Davey HS Series - User Manual

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Summary

HS Series Multistage Pump Assembly

HS Series Multistage Pump Disassembly

Trouble Shooting

Automatic Pressure System Operation Check

Instructions for verifying automatic pressure system functionality and settings.

This manual describes the HS Series Multistage Pumps, specifically models HS50-05, HS50-06, HS60-06, and HS60-08. These pumps are designed for various water transfer applications, likely including domestic, agricultural, and light industrial uses, given the focus on pressure systems and general water supply. The "multistage" designation indicates that the pump uses multiple impellers to achieve higher pressures than a single-stage pump, making them suitable for applications requiring significant head.

Function Description

The HS Series Multistage Pumps are designed to move water and build pressure within a system. As multistage pumps, they utilize a series of impellers and stage bodies to progressively increase the water pressure. Water enters the pump, is accelerated by the first impeller, and then directed to the next stage, where the process is repeated, building pressure with each stage. This design allows for efficient operation in scenarios where high pressure is required, such as boosting water supply to multiple outlets or over long distances. The pumps are equipped with a motor that drives the impellers, and the entire assembly is housed within a casing.

The manual also touches upon automatic pressure system operation, suggesting that these pumps can be integrated into systems that automatically switch on and off based on water demand and pressure settings. This is a common feature for domestic water supply systems, where the pump maintains a desired pressure range, activating when pressure drops (e.g., when a tap is opened) and deactivating when the desired pressure is reached (e.g., when all taps are closed).

Important Technical Specifications

While specific performance curves or detailed electrical specifications are not provided in the excerpt, the manual does offer crucial information regarding assembly and maintenance torque settings:

Casing screws: 7-9Nm
Check valve: 4-7Nm
Impeller nut: 10Nm

These torque settings are vital for ensuring the proper sealing and structural integrity of the pump, preventing leaks and ensuring efficient operation. The models listed (HS50-05, HS50-06, HS60-06, HS60-08) likely refer to variations in flow rate, head, or motor power, with the numbers potentially indicating the number of stages or specific performance characteristics.

The pump motor is fitted with an automatic reset thermal overload. This is a critical safety and protection feature. It automatically shuts off the motor if it overheats due to issues like low voltage, excessive ambient temperature (above 50°C) in the pump enclosure, or a seized pump. The "automatic reset" nature means the motor will attempt to restart once it cools down and the fault is cleared. However, the manual explicitly warns that constant tripping indicates a problem and that the pump should always be disconnected from the electrical supply before maintenance due to the automatic restart capability.

Usage Features

The HS Series pumps are designed for ease of assembly and maintenance, as detailed in the "HS Series Multistage Pump Assembly" and "HS Series Multistage Pump Disassembly" sections.

Modular Design: The pump components, such as impellers, stage bodies, and wear rings, are assembled in a sequential manner, suggesting a modular design that simplifies replacement of individual parts.
Mechanical Seal: The use of a mechanical seal with a ceramic wear face and carbon seal face is a standard feature for preventing water leakage along the motor shaft. Proper installation of this seal is emphasized for effective operation.
Impeller Drive: The impellers feature two flats that correspond to flats on the shaft, ensuring a secure drive and preventing slippage.
Priming Aid: The first stage body is designed with a "top" marking adjacent to the outlet port, which is crucial for correct assembly to aid in the priming of the pump. Proper priming is essential for any centrifugal pump to operate effectively.
Non-Return Valve Cartridge: The pump includes a non-return valve cartridge in the suction port, which helps prevent water from flowing back into the suction line when the pump is off, maintaining prime and system pressure.
Motor Mounting Flexibility: The Davey HS casing design allows the motor to be fitted at a 90-degree angle to the outlet port. This feature is particularly useful for wall-mounting the motor, offering flexibility in installation layouts and potentially saving space. In this configuration, the outlet port and first stage body should be uppermost.

Maintenance Features

The manual provides comprehensive instructions for both assembly and disassembly, highlighting key maintenance aspects:

Disassembly Procedure: Detailed steps are provided for disassembling the pump, including removing casing screws, prying off the backplate, removing the first stage body, and accessing the impeller nut. This systematic approach helps technicians identify and address issues efficiently.
Component Inspection: During disassembly, the manual instructs users to check various components for wear, rub marks, tears, flat spots, or signs of heat. This includes impellers, wear rings, stage bodies, mechanical seals (seal faces and rubber boot), and O-rings. Regular inspection helps in proactive maintenance and replacement of worn parts before they lead to major failures.
Lubrication: Light lubrication with an approved silicon grease is recommended for O-rings during assembly, ensuring proper sealing and ease of installation.
Tool Requirements: A list of specific tools is provided (5mm Allen Key, Pozi Drive Screw Driver, 17mm Ring Spanner Socket, Flat Blade Screw Driver), indicating that standard tools are sufficient for most maintenance tasks.
Troubleshooting Guide: A dedicated section addresses common problems such as "Pump not delivering water or not building up pressure," "Motor not running," and "Motor thermal overload tripping." This guide helps users diagnose issues based on symptoms, providing potential causes like improper priming, leaking foot valves, blocked impellers, power failure, or faulty motor windings.
Automatic System Troubleshooting: For pumps integrated into automatic pressure systems, additional troubleshooting steps are provided for scenarios like "Pump switching on and off frequently when no taps are turned on" and "Pump not switching off or taking too long to switch off." These issues often relate to leaks in the system, faulty pressure tanks, or worn pump components.
Safety Warnings: The manual places a strong emphasis on safety, particularly regarding electrical work (to be performed by qualified personnel only), disconnecting power before any work, releasing pump pressure, and avoiding petroleum-based fluids on plastic or seal components. It also warns about the automatic reset thermal overload and the potential for hot pressurized water.

In summary, the HS Series Multistage Pumps are robust, modular units designed for efficient water pressure boosting. The manual emphasizes proper assembly, regular inspection of components for wear, and adherence to safety protocols, all supported by clear instructions and troubleshooting guidance. The flexibility in motor mounting further enhances their adaptability to various installation environments.