1. Introduction
The Simarine SPDU-52 power distribution unit is a very versatile module. Its purpose is to power other modules and shunts, which are used by the Caravan Panel. The SPDU-52 has 3 SICOM ports: two for additional power output input/outputs (SICOM 1, SICOM 2) and one for the Caravan Panel (SICOM PANEL). The SPDU-52 supports two batteries (main and starter). The voltage output is 8-22 VDC, and the temperature range is from -10 to +70°C (from +10 to +160°F). The SPDU-52 also has 4 channels (Solar, Charger, Main battery, Starter battery) that measure current with an accuracy of ±2%. Voltage measurement on any of these channels ranges from 0-35 VDC with an accuracy of ±0.5%. Resistance measurement on any of these channels ranges from 0-65kohm with an accuracy of ±3%. With additional modules, the SPDU-52 can connect up to 6 batteries, 24 shunts, 10 temperature sensors, 14 tank level sensors, and 2 inclinometer sensors.
2. Safety
Only qualified electricians with proper safety equipment should perform the installation of Simarine electronics. When working with batteries, wear protective clothing and eye protection.
CAUTION: Batteries contain acid, a corrosive, colorless liquid that can burn your eyes, skin, and clothing. Should the acid come in contact with eyes, skin, or clothing, wash it immediately under fresh water for at least 15 minutes and seek medical support.
CAUTION: Do NOT connect anything to a damaged battery. It could heat up, catch fire, or explode.
CAUTION: Lead-acid batteries can generate explosive gases during operation. Never smoke, allow flames, or sparks near the battery. Ensure sufficient ventilation around the battery.
CAUTION: When working with a battery, remove all personal metal items like watches, rings, necklaces, and bracelets. Metal items in contact with battery terminals might cause a short circuit with a very high electric current, potentially melting nearby objects and causing severe burns.
3. Overview
The SPDU-52 unit has several labeled connection points and components:
- A - 2 SiCom, 1 SiCOM Panel: Refers to the communication ports.
- B - Resistance inputs: Terminals for resistance-based sensors.
- C - Voltage inputs: Terminals for voltage-based sensors.
- D - 4 Stage Level 2: Inputs for a 2-stage level sensor.
- E - 4 Stage Level 1: Inputs for a 1-stage level sensor.
- F - Main and starter battery: Connection points for the vehicle's batteries.
- G - Manual main switch: A switch to turn the unit ON or OFF.
- H - Solar charger: Connection point for a solar charger.
- I - Charger: Connection point for a battery charger.
- J - Inputs and outputs: General terminals for various connections.
- K - Common ground: The main ground connection point.
4. Installation
4.1 Mounting
CAUTION: Install the power unit in a clean and dry place protected from accidental spilling of liquids. Remove the shunt cover by unscrewing two screws on top of the power unit cover. To install the power unit using supplied voltage cables, find a place no further than 3 m away from the battery/battery bank. You can fix the power unit with the supplied screws using four holes (two on each side) on the bottom of the casing.
4.2 Cables
CAUTION: Failure to observe the required cable cross-sections can damage the shunt, wiring, or cause a fire.
SiCOM data cable: For the SiCOM connection, use the supplied cable. For cable lengths less than 5m, there are no limitations. For cable lengths of 5m or more, a 2x2x0.25 mm² twisted pair cable is recommended.
4.3 SICOM Panels
The SPDU-52 features three SICOM ports:
- A - SICOM1 port: Used for an optional power input, such as an extra port to connect a SIMARINE module.
- B - SICOM2 port: Used for an optional power input.
- C - SICOM PANEL port: Used to connect the Caravan Panel.
5. Connecting
The Caravan Panel must be connected to the third port on the SPDU-52 (SICOM PANEL) to function correctly. If you have an Inclinometer module, it can be connected directly to the second port of the Caravan Panel or to SICOM port 1 or SICOM port 2 on the SPDU-52.
Resistance inputs can be used to connect temperature sensors, resistance tank sensors, 4-stage level tanks, or any resistance-based sensor. Auxiliary voltage inputs can be used to connect any sensor that outputs voltage.
