Configuring Siemens LOGO! 230RC for Exterior Lighting Control

Overview

Exterior lighting projects using a Siemens LOGO! 230RC logic module require attention to three engineering layers that are often overlooked in residential-style installations: input voltage selection, relay output derating, and expansion module addressing. The LOGO! 230RC (a 230 VAC powered base unit with relay outputs) is well suited to mains-driven lighting circuits because it shares the same L/N supply as the lighting load, eliminating the need for an extra 24 VDC power supply. The trade-off is that the on-board relay contacts are not designed to switch the full branch-circuit current of a multi-fixture lighting run; they must drive a contactor or impulse relay, which in turn handles the lighting load.

This reference covers the engineering decisions for a typical three-stage exterior lighting system:

1. Scheduled on/off control via the LOGO! weekly/yearly timer blocks.
2. Presence-triggered bright-up using a 230 VAC PIR or radar sensor on a digital input.
3. Continuous dimming or stepped dimming using a 1–10 V analog output or DALI/KNX gateway.

It also documents expansion with the LOGO! DM8 230R, LOGO! DM16 230R, and the mixed-voltage LOGO! DM8 24R modules, and provides the maximum system architecture permitted by firmware 8.x and 0BA8 base modules.

Prerequisites

• LOGO! 230RC base module (LOGO! 8 family, MLFB 6ED1052-1MD08-0BA1 or 0BA8 standard 6ED1052-1FB00-0BA8). Verify on the device label.
• LOGO! Soft Comfort V8.x or higher for offline program development. The current release is available from the Siemens Industry Online Support portal.
• A 230 VAC mains distribution that includes a dedicated MCB (typically 10 A Type C or Type B) for the LOGO! supply and a separate MCB for the lighting load.
• Sensor data sheet specifying output type (volt-free contact, 230 V switched, or low-voltage DC).
• Contactor or impulse relay with coil voltage matched to the LOGO! relay rating and contact rating ≥ load current.

Selecting the Right LOGO! Base Module

For 230 VAC lighting environments the practical base module choices are:

All 230 V base modules expose the same input circuit topology: each digital input (I1–I8) detects 115/230 VAC between the input terminal and N. Sensor switching must therefore present an AC voltage between the input and N, not a volt-free contact, unless the base unit is a 24 V variant.

Power Supply and Earth Connection Considerations

The LOGO! 230RC accepts 115 VAC and 230 VAC on terminals L1 and N. The PE conductor from the supply must be terminated in the upstream distribution board, but it is not terminated at the LOGO! module. The plastic housing carries no user-accessible earth bonding point; the device relies on reinforced insulation to satisfy Class II requirements. The same applies to every DM8/DM16 230R expansion: the earth from the lighting circuit must continue through the contactor and the lighting load, bypassing the LOGO! entirely.

Wiring the Digital Inputs for the Motion Sensor

For a 230 VAC PIR sensor (typical model families: Steinel IS 1, ESYLUX RC, Theben theLeda), connect the switched output (commonly a brown or black conductor) to a LOGO! digital input (I1–I8) and the neutral (blue) to the LOGO! N terminal. The sensor's L supply is taken from the same MCB that feeds the LOGO! L1.

If the sensor uses a volt-free (relay) output, confirm whether the contact is rated for 230 VAC switching. Some 24 V sensors cannot be wired directly to a 230 V input because the LOGO! input threshold is around 79 VAC (for 230 V inputs) and a 24 V closed contact will never be recognised. In that case, add an interposing 24 VDC relay or use a 24 V base module on the affected input.

Relay Output Limitations and Contactor Sizing

Each LOGO! relay output is rated as follows (manufacturer data, base module 230RCE/230RCo):

• Resistive load: 10 A at 230 VAC
• Incandescent / halogen: 1,000 W
• Fluorescent with electronic ballast: 10 × 58 W
• LED driver switching (inrush-limited): typically 6 A continuous
• Mechanical endurance: 10 million cycles
• Electrical endurance at full load: 100,000 cycles (derate for inductive or capacitive loads)

Although a single LED fixture may fit within the 10 A rating, the contact endurance of a relay that is cycled multiple times per evening by a motion sensor is severely reduced. Use a contactor sized for the load:

Three-phase apparent power (for multi-circuit or 3-phase contactor coils):

kVA = sqrt(3) × V_LL × I_line / 1000

Single-phase apparent power (typical lighting contactor coil):

kVA = V × I / 1000

Wire the LOGO! output (Q1–Q4) to the contactor coil terminal A1, link A2 to N, and route the lighting MCB through the contactor's main contacts (L → contactor in → contactor out → lighting load L, with N and PE handled separately).

