Adjusting the Automatic Throttle, Adjustment

ADJUSTING THE AUTOMATIC THROTTLE

GENERAL DESCRIPTION

The AUTOMATIC THROTTLE function is triggered by an adjustable pressure switch located on the hydraulic manifold.

Throttle Control

Pressure Switch

Pressure

Relief Valve

When the ﬂow selector is set to (for example) 40 liters (10 gal), that amount of oil will circulate through the hoses and through the tool and back to the tank.

The circulation of the oil through the hoses creates a small pressure (known as “back pressure”) at the pressure switch.

The back pressure in the system can vary for many reasons such as;

-Cold hydraulic oil

-The length of the hoses – a longer hose creates more back pressure.

-The valve in the hydraulic tool can have a high restriction.

In some applications the hydraulic system restriction may be too low. This will cause the engine to remain at idle speed even after the tool is engaged and full power is required.

When a trigger is activated at the tool, the oil pressure quickly rises to in excess 50 bar (700 psi). This normally triggers the AUTOMATIC THROTTLE control to increase the throttle to “FULL”. It is desirable that the engine engages to full throttle immediately when the tool is activated.

ADJUSTMENT

On the PP 418 the threshold pressure at which the

throttle reacts can be adjusted to reach a desired function for a speciﬁc tool and condition.

Step 1

Hook up the hoses and tool to be used.

Step 2

Turn the AUTOMATIC THROTTLE switch to the ON position. Start the engine and let it idle for 1 minute. The engine will now idle at 1900 RPM.

Step 3

Turn the FLOW SELECTOR to the proper setting for the tool. Note: If the oil is cold the back pressure in the system can trigger the full throttle function.

Step 4

Let the hydraulic oil warm up for one or two minutes. It is now OK to start the work. The hydraulic oil will reach a stabilized operational temperature in approximately 5 to 10 minutes.

Step 5

If the machine has been operated for 10 minutes and the AUTOMATIC THROTTLE function is not working correctly the pressure threshold value between the idle and full throttle function can be adjusted.

NOTICE:

The Throttle Control Pressure Switch setting has NO impact on the relief valve setting (= maximum system pressure). It is strictly sensing the system pressure to signal the controller to operate the engine at Idle or Full Throttle.

DO NOT adjust the pressure relief valve.

Use an 8 mm or 5/16” hex key to adjust the throttle threshold pressure

Scenario 1.

With the Automatic throttle switch in the ON position, the engine will stay at FULL THROTTLE even when the hydraulic oil is hot.

Adjustment Turn the Adjustment Screw - Clockwise in 1/8 turn increments until proper function is achieved.

Scenario 2.

The engine will remain at IDLE SPEED when the tool is engaged. It might work OK when the oil is cold.

Adjustment Turn the Adjustment Screw - Counter Clockwise in 1/8 turn increments until proper function is achieved.

PP 418 specifications

The Husqvarna PP 418 is a versatile and powerful pole saw designed specifically to tackle various pruning and cutting tasks with ease and efficiency. Tailored for both homeowners and professionals alike, the PP 418 combines an array of innovative technologies and features that enhance its usability and performance.

One of the standout characteristics of the Husqvarna PP 418 is its lightweight design, which allows users to maneuver it effortlessly during extended periods of use. This feature is advantageous for homeowners with larger gardens or for professionals who often find themselves working in different locations. The telescopic shaft can be extended, increasing its reach and enabling users to access high branches without the need for a ladder.

Powering the PP 418 is a robust gas engine that provides a perfect balance of power and efficiency. This ensures that users can efficiently cut through thick branches and limbs without experiencing the fatigue associated with weaker saws. The engine is engineered to offer outstanding torque, allowing for smooth operation even under heavy load conditions.

Safety is another priority in the design of the Husqvarna PP 418. It features a protective hood that shields the operator from falling debris while working. Additionally, the ergonomic handle is designed to provide a secure grip, reducing the risk of accidents during operation. The weight distribution of the tool has been carefully considered to minimize strain on the user's arms and back.

Husqvarna's unique LowVib® technology is incorporated into the PP 418, which significantly reduces vibrations experienced during operation. This added feature not only enhances comfort but also helps to prevent long-term health issues associated with prolonged exposure to vibrations.

Another notable feature of this pole saw is the easy-to-use chain tensioning system, which allows users to adjust the chain tension quickly without the need for additional tools. This is particularly beneficial for maximizing efficiency and maintaining optimal performance throughout the workday.

Moreover, the Husqvarna PP 418 is equipped with a quality cutting bar and chain that ensures clean cuts every time. The durable materials used in its construction promote longevity, making it a worthwhile investment for both casual users and professionals who require reliability in their equipment.

Combining innovative features, outstanding power, and user-friendly design, the Husqvarna PP 418 stands out as an excellent choice for anyone looking to maintain their trees and shrubs efficiently and safely.