What TN-S, TN-C-S, TT and IT earthing mean for fault current and protective devices, with the same circuit worked through on TN-C-S and TT.
TN-S vs TN-C-S vs TT Earthing: Systems Explained (Plus IT) Read More »
How to size supply ducts with the equal friction method, check velocities for noise, count fitting losses and calculate the index run that selects the fan, with a fully worked office floor branch.
Duct Sizing Guide: Equal Friction, Fittings and the Index Run Read More »
The essentials of a cooling load calculation – heat gain versus cooling load, solar and shading, internal and latent loads, coil load and zone diversity – with a worked west office and a full office floor.
Cooling Load Calculation Basics: Solar, Internal and Latent Loads Read More »
How to design a clean agent system for a server room to NFPA 2001: design concentration, agent quantity, safety limits, discharge and hold time, enclosure integrity and venting.
Clean Agent System Design for Server Rooms (NFPA 2001) Read More »
How to size a cable for both current capacity and voltage drop using mV/A/m values, with typical limits and a worked sub-main plus final-circuit example.
Cable Sizing for Voltage Drop: Formula, Limits and Worked Example Read More »