Reference · technical diagrams
Piping schematics, NEC wiring layouts, and HVAC system diagrams. Select a diagram to zoom, print, or export it as a PNG or PDF. These are educational schematics — confirm canonical detail and the in-force edition with your AHJ.
Plumbing
P-Trap & Vent (Trap Seal) A vented P-trap holding a 2–4 in liquid seal that blocks sewer gas, with the trap arm running to a sanitary tee and dry vent.
Plumbing
DWV Stack, Branch & Cleanouts Fixture branches into a soil stack that vents through the roof and turns into the building drain/sewer, with cleanouts at the stack base and sewer junction.
Plumbing
Water Supply Distribution (PRV, Hot/Cold) Service through the meter and pressure-reducing valve feeding cold branches and a water heater whose hot trunk serves the fixtures.
NEC Wiring
120V Branch Circuit (Receptacles) A panel breaker feeding receptacles with hot (ungrounded), neutral (grounded), and equipment-grounding conductors.
NEC Wiring
Service Grounding & Bonding Main bonding jumper tying the neutral bus to the enclosure ground, with the grounding-electrode conductor to a ground rod and metal water pipe.
NEC Wiring
3-Way Switch Loop Two 3-way switches controlling one luminaire from two locations via a common, two travelers, and a switch leg.
NEC Wiring
Service Panel Layout (Main & Buses) A load center with a main breaker feeding two hot bus stabs, single-pole branch breakers, a 2-pole 240V breaker, and separate neutral and ground buses.
NEC Wiring
240V Double-Pole Circuit (NEMA Receptacle) A 2-pole breaker on both hot legs feeding a four-wire cable to a NEMA 14-50/14-30 receptacle, with brass hot, silver neutral, and green ground terminals.
NEC Wiring
Water & Gas Piping Bonding A bonding conductor from the service ground bus to a clamp on the metal cold-water pipe, a jumper bridging the water meter, and the gas piping bonded to the grounding system.
HVAC
Split System (Condenser & Air Handler) Outdoor condensing unit connected to an indoor air handler by an insulated suction line and a liquid line, with the metering device at the coil.
HVAC
Forced-Air Supply & Return Ducting Furnace/air handler drawing return air through a filter and pushing supply air through a plenum and trunk to room registers.
HVAC
Hydronic Boiler Loop Boiler, circulator pump, zone emitters, expansion tank, and relief valve forming a closed hot-water heating loop.
Solar
Grid-Tied PV System A PV array on the DC side feeding a string inverter, then an AC backfeed breaker in the main service panel, the utility meter, and the grid.
Solar
Battery Backup & Rapid Shutdown A hybrid inverter tying a PV array and an LFP battery to a critical-loads subpanel, with an island boundary to the grid and a module-level rapid-shutdown boundary at the array.
Low Voltage
Structured Cabling Channel (TIA) A patch panel and equipment cord feeding a horizontal run to a keystone outlet and work-area cord, showing the ≤90 m permanent link inside the ≤100 m channel.
Low Voltage
PoE Power Budget Power-sourcing equipment (endspan switch or midspan injector) delivering power over twisted pair to a powered device, with cable loss between the PSE and PD ratings.
Fire & Fabrication
Wet-Pipe Sprinkler Riser Underground supply through an OS&Y gate valve and alarm check valve with a waterflow switch, rising to a cross main and branch lines with pendent sprinklers; an FDC tees in and a main drain sits at the base.
Fire & Fabrication
Fire Alarm Circuits (IDC/SLC & NAC) A fire alarm control panel running an initiating/signaling line circuit to detectors and a pull station, and a separate notification appliance circuit to horn/strobes, each terminated with an end-of-line resistor.
