Crown Forklift RT3010 Electrical Components

Electrical Components

Transmitter (MMI,MMA,PT) 

The transmitter is manually activated via a cam switch. It comprises the switches (MMI and MMA) which indicate forward and reverse travel and a potentiometer (PT) which governs the travel speed.

Fast / Slow Switch (HES) 

The Fast / Slow switch is activated via a toggle switch (rabbit / tortoise & rabbit symbols) on the instrument panel. High and low speeds can be selected via the switch signal to the traction controller.

Safety Pedal (PCT) 

The safety pedal (PCT) activates the brakes via the control system. The brake is released and at the same time power supply is released to the drive motor (M1) via the input (A5) of the traction controller. When the safety pedal is released the input (A5) of the traction controller is de-energised. The traction controller cuts out the power supply to the drive motor and the spring-loaded brake. The brake magnet is disengaged and the truck brakes. Trucks with Electrical Power Steering: The safety pedal (PCT) applies the brake via the EPSDC steering control system. The brake is released and at the same time power supply is released to the drive motor (M1) via the input (A5) of the traction controller. When the safety pedal is released the input (A5) of the traction controller is de-energised. The traction controller cuts out the power supply to the drive motor and the spring-loaded brake. The brake magnet is disengaged and the truck brakes. 

Lift / Lower Switch (PCS, PCD) 

The lift (PCS) and lower (PCD) switches are both manually activated via a press button in the instrument panel. The Lift (PCS) switch activates the auxiliary relay (RLS), the lift limit switch (MFF) as well as the pump contactor (K3) and the “Lift” solenoid via the control system. The pump motor (M2) starts up.The Lower switch (PCD) activates the “Lower” solenoid via the auxiliary relay (RLD). The pump contactor (K4) simultaneously opens via the control system while the pump motor (M2) is inactive.

Lift Limit Switch (MFF)

The limit switch (MFF) interrupts the auxiliary relay (RLS) power circuit when the preset maximum height is reached. Consequently the control system cuts out the pump contactor and the pump motor is inactive.

Pressure Switch (PS) 

The pressure switch is applied, when the load raised exceeds 500 kg, due to the rise in pressure in the hydraulic system. The second brake level is then made available.

Horn Switch (PCX) 

The buzzer sounds when this switch is pressed. 

Horn (CX)

The horn is located in the truck’s engine compartment. 

Key Switch (QC) 

The key switch activates the traction controller (input A2). 

Seat Height Adjustment Switch (PSDS) 

The commutator changes the polarity of the power supply (positive from A5 output of traction contoller) of the variable displacement motor (M5) depending on its position. A spindle drive adjusts the seat backrest accordingly. 

Steering Angle-Dependent Speed Reduction Microswitch

This microswitch senses an angle on the traction motor fitted with rotation bearings. If the steering angle is greater than 10 degrees, the ramp opens the switch. Input C3 of the traction controller falls to 0 volts and the control system reduces the max. travel speed. This is a safety function to avoid excessive curve speeds.

Seat Height Adjustment Limit Switch (MF)

This microswitch senses a cam switch on the spindle of the seat variable displacement motor.

Fans (VNT) 

Both fans supply air from the motor compartment to cool the drive components. Both receive positive voltage supply from output A5 of the traction controller.

Brake (FE) 

The two-stage electromagnetic brake is spring-loaded and applies when the truck is de-energised (parking brake). In travel mode the brake only applies when the safety pedal (PCT) opens or the emergency stop switch is pressed.

Emergency Disconnect Switch (PE) 

Pressing the Emergency Disconnect Switch interrupts the voltage supply to input (A2) of the traction controller. This activates the contactors (K3) and (K4), the traction motor and the lift motor remain inactive, the springloaded brake (FE) is de-energised and brakes the truck

Fuses (F1, F2, FA) 

The entire drive current circuit is protected by fuse F1 while the lift current circuit is controlled by fuse F2. The fine fuse (FA) protects the control circuit.

Traction Motor (M1) 

The traction motor is a separately excited DC motor and is governed by the traction controlled.

Pump Motor (M2) 

This is a DC motor. The contactor (K3) applies positive power supply for the pump motor (M2) when a lift request is received.