up:: La Finka - Projects MOC
tags:: #lafinka #project #geo
skills:: #smarthome #electrical
lead:: @Niko
status:: #status/idea
start:: #y/2025/fall
estimated completion:: #y/2025/fall

Project - Overview

Complete basement geo control as a single DIN-based system with an analog, offline-first core and optional network augmentation. Any thermostat heat call will run the main loop pump, the active zone pump, and the blower. Network adds viewing state and remote override plus per-pump power measurement.

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Purpose

Provide a tidy, serviceable control panel that preserves dumb reliability (no network required) while giving us visibility and optional remote control. Consolidates legacy switches (existing furnace/air-handler safety logic (Honeywell L4064 fan/limit) ) and wiring into a clear, labeled enclosure. Includes temperature logging supply/return temps and simple scheduling

Objectives

• Analog core: 24 VAC call logic, contactors for 3 pumps, blower control selector, master power, LEDs State, Manual Switches
• Main Loop run with schedule / timer / temperature; Implement on-device hysteresis with min-on/min-off, freeze-protect, and a short anti-stagnation run.
  • Q:: Can we setup a call when hot water tap is opened?
• Thermostat heat call ORs to run main loop + Calling zone bump
• Blower follows Auto/Off/On selector
• Temperature Reading: loop supply and return temperatures with DS18B20 on Shelly Plus Add-on.
• Network layer (optional): view states, read temps, measure power on all 3 pumps, safe remote override.
• Provide a simple local UI for manual start/stop and status.

Background Info

• Current: main loop pump UPS15-58FC currenlty "always on."; two air-handler zones each use a Grundfos UP15-42F and blower governed by a Honeywell L4064 fan/limit; a motor control box handles the zone pump starts.
• Redesign provides HOA: Hand (always), Off, Auto (on any call)
• Requirement: offline-first; internet enhances dashboards/alerts only.
• Legacy 3-way toggles exist (Heat Source: Geo/Off/Oil; Blower: Geo/Off/On). Oil branch is parked.
• Hardware on hand: Shelly Plus 1PM and Shelly Plus Add-on (3× temp inputs supported).

Current Hardware

• Main Pump: UPS15-58FC (3 speed)
  • 0.55-0.75A (60-87W)
• Heater Pumps: (2) UP15-42F
  • 0.74 A (85W)

Project - Details

Scope

• Adds temperature sensing on main loop (supply/return), RC-snubbered switching of main pump, local hysteresis + schedule logic, basic logging.
• Adds status & remote switch of air handler (Pump & Blower)
• Power Monitoring of pumps

MLP - Main Line Pump
Z1P - Zone 1 Pump
Z2P - Zone 2 Pump
HOA* = Hand/Off/Auto

In (Analog Core):
Single DIN enclosure with 2 × 12" rails; 120 VAC branch protection;
Main Power Switch
3 × AC-3 Contactors (MLP, Z1P, Z2P)
24 VAC control transformer + secondary fusing
Ladder logic so any thermostat W call drives Main Loop + calling zone pump;
Blower selector (Geo/Off/On) that asserts G only when desired;
Heat Source selector (Geo/Off/Oil with Oil parked);
HOA for Main Loop;
panel LEDs for calls and pump run;
RC snubbers/MOVs across pump loads;
Class 2 vs mains separation.

In (Network Augment, non-blocking):
Shelly Pro 3EM to meter all three pumps
Shelly Pro 3 to

1. expose S1–S3 input states for Z1/Z2 calls (+ optional Blower/Main), and
2. provide safe remote add-call via its three dry relays driving interposing 24 VAC coils; optional DS18B20 temps via a separate Shelly if desired.

Out: Cloud dependence; modifying internal safety devices (e.g., L4064 fan/limit); Oil branch reactivation.

Shelly Pro picks (monitor + optional control):

• Power metering: Shelly Pro 3EM with 3 CTs to monitor the three pump circuits in one DIN unit; LAN/Wi-Fi/MQTT/HTTP; 60-day on-device history at 1-min resolution; note it has no internal relay. Shelly USA+1

• Dry-contact overrides: Shelly Pro 3 (3 potential-free relays) to parallel the 24 VAC coil feeds for Main Loop, Z1, Z2 if remote override is desired; keeps analog ladder authoritative. Shelly Knowledge Base

• (Optional) If you only care to override the Main Loop and still use Pro 3EM for metering, you can add the Pro 3EM Switch Add-On to drive a contactor; for multiple coils, Pro 3 is cleaner. Shelly Knowledge Base+1

Milestones

Major tasks or milestones within the project timeline.

A — Schematic Freeze (Analog-first)

• Finalize ladder: W bus OR, MLP-HOA, Blower selector strategy, Heat-Source selector (Oil parked), and relay-sense for WZ1/WZ2 → Pro 3 S-inputs.

