Vertiv Liebert CRV4 Series

Taylor RiveraSep 14, 2025

What does it mean if the suction and exhaust pressures do not change after startup in Vertiv Air Conditioner?

K
Katie EatonSep 15, 2025
If the suction and exhaust pressures of your Vertiv Air Conditioner do not change after startup, it indicates that either the compressor is reversed or the internal air tightness of the compressor has failed. If the compressor is reversed, exchange any two L lines of the compressor. If the internal air tightness of the compressor has failed and cannot be restored, replace the compressor.

Refrigerant	R410A
Compressor Type	Scroll
Airflow	Varies by model
Sound Pressure Level	Varies by model
Dimensions (HxWxD)	Varies by model
Weight	Varies by model

Refrigerant

R410A

Compressor Type

Scroll

Airflow

Varies by model

Sound Pressure Level

Varies by model

Dimensions (HxWxD)

Varies by model

Weight

Varies by model

Summary

Purpose of the Document

Styling used in this Guide

Defines the visual styles used for notes and warnings within the manual.

Version History

Lists the historical versions of the user manual.

Chapter 1: Introduction

1.1. Product Introduction

Introduces the Liebert CRV4 series as a next-gen precision air conditioner for data centers.

1.2. Model Nomenclature

Explains the twenty-five digit model nomenclature and refers to Table 1-1.

1.3. Product Appearance

1.4. Main Components

Details the key components of the Liebert CRV4 indoor unit, including compressor, evaporator, etc.

1.4.1. EC Compressor

Describes the scroll compressor features: low noise, vibration, high reliability, efficiency.

1.4.2. Evaporator

Describes the 7mm copper tube finned evaporator with distributor for even refrigerant distribution.

1.4.3. Electronic Expansion Valve (EEV)

Modulates refrigerant mass-flow using temp/pressure signals for precise regulation.

1.4.4. Electrode Humidifier

Simple structure, large humidifying volume, high efficiency, easy disassembly.

1.4.5. EC Fan

High efficiency, energy saving, space saving, and hot-swappable design.

1.4.6. Electrical Heater

Uses PTC heater for fast heating, even heat distribution, safe & reliable working.

1.4.7. Sight Glass

Observes refrigerant state and moisture content; color changes if moisture exceeds standard.

1.4.8. Filter Dryer

Eliminates system moisture and filters impurities for normal operation.

1.4.9. Display Screen

7-inch HMI color/LCD screen, simple UI, password protection, auto-restoration.

1.4.10. Remote Monitoring Software

Uses Modbus protocol via RS485 port for communication with host computer.

1.5. Options

1.5.1. Air Pressure Difference Switch

Detects clogged filters and sends alarm signals.

1.5.2. Water Leakage Detection Kit

Detects water under-floor and sends alarm signals to the control board.

1.5.3. Remote Temperature Sensor Kit

Monitors other device temperatures in the room for unit control.

1.5.4. Monitoring Card

RDU-SIC card provides RJ45 and USB ports for monitoring via Web or NMS.

1.5.5. Dual Power Module

Provides high efficiency dual power with minimum electrical losses for reliability.

Chapter 2: Installation

2.1. Equipment Room Consideration

Requirements for preparing the equipment room for smooth operation and data center standards.

2.2. Installation Space Requirements

Specifies clearances for installing the unit with server cabinets for cold/hot aisle configuration.

2.2.1. Maintenance Space Requirements for Liebert CRV4

Specifies 600mm front/rear space for maintenance activities like filter/fan replacement.

2.3. Environmental Requirements

Details ambient temperature, protection level, altitude, and operation voltage range.

2.3.1. Operating Environment

Details ambient temperature, protection level, altitude, and operation voltage range.

2.3.2. Storage Environment

Specifies storage conditions: indoor, clean, no dust, humidity, and ambient temperature.

2.4. Refrigerant Charging Requirement

Unit requires specific R410A quality refrigerant for optimal efficiency.

