assign intuitive designations as follows:
PU, pump; SP, sump pump; TK, tank; CR, crane; AG, agitator; VF, vent fan; RF, roof fan; LP, lighting panel; HR, heater; CV, conveyor; TR, transformer; CY, cyclone; etc.
The sequence is from 001 to 999. The sequence numbering may restart from 001 for each area.
The numbers do not have to be consecutive. The sequence number 001 may start from the basement, 101 on the first level, etc., to better describe the equipment location.
Be consistent and make sure the pumps are sequenced in pairs: 001/002, 103/104, the odd number is, for instance, on the left side approaching the motors.
Cables are generally numbered and defined by the loads and not the MCC sources. Some companies insist that cable numbers include indications of the source (the MCC bucket) and the destination (load). Standardize control cables for the common hardware such as pushbuttons by using consistent cable C suffixes, programmable logic controller (PLC) connections. For instance, the cables for the pump 40 PU 003 are labeled:
40 PU 003 P: For the motor power cable.
40 PU 003 C1: For the control cable to PLC equipment.
40 PU 003 C2: For the control cable to the Push Button station.
40 PU 003 C3: For the control cable to the field level switch or other sensor.
Make sure the numbering is consistent for all plant motors. This will allow for