Are you working in the electrical contracting field?
Are you designing electrical systems?
Are you interested in learning about the different electrical installations On-Site?
Are you working in the MEP field?
You must read this post if your answer is Yes to any of the above questions.
Firstly, let us know what the electrical panel schedule is.
Before telling you the answer, let us imagine that you are supervising an electrical team together.
This team is responsible for installing electrical containment (either embedded or exposed conduits) within a specific zone. For simplicity, I will assume the area is a basement floor, and the installations will be exposed pipes.
These electrical installations will surely include wiring for lighting and small power systems.
You will need to install 20 lighting fixtures in the basement and ten weatherproof socket outlets.
You will know these 20 lighting fixtures are looped together on the same circuit number or connected to different circuits from the electrical lighting shop drawing.
Let us say these 20 lighting fixtures will be connected to a lighting distribution panel named LP-B-01, and the number of circuits is 5 & 8.
So, the circuit numbers will be LP-B-01/5 & LP-B-01/8, respectively.
LP means Lighting panelboard, B means Basement floor, 01 is the panelboard number, and 5 or 8 is the circuit number.
But to give proper instruction for your electrical team to proceed with the installations, you need to know the cross-sectional area of the wires of both circuits 5 & 8.
Plus, you need to know the conduit size, type, EMT, RGS, …etc.
Moreover, to check and confirm the electrical load of a circuit, especially during the shop drawing preparation stage, you need to know each outlet’s wattage.
You will find the answer to the above questions and more in the electrical panel schedule drawing.
The same applies to the outlets of the small power circuit.
What other information can you get from the electrical panel schedule?
From the attached photo for a sample of an electrical panel schedule, you can see that we can know the following information:
01- The panel name
02- The service voltage to this panel. 230/400, or 110220,…etc.
03- The number of ways that exist in this panel and the frequency of the network connected to this panel.
04- The panel location, like the floor and room names.
05- The mounting type of the panel, surface mounted, recessed mounted, semi-flush,..etc.
06- This panel is powered by which panel/source?
07- The cross-section area of the feeder cable to this panel.
08- The number of outlets connected on the same circuit. (not all designers put this information)
09- The cross-section area of the circuit’s wires/cable.
10- The ampere rating of the main circuit breaker of the panel.
11- The type of the main circuit breaker of this panel, MCB, MCCB, or any other type.
12- The feeder entry is a top entry or bottom entry, and its cable type.
13- The ampere rating of each circuit’s circuit breaker exists in this panel.
14- The type of breakers of each branch circuit. Whether it’s an MCCB, MCB, ELCB, RCCB…etc.
Where:
MCCB: Moulded Case Circuit Breaker.
MCB: Miniature Circuit Breaker.
ELCB: Earth Leakage Circuit Breaker
RCCB: Residual Current Circuit Breaker
15- The type of loads on each circuit, whether single-phase or three-phase loads.
16- The color of the wires/circuits of each phase, whether they will be Red, Yellow, Blue, Black, or they will be Brown, Black, Grey, or Blue.
Note:
In the Old British Standard, RYB, the neutral will be black, while in the newest British/IEC Standard (BBG), the neutral color is blue, and the phases’ colors are Brown, Black, and Grey, respectively.
17- The number of available spare breakers inside this panel.
18- The number of available spaces inside this panel.
19- The total connected load on each phase of the panel.
20- The total connected load on the panel.
21- The demand factor of this panel.
22- There’s a phase of balancing on this panel or not.
23- Some designers also put the circuit’s total length from the panel board to the last outlet.
From the previous, you can conclude why the electrical panel schedule is one of the most important drawings in electrical systems.
Now I will give you some bonus points to help you avoid many problems during the panel board’s installation process.
A- You need to make sure the panel’s location in the electrical panel schedule is the same as the electrical system layout and the architecture layout.
B- You need to ensure the number of outlets connected to the same circuit is identical between the electrical panel schedule and the system layout.
C- You must have enough spare breakers & space as per your project’s specifications.
D- The more breakers you have in the panel, the more size or space is required for the panel board.
E- Try to achieve a phase balance between the three phases as much as you can.
F- Before ordering cables or wires for any circuit, you need to confirm their colors and cross-sectional areas per the latest approved electrical panel schedule.
G- During the dressing of electrical wires and cables inside the panel, ensure the latest approved panel schedule is attached to the panel board; without it, the electrician can’t provide proper tagging for each circuit.
H – If you are a contractor and need to order wires/cables based on the total length available in the approved panel schedule, you need to cross-check the circuit’s full length against the CAD file of the system layout.
This is mainly for electrical lighting circuits, because the designer who prepared this panel schedule may have calculated the circuit length based only on the horizontal distance and didn’t account for the wire or cable required for each outlet.
(Free videos) The practical explanation for the components of the electrical panel On-Site
(Free videos) Ring Main Unit ” RMU ” – Explanation for Its Components Practically On-Site
For example:
Suppose you have lighting fixtures in a false gypsum ceiling, and the distance from the false gypsum ceiling to the concrete soffit is 60cm.
So, for each electrical lighting outlet, you need to consider an additional length for the wires as follows: 60cm+60cm+additional length to terminate these wires to the fixture (ex, 30cm).
So the total length = 60 + 60 + 30 + 30 = 180 cm for each wire/cable connected to this lighting outlet.
I hope you find this article interesting. If yes, kindly leave a comment to motivate us, and share this article with your connections.
Here is a list of the electrical tools that will be required to complete the termination of the panel:
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Please click on the next button to get the complete editable file of different MEP method statements and other method statements.
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If You would like to learn more about the practical installations of the different MEP systems on-site, so have a look at our free MEP Mini-Course
Here are links for my other posts related to the MEP installations on-site:
Knockout Hole Punch – How to use it in 5 easy steps
Torque Wrench – Your Best Guide in 4 Minutes
Electrical Panels – No.1 Guide in their Practical installations On-Site
Top 10 important tools with the electrician in Infrastructure Works
The Common 7 MEP Mistakes & Solutions in the Construction Projects- Your Best Guide
Your Easy BMS Guide “Building Management System” in Projects – No.1 Guide
Your Easy Guide in Understanding the Fire Alarm System from A to Z, 100% you will be satisfied
The Most Important 10 PPE in Construction Projects
Your No.1 Guide for better understanding MEP Infrastructure Networks in construction projects
No.1 Easy Guide about VRF & VRV Systems