2.5. Transportation, Unpacking and Inspection

Covers procedures for safe transport, unpacking, and initial inspection of the unit.

2.5.1. Transportation and Movement

Recommends railroad/ship transport; road transport requires smooth roads.

2.5.2. Unpacking

Provides step-by-step instructions for removing wooden packaging and pallet.

2.5.3. Inspection

Check fittings and components against packing list for completeness and intactness.

Chapter 3: Mechanical Installation

3.1. System Arrangement during Installation

Details the overall system arrangement for the refrigeration system.

3.1.1. General Arrangement

Shows the system arrangement diagram of the refrigeration system for Liebert CRV4.

3.1.2. System Installation Mode

Shows installation modes with outdoor unit placed higher or lower than compressor.

3.1.3. Mechanical Parameters

Displays mechanical parameters and dimensions (W x D x H) and net weight of indoor units.

3.1.4. Base Plate Piping Location and Dimensions

Shows inlets and outlets for piping on the unit base plate.

3.1.5. Top Plate Piping Locations & Dimensions

Shows pipe inlets and outlets on the unit top plate for down pipe outlets and up pipe outlets.

3.1.6. Location of Front Air Outlets

Illustrates the location of air outlets at the front of CR025, CR035, and CR045 models.

3.2. Installation of the Indoor Unit

Covers the process of installing the indoor unit, including leveling and fastening.

3.2.1. Leveling the Cabinet

Step-by-step illustration of the process for leveling the cabinet using leveling feet.

3.2.2. Removing the Leveling Feet and Fastening

Instructions for removing leveling feet and fixing the cabinet using fixing holes.

3.2.3. Assembly of the Cabinet Parts

Details assembling cabinet parts and using cabinet connectors to join adjacent cabinets.

3.3. Unit Piping Installation

Outlines the four kinds of piping to be joined: condensate, humidifier, copper, long piping kit.

3.3.1. Removing Filter Net

Instructions for removing filter nets from the top and bottom panels of the unit.

3.3.2. Connecting the Condensate Water Drainage Piping of the Indoor Unit

Details connecting condensate water drainage piping for bottom and top piping connections.

3.3.3. Electrode Humidifier Water Inlet Piping Connection

Connects water inlet pipes from the bottom or top to the electrode humidifier.

3.3.4. Connection of the Copper Piping between the Indoor and Outdoor Units

Connects indoor and outdoor units via brazed copper piping, specifying pipe dimensions and slope.

3.3.5. Installing Long Piping Kit (for site installation)

Instructions for installing long piping kits when equivalent pipe length exceeds 30m or vertical distance is large.

3.3.6. Check Valve Installation

Instructions for installing the check valve, ensuring arrow points towards the outdoor unit.

3.3.7. Installing the Solenoid Valve

Instructions for mounting the solenoid valve horizontally, ensuring arrow points towards the indoor unit.

3.4. Charging Refrigerant and Adding Lubricant Oil

Covers procedures for charging refrigerant and adding lubricant oil to the system.

3.4.1. Charging Refrigerant

Details standard refrigerant charge amounts for outdoor and indoor units and calculation formula.

3.4.2. Adding Lubricant Oil

Explains the type of lubricant oil used and the amount to be added based on pipe OD and length.

3.5. Removing Transportation Fastener and Vibration Absorber

Details removal of transit fasteners and vibration absorbers before installation.

Removing retaining metal plates to fix the compressor in transit

Describes removal of retaining metal plates mounted on compressor feet for transit protection.

Removing pipe fastener

Removal of vibration absorbers fitted between copper pipes and metal plates.

Removing limiting piece of the electrical control box

Removal of a limiting piece in the electrical control box for maintenance access.

Adjusting the supply air baffle

Adjusting the installation direction of the supply air baffle to direct airflow left or right.

3.5.1. Sealing the Holes of the Top Plate of the Cabinet

Sealing reserved holes on the top plate using rubber plugs and bolts to prevent water entry.

