Panel Schedule

A Panel Schedule is a document or table that provides detailed information about the electrical panel, such as the circuits it supplies, their ratings, protective devices, and load information. It is typically created for distribution panels, main distribution boards (MDBs), or sub-distribution boards (SDBs) in residential, commercial, and industrial buildings. The panel schedule helps electricians, engineers, and maintenance personnel ensure proper power distribution and safety within the electrical system.

Key Components of a Panel Schedule:

A typical panel schedule includes the following details:

1-Panel Identification:

1. Panel Name/Number: A unique identifier for the panel (e.g., "Panel A," "Main Distribution Panel," or "P1").
2. Panel Location: The physical location where the panel is installed (e.g., "Ground Floor," "West Wing").

2-Incoming Power Information:

1. Voltage: The voltage rating of the incoming supply, typically in volts (e.g., 120/208V, 240V, 400V, 11kV).
2. Phase: The number of phases in the electrical system, e.g., single-phase or three-phase.

3-Breaker Information:

1. Breaker Number: A unique identifier for each circuit breaker in the panel (e.g., "CB1," "CB2").
2. Breaker Type: The type of circuit breaker (e.g., thermal-magnetic, electronic).
3. Breaker Rating: The current rating of the breaker, typically in amperes (A). It defines the maximum current the breaker will allow before tripping (e.g., 15A, 20A, 100A).
4. Breaker Size: The size or rating of the protective device, which should match the size of the wire and load (e.g., 20A for lighting, 30A for small equipment).

4-Circuit Information:

1. Circuit Number: The identifier for each individual circuit (e.g., "Circuit 1," "Circuit 2").
2. Circuit Description: A description of the load connected to the circuit (e.g., "Lighting," "HVAC," "Motors," "Receptacles").
3. Load Type: Specifies the type of electrical load connected to the circuit (e.g., resistive load, inductive load, etc.).

5-Ampacity (Current Rating):

1. This is the amount of current the circuit is designed to carry, typically in amperes (A). It is based on the breaker rating and the wire size.
2. For example: A lighting circuit may be rated for 15A while a larger HVAC circuit might be rated for 30A.

6-Load Information:

1. Connected Load: The total load connected to each circuit, typically measured in watts (W) or kilowatts (kW). This helps estimate the power demand on each circuit.
2. Demand Load: The estimated actual load based on expected usage, often calculated as a percentage of the connected load.
3. Power Factor: The efficiency of the electrical system (usually for inductive loads like motors, which may have a power factor less than 1).

7-Phase and Neutral (for Three-Phase Systems):

1. Phase Assignment: In a three-phase system, circuits are typically distributed across phases to balance the load. The schedule may indicate which phase each circuit is connected to.
2. Neutral: Whether or not the circuit requires a neutral wire for return current.

8-Grounding:

1. Indicating whether a grounding conductor is provided for each circuit.

9-Other Information:

1. Interrupting Rating: The maximum fault current that the breaker can safely interrupt (usually for industrial panels).
2. Remarks: Additional information, such as special instructions or warnings (e.g., “Not to exceed 80% of breaker rating,” or “Dedicated circuit for server room equipment”).

Example of a Panel Schedule Format

Breaker No.	Circuit Description	Load Type	Amp Rating	Voltage	Phase	Connected Load (kW)	Demand Load (kW)	Power Factor	Breaker Type	Remarks
CB1	Lighting	Resistive	15A	120V	Single	1.5	1.2	1.0	Thermal-Magnetic
CB2	HVAC System	Inductive	30A	240V	Single	5.0	4.5	0.9	Thermal-Magnetic	Dedicated circuit
CB3	Receptacles (General)	Resistive	20A	120V	Single	3.0	2.5	1.0	Thermal-Magnetic
CB4	Main Equipment Panel	Inductive	50A	240V	Three-phase	15.0	12.0	0.8	Electronic	Critical load
CB5	Emergency Lighting	Resistive	10A	120V	Single	0.5	0.5	1.0	Thermal-Magnetic

Steps to Create a Panel Schedule:

1-Gather System Information:

• Identify the electrical load to be connected to the panel (lighting, machinery, HVAC, receptacles, etc.).
• Obtain the power ratings of all connected equipment (amps, watts, kilowatts).
• Determine the appropriate circuit breaker sizes for each load.

2-Calculate Loads:

• For each circuit, estimate the connected load and the demand load. The demand load will often be less than the full connected load, based on expected usage.

3-Assign Breakers:

• Choose the appropriate breaker size and type for each circuit. Ensure the breaker rating is in line with the ampacity of the conductors and the connected load.

4-Document Circuit Information:

• For each circuit, list its description, phase, breaker type, amp rating, and other relevant details.

5-Review and Check for Balance:

• If you're dealing with a three-phase system, ensure the loads are balanced across the phases to avoid overloading one phase.

6-Finalize the Panel Schedule:

• Once all circuits and breakers are assigned, compile the information into a table or spreadsheet format. Include any necessary remarks, notes, or safety instructions.

Importance of a Panel Schedule:

• Safety: Ensures that circuit protection devices are correctly sized and configured to protect wiring and equipment from overloads and faults.

• Compliance: Helps comply with electrical codes and standards, such as the NEC (National Electrical Code) in the United States or similar codes in other countries.

• Maintenance: Assists maintenance personnel by providing clear details about the circuits, making troubleshooting easier when issues arise.

• Load Management: Helps manage electrical loads to avoid overload conditions by ensuring circuits are adequately sized and not drawing more current than their rated capacity.

Attention

A Panel Schedule is an essential tool for designing, operating, and maintaining an electrical distribution system. It ensures safe and efficient operation by clearly detailing circuit protection, load requirements, and electrical characteristics. Creating a proper panel schedule helps improve safety, efficiency, and compliance with electrical codes.

Let me know if you'd like help with creating a panel schedule or understanding any part of the process!