Iveco NEF N40-ENT-M25 Installation Directive Manual
We strongly recommend that you carefully read the indications contained in this document: compliance with them protects the engine against irregular operation and assures its reliability, safe guarding sea-going and maintenance personnel against accident hazards.

The indications contained in this directive pertain to the N40 ENT M25, N60 ENT M37 and N60 ENT M40 engines and complement the IVECO MOTORS publication “Guide to the Installation of Marine Engines” the reader should refer to, for anything that is not explained herein. For more complete information about the engine, please refer to the appropriate technical brochure. Use of fuels and oils with different characteristics from those set out in the operation and maintenance manual may compromise the regular operation of the engine, limiting its performance, reliability and working life.
Exclusive use of IVECO Original Parts is a necessary condition to maintain the engine in its original integrity. Tampering, making modifications and using non original parts can jeopardize the safety of boat engineers and users.
To obtain spare parts, you must indicate:
- Commercial code, serial number and indications shownon the engine tag;
- Part number of the spare as per spare part catalog.
The information provided below refer to engine characteristics that are current as of the publication date. IVECO MOTORS reserves the right to make modifications at any time and without advance notice, to meet technical or commercial requirements or to comply with local legal and regulatory requirements.
ELECTRICAL EQUIPMENT
The electrical equipment of the engine comprises a series of components provided separately from the engine to enable an easy and diversified installation, according to the Yard’s design choices. The need to make accessible, at sea or underway, the controls to the electrical components and to the connector for diagnostics contained in the relay box may be met through different installation arrangements.
Along with the coupling of all connectors provided in the wire harnesses, completing the installation also requires the connecting wire harness (12) for the sensor for the presence of water in the fuel (13), to complete the power line and to connect the accumulator to the engine wire harness. To obtain the engine stop if stressed function simply connect the ECF and ECM connectors to each other (these are present on the wiring of the new model).
Power supply line
The connection of the +B terminal of the alternator to the positive +30 terminal of the electric starter motor must be achieved with a conductor having a cross section of at least 10 mm2. The connection of the positive +30 terminal of the electric starter motor to the positive pole of the battery, achieved with a conductor having a cross section of at least 70 mm2, allows to obtain, as shown in the figure, the simultaneous connection of the alternator to the battery. The connection between the engine ground and the negative pole of the battery must be achieved according to the guidelines provided in the Engine electrical ground paragraph.
Supplementary services battery
To assure that the engine can be started with a sufficient quantity of energy, it is advisable to provide for the installation of a supplementary battery, dedicated to supplying power to the on-board electrical services. The power line to recharge it may be constructed according to the indications provided in Chapter 24.
If one engine is installed
The battery used for services may be recharged interposing on the power supply line a relay actuated by the recharge signal of the alternator’s electronic regulator (D+).
If two engines are installed
The presence of two generators allows to keep the recharging functions separated: the generator (G1) recharges the battery (AC1) dedicated to starting both engines and powering both electrical/electronic control circuits, whilst the generator (G2) recharges the battery (AC2) used to power the services. In two-engine applications, it is essential to connect the engine grounds to a common potential; the solution proposed in Chapter 24 fully complies with this need, assuring the full functionality and independence of the two circuits.
Engine electrical ground
The connection of the engine electrical ground is achieved by connecting with a cable of at least 70 mm2 cross section to the negative pole of the battery to the tightening point of the electric starter motor as shown in Figure 14.
To anchor the grounding terminal to the engine, proceed as
follows:Completely remove the conducting paint from both parts constituting the connection, using mechanical means or suitable chemical product; if the anchoring operation is to take place on superficially treated parts, completely remove the anaphoretic paint with mechanical means, obtaining a smooth support surface. Apply a uniform layer of BH44D paint (IVECO standard 18-1705) with a brush or spray gun. Join the parts constituting the grounding note within 5 minutes from the time the paint was applied.
Battery recharging
This is accomplished through the power supply line of the electric starter motor and connection to the +B of the alternator. The electronic regulator of the alternator that equips the engine allows an effective control over the battery recharging operation. If, due to installation requirements, the batteries need to be positioned at a distance from the engine, we recommend increasing the cross section of the power line conductors and verifying recharging effectiveness by measuring voltage across the battery poles.
Relay box
This shall be installed and anchored in such a way as to dampen the vibrations and stresses occurring when underway, and they shall be accessible during servicing operations and when underway. The electrical commands positioned on the panel allow to control engine starting and stopping (2) directly from the engine room, while excluding any possibility that anyone may involuntarily start the engine from the bridge (1), during servicing operations. Among the controls present on the panel are also the push-button (3) and the “blink code” light indicator (4), useful to obtain, also while underway, indications that will lead to identify failures or improper engine operating conditions (see Chapter 20).
On the relay box is located the multipolar connector, protected by a screw-on lid (5), for connection with the computerized diagnostic tools prescribed by IVECO MOTORS (see Chapter 20).
Inside the box, anchored to a printed circuit board, are present the power management relays of some components and the elements that protect the electrical lines against short circuits or excessive current absorption. These components perform a similar function to that of fuses, almost totally avoiding the need to restore the electrical continuity of circuits subjected to an anomaly condition. These components are able to limit and eliminate short circuit currents without melting, restoring their own and the circuit’s electrical continuity, once the cause of the anomaly is removed.
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