B — DIN Panel Layout & Parts

• Lock enclosure/rails/duct; select AC-3 contactors (24 VAC coils) + aux, MCB, XFMR+fuse, terminals, operators/LEDs; confirm Pro 3EM CT rating/landing; assign Pro 3 S1=Z1, S2=Z2, S3=Blower or MLP-RUN. Shelly Knowledge Base

C — Procurement & Bench Build

• Order all DIN gear and labels; bench-wire rails; verify coil voltages, selector logic, LED indications, and Class 2 segregation
• Wire rails; test W-sense relays → Pro 3 inputs; prove selector truth table; verify aux-RUN contacts; label Class-2 vs mains.

D — Field Wiring & Termination

• Land pump feeds; land W/C; park Oil; route G per selector; add snubbers/MOVs; torque/label.

E — Analog Commissioning - Testing

• Zone 1 call ⇒ Z1P+MLP;
• Zone 2 call ⇒ Z2P + <LP;
• blower selector Geo/Off/On;
• Main Loop HOA Hand/Off/Auto;
• fail-safe with network absent

F — Network Bring-Up

• Install Pro 3EM CTs on the three pump hots; verify live V/A/W and 60-day history;
• install Pro 3;
• confirm S-inputs reflect WZ1/WZ2 and that relays can “add-call” via 24 VAC interposers without backfeeding. Shelly Knowledge Base

G — Dashboard

• Build a LAN dashboard (Shelly UI/HTTP/MQTT/HA) showing: Z1/Z2 call state, MLP/Z1P/Z2P RUN, and three power channels with trends; capture screenshots.

Tasks

• Add 24 VAC coil relays for WZ1/WZ2 sense; land NO→Pro 3 S1/S2 (bridge L→Sx via contact) [tasktype:: acq]
• Decide S3 use: Blower permissive (G) vs Main-Loop RUN (aux); wire accordingly
• Land Pro 3 relay outputs to interposing 24 VAC relays for safe remote add-call to MLP/Z1P/Z2P (keeps analog path authoritative)
• Install Pro 3EM + 3× CT; verify per-pump telemetry and 60-day/1-min storage [tasktype:: acq]
• Label terminal map (TB-LINE; TB-LOAD-MLP/Z1P/Z2P; TB-CTRL W/C/WZ1/WZ2/G; TB-AUX RUN; TB-NET S1/S2/S3)
• Commission analog logic; then verify Pro 3 inputs change with real thermostat calls and that Pro 3EM wattage aligns with contactor RUN
• Build dashboard cards: “Zone Calls,” “Pump RUN,” “Pump Power (3EM)” with alert thresholds
• Export Shelly configs/JSON; attach panel photos in note

DIN Enclosure & Rails

• Enclosure: Polycarbonate NEMA 4X, ~16×14×7 in with 2 stacked DIN rails (top: power; bottom: control), door for 22 mm operators and LEDs. - DIN rails: two × 12″ rails inside single enclosure.

One-Line Power (ASCII)

[Service 120VAC] → Main Power Switch (lockable) → 1P MCB (pump branch)
├─→ Contactor MLP (Main Loop Pump, 2P AC-3) → TB-LOAD-MLP → Main Loop Pump ├─→ Contactor Z1P (Zone1 Pump, 2P AC-3) → TB-LOAD-Z1P → Zone1 UP15-42F ├─→ Contactor Z2P (Zone2 Pump, 2P AC-3) → TB-LOAD-Z2P → Zone2 UP15-42F └─→ 24VAC Control XFMR (40–60VA) → TB-CTRL-24V (W bus, C common) PE/Neutral bussed to each load; MOV/RC snubber across each pump load (L–N).

Control (24 VAC) — Ladder (ASCII)

Notes on blower

• Preferred: keep L4064 fan/limit to gate the blower; in Blower=GEO, you assert G on MAIN_CALL so the handler has permission, but L4064 still delays fan until coil/plenum is warm. In ON, G is forced regardless of call. In OFF, G is inhibited.

Network Augmentation (no control dependency)

• Power measurement: 1× Shelly EM (2-CT) on Z1P+Z2P branch hots, plus 1× Shelly Pro 1PM on MLP branch; or 2× EM to cover all three if you want identical meters.
• Status: Use each contactor’s aux NO into a small input bridge (e.g., Shelly Pro 2 or ESP32 optos) to view RUN states; or map from EM power > threshold.
• Temperatures (optional): One Shelly Plus Add-on with DS18B20 on main supply/return.
• Remote override: Add a Shelly Pro 1 (dry) to drive a 24 VAC slim relay whose NO contact parallels KOR NO into the MLP coil path, and optional parallels for Z1P/Z2P. Remote never interrupts the analog path; it only “adds a call.”

Front Panel (door operators, 22 mm)

• Main Power Switch (lockable). - Heat Source Selector (Geo/Off/Oil, with Oil parked). - Blower Selector (Geo/Off/On). - Main Loop HOA (Hand/Off/Auto). - LEDs: Call Z1, Call Z2, Main Pump ON, Z1 Pump ON, Z2 Pump ON. - Engraved legends matching internal terminal IDs.

Project - Resources

Budget

TBD (Phase 1 expected low — primarily enclosure/consumables; Phase 2 adds sensors/metering).

