CONNECTION 7W4682 - Caterpillar

Mounting
Mount the tachometer inside the control panel or mount the tachometer to a suitable flat surface so that the display is at a convenient height. A template for drilling is provided.Note: Do not mount the tachometer so that the digital LCD display faces the direct sunlight. The temperature range of the display is −40 °C (−40 °F) to 80 °C (175 °F).Mount the magnetic pickup securely to a rigid bracket or a surface. Refer to Testing and Adjusting, "Speed Sensor - Adjust".Wiring
General
Take care not to damage the insulation and take precautions against damage from the following reasons: vibration, abrasion and liquids in the conduits. Never run the following applications in the same conduit as the ignition wiring or other wiring with high energy such as AC power: low voltage power, current loop and the wires from the tachometer for the output. Keep the wires at least 305 mm (12 inch) away from all high voltage wiring.Power Wiring
Connect the wires for the input of the power to terminal "5 (-)" and terminal "6 (+)". The power requirement is 12 VDC to 36 VDC. The minus terminal "(-)" is connected to the panel ground which should be the same ground for the engine.Magnetic Pickup
Connect the two wires that come from the magnetic pickup to the back of the gauge. Connect the wires to terminal "4" and to terminal "5". Use a cable assembly in order to make this connection.Output Switch Wiring
A fault condition will cause the output switches that are configured for the "normally open" position to turn ON. A fault condition will cause the output switches that are configured for the "normally closed" position to turn OFF. When the switches are in the unpowered condition, the switches are in the open state. These solid state switches with "Form A" contacts are also isolated from the power supply. The switches are rated at 200 V and 140 mA, and the switches use a unique internal overload current protection circuit. If an overload occurs, the internal circuitry limits the current to safe levels. When the overload is removed, the relay resumes the normal ON characteristics. Output Current Loop Wiring
The 150-7700 Tachometer has a current loop with a range of 4 mA to 20 mA. The output of the current loop is accessible through terminal "7" and terminal "8". This output is internally limited to 20 mA. The output is protected against open circuits and closed circuits. A 250 ohm resistor can be used over the entire range of the supplied voltage from 12 VDC to 36 VDC. The maximum load resistance that can be tolerated in the loop is determined by the supply voltage. When the maximum rated resistor of 500 ohms is used with a desired output from the loop of 20 mA, the supply voltage must be between 15 VDC and 36 VDC. At a supply voltage of 12 VDC, the maximum resistor for the load is 350 ohms for a 20 mA output from the current loop.