Systems Operation

Usage:

Introduction

NOTE: For Specifications with illustrations, make reference to Specifications For 3208 Generator Set Engine Attachments, Form No. SENR2533. If the Specifications in Form SENR2533 are not the same as in the Systems Operation and Testing And Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.

Electrical System

Contactor Switch For Water Temperature

The contactor switch for water temperature is installed in the front cover for the engine. No adjustment to the temperature range of the contactor can be made. The element feels the temperature of the coolant and then operates the micro switch in the contactor when the coolant temperature is too high. The element must be in contact with the coolant to operate correctly. If the cause for the engine being too hot is because of low coolant level or no coolant, the contactor switch will not operate.

Water Temperature Contactor Switch

The contactor switch is connected to the fuel shutoff solenoid to stop the engine. The switch can also be connected to an alarm system. When the temperature of the coolant lowers to the operating range, the contactor switch opens automatically.

Pressure Switch

These type pressure switches are used for several purposes and are available with different specifications. They are used in the oil system and in the fuel system. One use of the switch is to open the circuit between the battery and the fuel shutoff solenoid after the oil pressure is below the pressure specifications of the switch. It also closes when the engine starts.

Another use of the switch is to close and activate the battery charging circuit when the pressure is above the pressure specification of the switch. It also disconnects the circuit when the engine is stopped.

Some switches of this type have three terminal connections. They are used to do two operations with one switch. They open one circuit and close another with a single switch.

Pressure Switch

Electrical Gauges And Sending Units

The electrical gauges and sending units are to operate in electrical balance. Because of this, the voltage and resistance ratings are important to get the correct indications on the gauges. See Attachment Specifications to determine which gauges and sending units can be used with each other.

Sending Unit And Gauge For Water Temperature

The position of the pointer is changed by the amount of electrical current that flows through the gauge. The water temperature is felt by bulb (3) of the sending unit. A change in water temperature causes a change of resistance in the sending unit. A change in resistance in the sending unit changes the current flow through the gauge and changes the position of the pointer.

Sending Unit For Water Temperature
(1) Connection. (2) Bushing. (3) Bulb.

Sending Unit And Gauge For Oil Pressure

The position of the pointer is changed by the amount of electrical current that flows through the gauge. The oil pressure is felt by the sending unit for the oil pressure gauge. A change in oil pressure causes a change of resistance in the sending unit. A change in resistance in the sending unit changes the current flow through the gauge and changes the position of the pointer.

Oil Pressure Sending Unit
(1) Connection. (2) Fitting.

Engine Protection Panel

The engine protection panel has a magnetic control switch (5) in the panel. Pushing in and holding the reset button (4), while cranking the engine, permits the engine to start. When the oil pressure is above 105 kPa (15 psi), the engine will continue to run after button (4) is released.

Engine Protection Panel
(1) Oil pressure gauge. (2) Ammeter. (3) Water temperature gauge. (4) Reset button. (5) Magnetic control switch. (6) Fuse.

Water Temperature Contactor Switch

Pressure Switch

The normally open contactor switch for water temperature closes when the temperature of the coolant gets higher than the setting of the switch. The oil pressure switch closes when the pressure of the oil gets lower than the setting of the switch. If either the contactor switch for water temperature or the oil pressure switch is activated, they will trip (activate) the magnetic control switch (5). This will open the circuit between the fuel shutoff solenoid and the battery. With no fuel coming to the engine, the engine will stop. A 14 ampere fuse (6) gives protection to switch (5) if there is too much of a load put on it.

Wiring Diagram (3208 Generator-Set Engine)

Energized To Shutoff (ETS) System (with protection system)

Energized To Run (ETR) System (with protection)

Energized To Shutoff (ETS) System (no protection system)

Energized To Run (ETR) System (no protection system)

Gauges With Auto-Start-Stop System

Abbreviations And Notes

Notes

NOTE A: Optional ground to engine may be used with grounded systems only.

NOTE B: These leads terminate at the starting motor and must be omitted when there is no starting motor.

NOTE C: If 2301 Governor is used, only one magnetic pick-up is required. Use magnetic pick-up from over speed group. Wire from magnetic pick-up to speed switch, then wire from speed switch to the 2301 governor. The speed switch may be installed physically near the 2301 if desired.

NOTE D: Electronic dual speed switch and electronic time delay relay can be wired to battery power continuously since the system will draw less than 40 ma current when the engine is not running.

NOTE E: If required, customer is to supply (RNS) remote normal shut down switch. Requires a single pole N.O. switch with a minimum contact rating of 5 amps inductive at the charging system voltage. Can be a latching switch if customer prefers. Shuts off engine fuel when activated.

Diagram-Wiring (electric shutoff) Flyball Overspeed Only Shutoff