Wiring Topology (Inline SVG)

Step-by-Step Wiring Procedure

1. Isolate the supply. Lock out / tag out the upstream MCB. Verify zero voltage with a CAT III 600 V meter.
2. Mount the LOGO! and contactor on a DIN rail inside a suitable IP54 (outdoor) or IP20 (indoor) enclosure. Maintain ≥ 10 mm clearance above and below for ventilation.
3. Terminate the supply. L → LOGO! L1, N → LOGO! N. Do not connect PE to the LOGO!.
4. Terminate the sensor. Sensor L → MCB load side; Sensor N → LOGO! N; Sensor switched L out → LOGO! I1.
5. Terminate the contactor coil. LOGO! Q1 → Contactor A1; Contactor A2 → N.
6. Terminate the lighting MCB through the contactor. Lighting MCB load → Contactor L (in); Contactor T1 (out) → Lighting L; Lighting N → N bus; Lighting PE → PE bus.
7. Re-energise the MCB and verify the LOGO! powers up. Display shows 'LOGO!' and the time. Use the cursor keys to navigate to the inputs menu and confirm I1 toggles when the PIR triggers.

Expansion Module Configuration

LOGO! 8.x base modules support a backplane bus that carries digital I/O and analog I/O between the base and up to 8 expansion modules, plus up to 2 communication modules (CMK2000, CMR2020, etc.). The total address space is bounded by firmware, not by a hardware connector count.

Modules are daisy-chained to the right of the base; the bus connector on the left of the expansion module mates with the bus connector on the right of the previous module. There is no separate cable to buy — the bus is integrated in the module housings. No termination resistor is required.

Module Compatibility Table

Mixing voltage classes is permitted by the firmware; only the expansion module's own supply needs to be present and correctly referenced. A 230 V base and a 24 V DM8 can coexist as long as the 24 VDM8 has its own 24 VDC power supply — the bus carries only logic-level signals, not power. This allows irrigation valves (typically 24 VAC) and alarm sensors (typically 12/24 VDC) to be added later without disturbing the lighting wiring.

Maximum System Configuration

For the exterior lighting + irrigation + alarm project described in the original question, a representative maximum build is:

• 1 × LOGO! 230RCE base (8 DI / 4 DO)
• 1 × DM8 230R (4 DI / 4 DO) for additional lighting zones
• 1 × DM16 230R (8 DI / 8 DO) for grouped lighting and override pushbuttons
• 1 × DM8 24R (4 DI / 4 DO) for irrigation valve actuators on 24 VAC
• 1 × AM2 (2 AI) for a 4–20 mA light-level sensor for dusk/dawn switching

This uses 24 DI (limit), 20 DO (limit), 2 AI (limit), and 5 expansion modules (limit 8). The system will accept the configuration but LOGO! Soft Comfort will issue a warning if any resource is exceeded at compile time.

Programming the Lighting Logic (LOGO! Soft Comfort)

A minimal lighting program consists of three blocks:

1. Weekly timer (B001): enables scheduled operation between sunset and a fixed time, e.g. 18:00 to 23:00 Mon–Sun. Output of B001 drives an OR gate to Q1 (contactor = base brightness).
2. Edge-triggered one-shot on the PIR (B002): a positive edge from I1 starts an off-delay (B003) of, e.g., 120 s. Output of B003 drives Q2 (boost to 100 % via a second contactor or a 1–10 V signal).
3. Yearly timer / astronomical clock (optional, B004): disables the entire system between fixed dates (e.g. December holiday period).

Example block list in LOGO! Soft Comfort ladder notation (FBD is functionally identical):

B001  Weekly Timer     Cam1 = 18:00, Cam2 = 23:00, Mon..Sun   -> Q1 (dim)
B002  Edge detector    Input = I1 (PIR), edge rising         -> trigger B003
B003  Off-delay        Ta = 120 s                            -> Q2 (boost)
B004  Yearly timer     Off  = 23 Dec..02 Jan                  -> disable B001
B005  OR               B001 OR B002 (or manual override I2)  -> Q1

Verification and Commissioning

1. Apply power. Confirm LOGO! powers up and shows no '?' (unknown module) marker on the display.
2. Force Q1 from the menu: the contactor must pull in audibly; the lighting must illuminate. Listen for contactor chatter indicating under-voltage.
3. Trigger the PIR by walking through the detection zone. Confirm I1 indicator on the LOGO! display toggles for the duration of the PIR pulse.
4. Monitor Q2 (boost) for the configured 120 s after the PIR trailing edge.
5. Check the weekly timer by setting the on-time to one minute in the future and verifying the lighting comes on without the PIR.
6. Measure the contactor coil voltage under hold: should be ≥ 195 VAC at 230 VAC nominal. Below this, the contactor will buzz and contacts will pit.
7. Record all parameters in the LOGO! project comment and export the LSC file for archival.

Troubleshooting Matrix

Field-Notes Summary

For an exterior lighting project that starts with one zone and is later expanded to irrigation and alarms, plan the LOGO! build for the largest expected I/O count from day one. Buy a 230RCE rather than a 230RCo (the Ethernet model is field-upgradable and supports remote access via the LOGO! Access Tool). Always derate the on-board relay by routing the load through a contactor — the cost of a 25 A four-pole contactor is small compared with the labour of replacing a welded relay output. Use the integrated bus for expansion: there is no separate ribbon cable to specify or lose. If you need a 24 V sensor on a 230 V base, add a DM8 24R rather than re-architecting the whole station. Finally, document the earth topology in the as-built drawings so the inspector can see that the PE is correctly bonded at the panel and the load, not at the LOGO!.