5.5kW 380V VFD for a Hotel Booster Pump System in Thailand

Application reference image for engineering context. It is not presented as the customer site photo.

Introduction

A hotel water system contractor in Thailand needed a VFD solution for a 5.5kW booster pump. The main requirement was stable water pressure for guest rooms and service areas while avoiding hard starting and unnecessary full-speed operation.

Based on the inquiry data available for this draft, AUSENIST recommended a 380V pump VFD with PID pressure control and analog pressure feedback. The final model must still be confirmed by the actual motor rated current and site control requirements.

Project Overview

Item	Project Requirement
Country	Thailand
Customer Type	Hotel water system contractor
Application	Hotel domestic water booster system
Pump Type	Booster pump
Motor Power	5.5kW
Motor Voltage	380V three-phase
Power Supply	380V three-phase
Control Requirement	Constant pressure
Pressure Sensor	Analog pressure transmitter recommended
VFD Model	AUSENIST 380V pump VFD, 5.5kW class
Control Method	PID pressure control

Customer Requirement

The customer needed the pump to adjust speed automatically when water demand changed. A hotel system may have low demand at night, normal demand during the day and peak demand in the morning or evening.

The buyer needed a constant pressure VFD configuration that could be commissioned by a local technician using motor nameplate data and a correctly scaled pressure transmitter.

Technical Challenge

Hotel booster systems are sensitive to pressure fluctuation. A drive selected only by kW may still perform poorly if the pressure sensor range, PID target, minimum frequency or sleep/wake logic is not set correctly.

The pump must also avoid rapid cycling. If the system includes a pressure tank, the tank pre-charge and VFD sleep/wake settings should be coordinated during commissioning.

VFD Selection

Based on the information provided by the customer, the recommended direction is a 5.5kW 380V pump VFD with PID constant-pressure control. The VFD output current must match the actual motor nameplate.

AUSENIST should confirm:

• Motor rated current and voltage.
• Required pressure range for the hotel system.
• Pressure transmitter signal and range.
• Whether the system uses one pump or multiple pumps.
• Whether sleep/wake operation is required.

If the booster system includes multiple pumps, the control method should define lead pump, assist pump, alternation and fault handling.

Recommended Solution

Item	Recommended Configuration
VFD Model	AUSENIST 380V pump VFD, 5.5kW class
Rated Power	5.5kW, subject to motor current confirmation
Input	380V three-phase
Output	380V three-phase
Control Mode	PID constant-pressure control
Pressure Feedback	Analog pressure transmitter
Optional Accessories	Pressure sensor, pressure tank coordination, input or output reactor if required

The VFD receives pressure feedback from the outlet pipeline. It compares the feedback value with the target pressure and adjusts pump speed. When demand is low, the drive may reduce frequency and enter sleep mode if configured.

System Operating Logic

Pressure sensor
↓
Analog feedback to VFD
↓
PID pressure comparison
↓
Pump speed adjustment
↓
Stable hotel water pressure

Recommended Initial Parameters

Parameter	Recommended Setting
Motor Rated Power	5.5kW
Motor Rated Voltage	380V
Motor Rated Current	Set according to actual nameplate
Maximum Frequency	According to motor and pump rating
Minimum Frequency	Confirm from pump curve and hotel pressure demand
Acceleration Time	Set to reduce water hammer
Deceleration Time	Set to avoid pressure shock
PID Target	Set according to required hotel pressure
Pressure Feedback	Match transmitter range and signal

Final settings should be adjusted according to the actual motor nameplate, pump curve and site conditions.

Expected Operating Behavior

The VFD is expected to regulate pump speed according to water demand and maintain pressure more smoothly than fixed-speed operation. The installer should verify pressure stability, current, sleep/wake behavior and sensor scaling during commissioning.

No actual running data was provided, so this article does not claim verified pressure improvement or energy savings.

Engineering Notes

• Pressure transmitter range should match the hotel water pressure requirement.
• Minimum frequency should not be guessed.
• Sleep/wake settings should be tested to avoid short cycling.
• Check the pressure tank setting if one is installed.
• Final selection must use motor rated current, not only 5.5kW.

FAQ

Is a VFD suitable for hotel booster pumps?

Yes, when the pump and motor are suitable and the pressure feedback loop is commissioned correctly.

What sensor is used for hotel constant pressure?

An analog pressure transmitter is normally used. Its signal and measuring range must match the VFD input and the system pressure.

Can one VFD control a multi-pump hotel system?

Multi-pump control requires a defined architecture. In many systems, each motor has its own drive and the pumps are coordinated by drive logic or an external controller.

Have a Similar Pump Application?

If you are selecting a VFD for a hotel booster system, send us the motor nameplate, pump quantity, power supply, required pressure, sensor type and control sequence.

AUSENIST can recommend the appropriate VFD model and control configuration.

Target Keywords:

5.5kW hotel booster pump VFD, 380V booster pump inverter, constant pressure hotel water pump, PID pump VFD, pump inverter Thailand

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Approximately 7,200 characters.