Materials & Tools (DIN bill of materials — analog core)

• Polycarbonate enclosure 16×14×7 in with two 12″ rails [tasktype:: acq]
• Main power switch-disconnect, lockable, door-handle style (motor-rated) [tasktype:: acq]
• 1P MCB (pump branch per nameplate) [tasktype:: acq]
• 3× 2-pole contactors (AC-3, 24 VAC coils) + 3× aux NO blocks [tasktype:: acq]
• 24 VAC control transformer 40–60 VA + secondary fuse holder [tasktype:: acq]
• 3× slim control relays (24 VAC coils) for KZ1, KZ2, KOR [tasktype:: acq]
• 3× RC snubbers or MOVs (across pump loads) [tasktype:: acq]
• 22 mm operators: Heat Source selector (3-pos), Blower selector (3-pos), MLP HOA (3-pos), LEDs (Z1 Call, Z2 Call, Main ON, Z1 ON, Z2 ON) [tasktype:: acq]
• Feed-through terminal blocks for L/N/PE and Class 2, markers, end plates, wire duct, ferrules [tasktype:: acq]

Network layer (optional now or later)

• Shelly EM (2-CT) + CTs; plus 1× Shelly Pro 1PM or a second EM to cover all 3 pumps [tasktype:: acq]
• Shelly Pro 1 (dry) + slim 24 VAC relay for remote add-call [tasktype:: acq]
• Shelly Plus Add-on + DS18B20 probes for main loop supply/return [tasktype:: acq]
• [ ]

Materials & Tools

• Pilot LED (120 VAC panel Light) Place in line with RC snubber
• Shelly Plus 1PM (host) [tasktype:: acq]
• Shelly Plus Add-on [tasktype:: acq]
• DS18B20 stainless probe ×2 (3-wire) + paste + insulation wrap [tasktype:: acq]
• RC snubber (0.1 µF X2 275 VAC + 100 Ω, series R-C) [tasktype:: acq]
• Small surface box with strain reliefs, receptacle pigtails, ferrules, labels [tasktype:: acq]
• Optional MOV 275 VAC and clamp for line protection [tasktype:: acq]
• Hand tools, multimeter, non-contact voltage tester, zip ties, Armaflex tape [tasktype:: acq]
• 24 VAC coil relays ×2 (SPST/DPDT, with sockets or enclosed) [tasktype:: acq]
• Low-voltage enclosure, DIN-style base or relay sockets, labels [tasktype:: acq]
• M5 ESP32 dev board + 5 V PSU (wall wart) [tasktype:: acq]
• 2-channel non-invasive CT energy monitor (for two 120 VAC zone pumps) [tasktype:: acq]
• Low-voltage cable (18/2) for W/C taps and dry-contact runs; ferrules; heat-shrink [tasktype:: acq]

Equipment

• UPS15-58FC main circulation pump (existing)
• UP15-42F zone pumps ×2 (existing)
• Honeywell L4064 fan/limit (existing)

References / Examples:

• Shelly Plus 1PM knowledge base and wiring examples (inductive load + RC snubber)
• Shelly Plus Add-on pinout and DS18B20 wiring
• Grundfos UPS15-58FC and UP15-42F nameplate specs for sanity checks
• Relay-sense pattern for 24 VAC calls (W–C coil, dry-contact to logic)
• ESPHome binary_sensor + GPIO pull-ups example
• CT-based runtime/watts correlation methods

Questions / Unknowns:

• Preferred set points: T_on and T_off targets for return (or supply) hysteresis?
• Freeze-protect threshold to force ON (e.g., 40 °F return)?
• Anti-stagnation run window acceptable at 03:00 for 5 min?
• Exact surface box location and receptacle re-feed path; any clearance constraints?
• Third sensor in Phase 1: keep spare vs. add ambient or well-return now?
• Phase 2: CT-based metering vs. using an additional 1PM as “meter-only” on each zone pump branch?
• Confirm W and C terminal availability in the motor control box per zone - Do we want any summer lockout to also mask W at the relay coils (Phase 3 idea) - Preferred dashboard: minimal ESPHome page vs. HA panel - Exact CT model preference (split-core vs. solid-core; 20–50 A range) - Any need to export data to the La Finka intranet

Documentation and Media

Photos and Videos:

Add install photos of surface box, probe mounting, wiring before/after.

Documents:

Add wiring sketch, terminal map, and exported Shelly settings (JSON/script).

Technologies

• Shelly Plus 1PM (local web UI, schedules, scripting)

• Shelly Plus Add-on (DS18B20 1-Wire)
• DS18B20 probes
• RC snubber (R-C in series across load)
• 24 VAC coil relays (call sensing)
• M5 ESP32 with ESPHome (LAN-only)
• 2-channel CT energy monitor (zone pumps)
• Optional: Home Assistant/MQTT (local)

One-Page Terminal Map

Power & Loads

24 VAC Control (Class 2)

Coils & Interlocks

Network Augment (Shelly Pro)

Operators (door-mounted, 22 mm)

Indicator LEDs

Collaboration and Participation

How to Get Involved

Electrical helper for install day; photographer to document probes and wiring; reviewer to validate acceptance tests and capture baseline logs. Volunteers welcome to shadow for Phase 2 sensing add-ons.

Created: 250929-21:51

Updated: 251024-10:49