What is a Sub-Distribution Panel (SDP)? How does it differ from an ADP?
In electrical projects, two concepts that are most frequently confused are the main distribution panel and the secondary distribution panel. Both distribute energy, but their locations within the facility and the loads they handle are completely different. This article clearly explains the difference.
What is a Sub-Distribution Panel?
Sub-distribution panel (SDP), A distribution panel is an intermediate panel that carries energy from the main distribution panel to areas near the end-use points. Typically, a distribution panel is found on every floor of a building and in every production section of a factory.
The aim is to bring the energy closer to the point of consumption; thus reducing cable cross-sections, decreasing voltage drop, and limiting the area affected in the event of a fault.
Differences Between ADP and TDP
| Criterion | Main Distribution Panel (ADP) | Secondary Distribution Panel (SDP) |
|---|---|---|
| Location | The facility's energy input | Within a floor, section, or area |
| Nutrition | Transformer or network | ADP |
| Current level | High (800-6300 A) | Lower (63-630 A) |
| Short circuit withstand capability | Very high | Intermediate level |
| Medicine | Standing cabin | Wall-mounted or freestanding |
| Fault effect | All facilities | Only the relevant region |
What should be considered when choosing a TDP (Turkish Democratic Party)?
- Selectivity: The circuit breaker in the TDP must trip before the main circuit breaker in the ADP. Otherwise, a minor fault will black out the entire plant.
- Spare arm length: Empty modules should be left for future circuits to be added.
- Leakage current protection: For safety reasons, 30 mA residual current devices should be planned.
- Environmental conditions: The appropriate IP rating should be selected for humid or dusty areas.
- Labeling: The panel should clearly indicate which area each circuit supplies; this reduces maintenance time.
Why is a Good Editing Important?
In installations where ADP and TDP panels are not dimensioned to match, two typical problems occur: either minor faults shut down the entire system (selectivity failure), or the secondary panels are insufficient, leading to overheating and voltage drops. Both can be prevented with calculations made during the design phase.
A Solution Suitable for Your Project
At ElektroPanel, we manufacture main and secondary distribution panels in a coordinated manner, using an infrastructure that conforms to IEC 61439 type testing standards. Our lighting and secondary distribution panels page you can review or You can get a quote by sharing your single-line diagram..
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