Selden Power Supply and SEL-Bus System — Installation Manual

The System

• Runs from a 10–30V boat supply and delivers up to 1000W. The Power Supply Unit (PSU) raises the voltage to 40–48V, just below the 50V high-voltage limit.
• PSU, Motor Control Units (MCU) and control buttons talk over a CAN bus called SEL-Bus: it carries diagnostics (flashing LED fault codes) and puts the system to sleep when idle.
• Sleep mode still draws a little current: switch off the main switch when you leave the boat.
• SEL-Bus is standalone: never connect it to another CAN bus such as NMEA 2000.
• One PSU per SEL-Bus system; each drive unit (E40i winch, SMF furling mast, Furlex Electric, CXe) has its own MCU. Parts come in PSU Start packs and Drive unit Control Packs (order guide 597-283-E).
• Each PSU should be connected to an emergency stop (pack = red illuminated button, protective guard and relay; see the Emergency Stop manual 597-219).

Component Data

• SEL-Bus cables (backbone and drop): 0,3m / 1m / 2m / 5m / 10m. Main switch/fuse 100A / 60A. PSU–MCU power cables yellow and dark blue, 6mm2 / 10mm2.
• SEL-Bus converter: turns push-button signals into SEL-Bus; supplied with 4x1,5m (red/green) push button cables.
• Not supplied by Selden: the 12V or 24V battery and the battery–PSU power cables.

PSU & MCU Wiring

Example from the manual: MCU A at 2x8 m = 16 m → 6 mm2; MCU B and C at 2x5m + 2x6 m = 22 m → 10 mm2. Extra MCUs connect in parallel, to the PSU or via another MCU.

1. Undo the 5 Torx T20 screws and lift the PSU lid.
2. Battery positive to +BAT, battery negative to -BAT (boat-standard colours).
3. Dark blue cable from PSU +VBUS to MCU +VBUS; yellow cable from PSU -VBUS to MCU -VBUS.
4. Open each MCU lid (T20), connect +VBUS / -VBUS, then the motor connection cables to L3, L2, L1 – positions vary by motor unit, follow its own manual.

Push Buttons & SEL-Bus Converter

1. Place the SEL-Bus converter near the buttons, protected from weather, LED visible.
2. Cut the green and red cables to length and fit the press connectors from the push button kit.
3. Connect green and red cables to their buttons per the push button sheet; optional backlighting preferably on the nav-lights switch.
4. Install the buttons where they cannot be pressed by accident when standing or sitting.

Illuminated push button (IP 67, Ø35mm, 540-457/540-459/540-460): control cables on positions 3 and 4 (normally open); backlight on a and b (12-24V, nav-lights circuit); positions 1 and 2 (normally closed) – do not use. Plug-in terminals 2,8x0,5. Panels: 540-462-01 (2x, 100x56x3mm), 540-461-01 (1x, 56x56x3mm), raised panel 540-482 (96x53x9mm); screws 2xMLC6S M5.

Junction box 532-487-01: turn the locks ¼ turn to open; knock out two perforated areas; fit the junction bridge with the blue locks at "0", then turn to "1"; mount with stainless screws (cover heads with grommets); fit the three-hole grommets, route and connect the cables (petroleum jelly on the ends); refit the lid strap and lock the lid.

Building the SEL-Bus Network

• Backbone runs along the boat and must start and end with the male and female 120-ohm end terminals.
• T-connectors (1 male, 2 female) join each unit's drop cable (max. 5 m) to the backbone.
• Total network length (backbone + drop cables) must not exceed 70m. Cables and T-connectors can be joined directly (2x 5m = 1x 10m).
• Keep the battery switch off until all SEL-Bus cables are in.

1. Male terminal to the first T-connector.
2. Drop cable from the first unit to the T-connector.
3. First backbone cable to the T-connector.
4. New T-connector at the end of that cable; repeat for each unit (PSU, MCU, buttons).
5. Finish with the female terminal.

Fuses & Fault Codes

• PSU fuses: 3A/5A for the SEL-Bus network (blown = communication failure); 30A power input (blown = green LED on PSU, other units dead).
• MCU fuse: 30A power input (blown = that MCU dead, others work). Replace with standard blade fuses of the correct rating.
• Warning codes flash white (count the flashes); error codes alternate colours. Codes can take up to a minute to appear after start-up and are not memorised: write them down before switching off.

PSU

MCU

SEL-Bus converter (red LED)

• The LED lights for 5 min after switch-on and after each button press when the converter is working and on the network.
• LED on, buttons dead: buttons not configured; or bad converter–MCU link (check MCU codes); or bad button–converter link (wait for the LED to go out, press a button: if it stays out, check cables or change the buttons).
• Flashing 2, 4 or 5 times: converter software/hardware error – replace it. 3 times: button error – check and clean connectors, replace buttons.
• LED off: no power from the network (inspect the network) or bad converter.
• Network faults: switch the system off and on once, read the codes on every unit (PSU, MCUs, converters) and compare them with the fault-location examples in the PDF.

Questions & Answers (597-518-E)

• Why 42V? Thinner power cables, lower battery current, smaller motors for their power; 42V rather than 48V because peaks over 50V count as high voltage in many countries. A 48V boat still needs the PSU on 12V or 24V.
• Consumption examples: hoisting a 12m mainsail with an E40i takes 40 sec at 35A average from 12V = 0,38Ah. Unfurling the main (SMF) on a 40' boat takes 30 sec at 25A = 0,2 Ah; furling = 0,08 Ah. Each MCU and the PSU draw 0,1 A asleep.
• Emergency operation: Furlex Electric has an emergency line driver with endless line as standard; SMF uses a winch handle in the original line driver; E40i: take the line to a regular winch.
• E40i: max working load 1100 kg static; electric cut-off during operation 600 kg.
• Motor cables: 5 meters, the maximum per the CE marking – do not lengthen.
• Motors and gearboxes are sealed and maintenance-free. All units must be on the SEL-Bus for any of them to run. A hum before and after running is the MCU checking motor resistance; the flash at switch-on is the LED, not a spark.