5.1 Diagram
The diagram illustrates the SPDU-52 unit and its integration into a caravan's electrical system. The central component is the SPDU-52, with its various input and output terminals clearly marked. SICOM ports (SICOM 1, SICOM 2, SICOM PANEL) are shown, with the SICOM PANEL port connecting to the Caravan Panel. Inputs include Auxiliary voltage inputs, Resistance inputs for sensors like temperature and tank level, and 4 Stage Level 2 and 4 Stage Level 1 inputs, each with percentage marks (25%, 50%, 75%, 100%) and a base input. Power sources are connected: Starter Battery (+/-), Main Battery (+/-), Solar Panel (+/-), and Charger. Outputs are shown connected to various caravan loads via Relay outputs K1-K6 (labeled for Fridge, Water Pump, Heating, AC, Lights) and outputs F1-F12. Ground (GND) connections are shown for various components. A note indicates that a specific color represents devices sharing the same current. An Ampermeter symbol indicates current measurement capabilities. An Inclinometer module is depicted, showing its connection to the system. Tank symbols are shown, connected to the level sensors.
6. Technical Specifications
| Parameter | SPDU-52 |
|---|---|
| Operating Voltage Range | 8-22 VDC |
| Main Battery Voltage | 8-22 VDC |
| Starter Battery Voltage | 8-22 VDC |
| Temperature Range | -10 to +70°C (-10 to +160°F) |
| Power Consumption at 12V (Operating) | 15mA |
| Power Consumption at 12V (Power off) | 0.25mA |
| Current Measuring Channel 1 (Solar) | 0-16A |
| Current Measuring Channel 2 (Charger) | 0-40A |
| Current Measuring Channel 3 (Main Battery) | 0-50A |
| Current Measuring Channel 4 (Starter Battery) | 0-50A |
| Current Measuring Accuracy | ±2% |
| Current Measuring Resolution | ±0.1 A |
| Current Measuring Sample Rate | 100ms |
| Voltage Measuring Range (any channel) | 0-35 VDC |
| Voltage Measuring Accuracy | ±0.5% |
| Voltage Measuring Resolution | 10mV |
| Resistance Measuring Range (any channel) | 0-65kohm |
| Resistance Measuring Accuracy | ±3% |
| Resistance Measuring Resolution | 1ohm |
| Temperature Measuring (resistance inputs) | NTC 5K |
| Temperature Sensor Range | -15 to +80 °C (-10 to +160°F) |
| Temperature Sensor Resolution | 3% |
| Max. Continuous Current for Output Channels (K1) | 20A |
| Max. Continuous Current for Output Channels (K2) | 20A |
| Max. Continuous Current for Output Channels (K3) | 15A |
| Max. Continuous Current for Output Channels (K4) | 15A |
| Max. Continuous Current for Output Channels (K5) | 10A |
| Max. Continuous Current for Output Channels (K6) | 10A |
| All Channels Simultaneously | 50A |
| Contact Continuous Current Rating (Outputs F1-F12) | 20A |
| Contact Continuous Current Rating (Charger) | 40A |
| Contact Continuous Current Rating (Solar) | 16A |
| Dimensions (without connector) SPDU-52 | 200 x 160 x 42 mm (7.87 x 6.3 x 1.65in) |
| Dimensions (without connector) Caravan Panel | 157 x 82 x 25 mm (6.18 x 3.23 x 0.22in) |
| System Capabilities (with additional modules) Batteries | Up to 6 |
| System Capabilities (with additional modules) Shunts | 24 |
| System Capabilities (with additional modules) Temperature sensors | 10 |
| System Capabilities (with additional modules) Tank level sensors | 14 |
| System Capabilities (with additional modules) Inclinometer sensors | 2 |
| System Capabilities (with additional modules) Smartphone application | 1 |
| System Capabilities (with additional modules) Logger capacity | Up to 3 years |
7. Troubleshooting
If the Caravan Panel is showing an incorrect current value, check if the shunts are correctly installed. This means the consumer/generator's minus (or optionally plus) terminal is connected to the IN terminals on the shunts. If this is not the case, you can reinstall the shunts or simply switch the IN and OUT terminals via the shunt configuration on the Caravan Panel.
7.1 Shunt Sensors not visible
If the shunt sensor is not visible in the Caravan Panel menu, check the following:
- Is the Caravan Panel properly connected to the SICOM PANEL port (Third port on SPDU-52)? If you are using your own SiCOM cable, make sure it has the right square and is twisted.
- Is the Inclinometer module connected properly to SICOM port 1 or 2 on the SPDU-52 or directly to the Caravan Panel?
