Overview; Product Description; Operation - ITT Lowara GMD Serie Manual De Instrucciones Para La Instalación Y El Uso

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1. Overview

The Lowara pressure booster sets, GMD, GMY, GSD, GSY series, are designed to transfer and boost
clean water pressure in water systems for homes, offices, communities and industry.
Operating limits
Fluid temperature:
Ambient temperature:
Operating pressure:
Minimum inlet pressure:
Maximum inlet pressure:
Starts per hour:
Limitations to fluid temperature and pressure may be imposed by the membrane
WARNING
tank. Observe the operating limits!

2. Product Description

The pressure booster set consists of identical electric pumps connected in parallel and mounted on a
common stand, suction and delivery manifolds, on-off valves, check valves, pressure gauge, pressure
switches and a Single-phase or Three-phase control panel.
The system must be equipped with a membrane tank. The delivery manifold is fitted with two couplings
designed for installation of 24-litre tanks with on-off valve. Along with the tanks, provide a suitable ma-
nifold support. Additional floor-standing tanks may be installed and connected to the manifold.
Depending on the model, a pilot pump or an air compressor control connector may be fitted.

3. Operation

The pumps are controlled by the electric panel according to system requirements.
The membrane tank provides for initial water demand.
When the pressure drops to the initial start value, the first pump starts running.
The above also applies to the subsequent pumps.
If the demand drops, the pressure rises to the first stop value, causing the pump to stop.
If the demand drops further, the last pump fills the tank and then shuts down.
Control panel QMD, QMY:
- Automatic sequential pump regulation with low-pressure control from pressure switches or sensors.
- Cyclic changeover of first pump to be started.
- Changeover lock selector switch.
- Delay to prevent simultaneous start-up.
- Short-circuit and overload protection via an automatic switch.
- Dry running protection via a pressure switch or float switch or level sensors with sensitivity adjustment
(accessory electrodes not included).
- Dry running protection cut-in timer.
- Shut-down delay timers on both pumps
- Output for dry contact relay card (accessory)
- Electromechanical selector switches for Automatic-Off-Manual operation (Inside panel)
The set is controlled by an electronic card (consult the relative manual).
14
0°C to +40 °C
0°C to + 40 °C
Max 8 bar, 10 bar, 16 bar depending on the type of pump (see instruc-
tions handbook)
According to NPSH curve and flow resistance; level should be raised by
a safety margin of at least 0.5 metres if water contains air.
The inlet pressure plus the pressure supplied by the pump against the clo-
sed valve must always be lower than the maximum operating pressure.
Do not exceed the number of starts per hour indicated in section 12.