If the platform elevates, but fails to hold a load

valve has been included for the protection of all of the workers who use the unit.

3.If the motor is not running, check the electrical plug, the circuit breaker or fuse, and the wiring to the motor.

4.The hydraulic oil level may be low. In order to check the level, lower the unit completely and unplug the power cord. Remove the rear cover on the unit. When the platform is lowered as far as possible, the oil should be about 1/2’’ to 3/4’’ inch below the top of the tank. Remove the red plastic plug on top of the tank. Use a dipstick to check the oil level.

5.The motor voltage may be too low. Check the voltage at the starter when the motor is under load. The supply voltage should be within ±10% of the rating.

6.The tank vent may be plugged. Before operating the unit, you must remove the solid plug from the top of the tank and insert the red plastic vented plug. The vent line must be clear.

7.The suction filter may be clogged. Clean the suction filter as described in the section on “Periodic Maintenance.”

8.A vacuum leak may be allowing air into the suction line, causing cavitation (loss of suction) in the pump. Check all fittings in the suction line, and tighten or replace them if necessary.

CAUTION!

If cavitation is allowed to continue, the pump may be damaged, and may have to be replaced.

9.For the platform to raise, the down valve must be de-energized and closed completely. Check for a problem with the wiring to the down valve. Check the solenoid in the valve with a voltmeter. The valve must be clean and free to operate. To check this, remove the solenoid and then the valve. Look

for dirt or metal chips which could block the valve action. Clean the valve plunger with kerosene, then blow it clean with compressed air. The expansion nut which holds the solenoid should be finger tight only).

10.If the pump has been changed, the coupling may not have been installed between the motor and pump. See the pump assembly in Fig. 8.

If the platform elevates, but fails to hold a load:

1.The check valve may be leaking. Dirt on the valve seat can prevent the valve from closing fully. The check valve is mounted in the base of the pump housing, as shown in Fig. 8. Remove the check valve cap and inspect the valve for dirt or metal chips which may be preventing it from closing. You may be able to restore the seal by lightly rapping the ball into the seat using a 1/4" diameter rod and a small hammer.

2.The down valve may be energized. While the unit is holding a load, the down valve should be de-energized and fully closed. Check the solenoid in the valve with a voltmeter. The valve must be clean and free to operate. To check this, remove the solenoid and then the valve. Look for dirt or metal chips which could block the valve action. Clean the valve plunger with kerosene, then blow it clean with compressed air. The expansion nut which holds the solenoid should be finger tight only!

3.The cylinder may be leaking. Look for oil on the cylinder rod and in the vent line. (This may also occur if the oil tank has been over- filled.) If you find much oil in either place, and the tank is not over-filled, the cylinder must be repacked. See the section in this manual on “Repacking the Cylinder.”

If the platform fails to lower:

1.The sensor and reflector for the photo eye toe guard are mounted at the front of the unit, near the floor level. There may be something blocking the beam of the photo

14PRESTO P4 LEVEL LOADER OWNER’S MANUAL

P4 specifications

Presto P4 is a powerful computing platform designed to meet the demands of modern data processing and analytics. It serves as a cornerstone for businesses looking to handle large volumes of data efficiently, integrating cutting-edge technologies that enhance usability and performance.

One of the main features of Presto P4 is its high-throughput data processing capability. It utilizes a distributed architecture that allows it to process queries in parallel across many nodes. This means that even complex queries that involve large datasets can be completed in a matter of seconds, significantly improving response times for data analytics tasks.

In terms of scalability, Presto P4 is designed to scale out seamlessly. Businesses can begin with a modest setup and expand their system as their data needs grow. This flexibility ensures that organizations do not need to invest heavily in infrastructure upfront, allowing them to pay for only what they use.

Presto P4 incorporates advanced SQL support, allowing users to write standard SQL queries to interact with their data. This feature makes it accessible for data analysts and business intelligence professionals who may not be familiar with programming languages typically used in big data applications. The ability to query data from various sources—including relational databases, non-relational databases, and data lakes—further increases its utility.

Security is a crucial characteristic of Presto P4. It offers fine-grained access controls, ensuring that sensitive data is only accessible to authorized users. This ability to manage access is essential for organizations that handle confidential information and must comply with data privacy regulations.

Integrating Presto P4 into an existing ecosystem is straightforward. It supports a range of data connectors and can easily interface with popular big data frameworks such as Hadoop and Spark. Additionally, Presto P4 can work well with various data storage solutions, including cloud-based services, which enhances its versatility in diverse IT environments.

Another notable characteristic is its performance optimization features. The platform uses advanced query optimization techniques—such as predicate pushdown and dynamic filtering—to minimize the amount of data processed and improve overall efficiency.

In summary, Presto P4 stands out for its capabilities in data processing, scalability, SQL support, security, and integration. It is an essential tool for organizations that require fast, reliable, and secure access to their data, empowering them to derive actionable insights and drive business growth.