Electrical for smart home
What to know about the power side: panels, groups, cables, UPS, generator. Smart home cannot work without good electrical
Electrical — the foundation of a smart home
Without a quality power part, a smart home does not work. KNX, Lutron, Crestron are an add-on over conventional electrical. If the panel is assembled poorly, there is no redundancy, the wiring does not match the loads — no buses and panels will save it.
Electrical is the longest and most hidden stage. Mistakes in the walls cannot be fixed later without major repairs. Therefore, the design and installation of the power part is done first and most carefully.
Main distribution board (MDB)
The MDB is the brain of the power part. The input from the metering panel comes here, here are the input circuit breakers, RCDs, voltage relays, selective protection. From the MDB go lines to floor or apartment panels.
In a good MDB: ABB, Schneider Electric, Hager or Legrand. Automation with manual and automatic control. Each line is labeled, numbered, has a single-line diagram.
If there is a backup (generator, UPS) — the ATS (automatic transfer switch) is connected here. Switching time is fractions of a second, so that the smart home continues to work when external power is turned off.
Cables and groups
Copper cables — VVGng-LS (flame retardant, low smoke) or NYM. Cross-section — by load, with a margin of 20-30%. Each group is a separate circuit breaker in the panel, a separate line.
Low-current lines (KNX, Ethernet, signal) — in separate routes, not in the same cable channel with power ones. Minimum 100 mm between power and low-current cables. Crossing — at 90°.
Socket groups and lighting groups are different. For wet rooms (kitchen, bathroom, sauna) — separate lines with 30 mA RCD. For powerful consumers (oven, hob, air conditioner) — separate lines with a circuit breaker of the appropriate rating.
Grounding and lightning protection
Grounding is mandatory — it is safety and stable operation of electronics. Grounding circuit around the perimeter of the building, resistance — no more than 4 ohms for TN-C-S.
Lightning protection is a separate system. Lightning rods on the roof, down conductors along the walls, grounding. Do not confuse with protection against impulse overvoltages (SPD) — these are devices in the panel that protect sensitive electronics (KNX, servers, AV).
UPS and generator
Uninterruptible power supply is critical for a smart home. UPS (APC, Eaton, CyberPower) keep the router, KNX/Lutron/Crestron controllers, servers, video surveillance cameras running for 15-60 minutes.
Generator (diesel, gas) — for a long-term outage. Auto-start, ATS in the panel, power — with a margin of 20% from peak load. Switching time — up to 30 seconds.