Deep Sea 3110 Auto Start Module: Wiring Guide

Deep Sea 3110 Auto Start Module: Wiring Guide

Getting the wiring right on the first pass saves a significant amount of rework. The deep sea 3110 — formally the DSE3110 — is one of the most widely deployed entry-level auto start modules available for single gen-set standby applications. This guide covers terminal connections, AMF sequence logic, configuration parameters, and a side-by-side comparison with SmartGen HGM, so engineers and system integrators can approach the deep sea 3110 installation with a clear plan.

What Is the Deep Sea 3110?

The deep sea 3110 is a 12 V DC manual and auto start control module manufactured by Deep Sea Electronics Ltd, a UK-based controls specialist founded in 1975. The module handles AMF (Auto Mains Failure) and manual start functions for single gen-set and engine-only applications. Deep Sea's product hierarchy runs from the DSE3000 series up through DSE4000, DSE7000, and DSE8000 modules; the deep sea 3110 sits at the entry level of that range.

To be clear from the start: the deep sea 3110 is a control module, not an AVR. Voltage regulation is handled separately by an avr transformer assembly — whether a Leroy Somer AVR, a 3000 watts AVR unit, or a brand-specific regulator fitted to the alternator. The DSE3110 manages engine starting, stopping, and load transfer. This distinction prevents one of the most common wiring mistakes: assuming the deep sea 3110 needs to connect into the AVR circuit.

DSE3110 Terminal Overview

The deep sea 3110 uses a compact terminal block layout. Key connection groups are:

• DC Supply: Battery positive and negative (12 V DC). Connect battery negative first to avoid accidental cranking.
• Engine Outputs: FUEL output and CRANK output. The FUEL terminal energises the fuel solenoid relay during start and run; CRANK drives the starter motor relay. These two are sequenced by the module and must not share a common wire.
• MPU (Magnetic Pick-Up): Engine speed sensing input. The MPU fitted to the flywheel ring gear sends a frequency signal for run confirmation and overspeed detection. Correct MPU gap — typically 0.5–1.5 mm — is critical for reliable detection.
• Mains and Generator Sensing: Single-phase AC inputs for mains voltage and generator voltage monitoring. Mains sensing detects supply failure; generator sensing confirms output before load transfer.
• Load Transfer Output (W/L): Controls the ATS panel contactor or changeover switch.

If the application requires three-phase mains sensing or remote telemetry, the deep sea 3110 is not the correct fit — the DSE4520 or DSE7320 range addresses those requirements.

AMF Wiring: Step-by-Step Connection Sequence

Work through DSE3110 connections in this order to reduce the risk of an unintended crank during installation:

1. Disconnect battery and AC mains supply before starting.
2. Wire DC supply terminals: battery negative first, then positive through a rated fuse (see DSE3110 document 057-086 for fuse specification).
3. Wire FUEL output to the fuel solenoid relay coil. Confirm relay coil voltage matches module output.
4. Wire CRANK output to the starter motor relay coil. Verify inrush current rating.
5. Wire MPU terminals using screened cable; connect screen to earth at one end only to avoid ground loops.
6. Wire mains sensing input — single-phase line and neutral from the supply through a fuse.
7. Wire generator sensing input — single-phase line and neutral from generator output.
8. Wire W/L output to the generator ATS panel transfer contactor. Confirm control logic polarity before energising.
9. Reconnect battery and mains. Run initial commissioning in manual mode before enabling auto mode.

Transfer delays in the DSE3110 — start delay, transfer delay, and return delay — are all configurable in the module. Do not duplicate these delays in the generator ATS panel, or transfer times will exceed the intended values.

AMF Sequence Logic

With the deep sea 3110 in AUTO mode, the sequence runs as follows:

1. Mains voltage drops below the detection threshold.
2. Mains fail delay elapses (prevents nuisance starts on momentary dips).
3. FUEL output energises; CRANK activates for up to three configurable start attempts.
4. MPU signal confirms engine run; CRANK de-energises.
5. Generator voltage confirmed; load transfer delay elapses.
6. W/L output activates — ATS panel switches load from mains to generator.
7. Module monitors for return of mains supply.
8. Mains returns and stabilises through the return delay; ATS panel transfers load back.
9. Cool-down period elapses; FUEL de-energises, engine stops.

Deep Sea 3110 vs SmartGen HGM: Selection Comparison

The SmartGen HGM series — HGM6110 and HGM7220 — is the most common alternative engineers evaluate against the deep sea 3110 for single gen-set AMF applications:

If your priority is reliable single-phase AMF with broad parts availability in European and North American markets, the DSE3110 is typically the lower-risk choice. If front-panel LCD configuration without a PC is the priority, the SmartGen HGM is worth evaluating — subject to confirming English documentation in your region.

When to Upgrade from the Deep Sea 3110

The deep sea 3110 is the right tool for single-phase single gen-set AMF. If any of these requirements apply, a higher-spec module is needed:

• Three-phase mains and generator monitoring
• Remote telemetry or SCADA integration
• Parallel generator operation or load sharing
• Advanced protection relay functions

For three-phase AMF applications, the DSE4520 MKII Auto Mains Failure Control Module expands on the deep sea 3110 feature set with expanded mains monitoring and protection capabilities.

For full AMF with remote monitoring and a comprehensive protection suite, the POPULACE DSE7320 MKII AMF Generator Control Module is available from Populace inventory, with pre-sales technical support for specification confirmation.

For multi-generator parallel operation and synchronisation, the DSE8610 MKII Synchronising Load Sharing Auto Start Control Module handles load sharing beyond what the deep sea 3110 series covers.

Common Wiring Mistakes

• MPU gap too wide: The module fails to confirm engine run, and repeated crank attempts follow.
• Mains sensing on wrong phase: Gives a false mains-present reading on a three-phase supply.
• FUEL and CRANK outputs swapped: Causes starter engagement without fuel, or fuel open without cranking.
• No screened MPU cable: Electrical noise triggers false overspeed or speed loss signals.
• AVR transformer not wired correctly: If the avr transformer is not producing voltage, the generator sensing input on the deep sea 3110 will show no output — load transfer will not occur regardless of how the control module is wired.

Conclusion

The deep sea 3110 is a reliable, well-documented AMF controller for single gen-set standby applications. Correct wiring requires working through terminal connections in sequence, configuring transfer delays in the module rather than duplicating them in the generator ATS panel, and verifying MPU and sensing inputs before switching to AUTO mode. For applications that grow beyond the DSE3110's scope, the DSE4520 and DSE7320 range provide direct upgrade paths within the same controller family.