3.6. Checklist for Completed Mechanical Installation

Checklist to verify successful mechanical installation of equipment, piping, and fasteners.

Chapter 4: Electrical Installation

4.1. Task Introduction and Notes

Introduces electrical installation tasks and provides important notes and safety guidelines.

4.1.1. Cables to Connect On-site

Lists on-site cables to connect: power, control, outdoor unit, solenoid valve.

4.1.2. Installation Notes

Compliance with regulations, cable sizing, mains supply requirements, safe practices.

4.2. Liebert CRV4 Cable Connection of Indoor Unit

Details connecting various cables to the indoor unit.

4.2.1. Electrical Port Location of the Indoor Unit

Shows layout and locations of low voltage components by opening the rear panel.

4.2.2. Connecting the Power Cable of the Indoor unit

Connects supply terminals L1-L3, N, PE to counterparts and fixes cables to clamp.

4.2.3. Connecting the Control Cables

Shows terminal block location for on-site cable connections and enlarged view of terminals.

4.2.4. Water-under-floor Sensor

Connects sensor to terminal 51# and common terminal 24# for water detection.

4.2.5. SIC Card

Connects SIC card terminals A#, B#, GND#, 12# to respective terminal block counterparts.

4.2.6. Rack Temperature Sensor

Connects up to 6 sensors, recommends placement in front of heat-loads for precise temp.

4.2.7. Remote Shutdown

Connects terminals 37# and 38# to remote shutdown switches; closing them shuts down the unit.

4.2.8. Control Signals of the Outdoor Unit

Terminals 70# & 71# are for outdoor unit control signal input, compressor rotation speed.

4.2.9. External General Alarm

Terminals 75# and 76# connect to external alarms for indicators or building management systems.

4.2.10. Connecting the Solenoid Valve of the Long Piping Kit- (Optional for site installation)

Solenoid valve consists of two control cables connected to respective terminals on control board.

4.2.11. Teamwork Control

Connects communication cables to terminals 61# & 62# on TB2 terminal block for teamwork control.

4.3. Electrical Installation Checklist

Checklist to confirm electrical installation particulars like voltage, connections, MCB ratings.

Chapter 5: Start-up Commissioning

5.1. Location Of MCBs

Shows locations of MCBs for compressor, heater, transformer, fan, and humidifier.

5.2. Power-On Commissioning

Covers procedures for powering on and commissioning the unit.

5.2.1. Preparation Before Commissioning

Includes mechanical checks (valves, piping, refrigerant) and electrical checks (voltage, connections).

5.2.2. Commissioning Procedures

Steps for turning on MCBs, checking fans, vacuuming the system, and charging refrigerant.

4. Charging refrigerant

Details static and dynamic charging procedures for refrigerant, including safety notes.

5.3. Inspection After Commissioning

Checklist for Vertiv engineers to confirm functional outputs, settings, and absence of alarms.

Chapter 6: Micro-Controller (Color Screen)

6.1. Features

Micro-controller features: monitoring, 7-inch HMI, password protection, fault diagnosis.

6.2. Appearance

Describes the unit's 7-inch HMI color display appearance.

6.3. Control Screen

Details the control screen interface and its various modes.

6.3.1. Main Screen

Describes the main interface after startup, including menu, settings, and status displays.

6.3.2. Main Interface Control Mode

Explains temperature/humidity control modes, values, and status indicators on the main interface.

6.3.3. Password Interface

Shows the password interface screen for accessing menus with three password levels.

6.4. Menu Structure

Outlines the structure of the controller's menu system.

6.4.1. Main Menu

Describes accessing the Main Menu after entering correct password credentials and highlights selected menu items.

6.4.2. Run Information

Displays temp/humidity, switch status, power info, and teamwork info within the Run Information menu.

Switch status

Displays the switch status of each electrical component.

Power Information

Displays the three-phase voltage and frequency.

Teamwork Information

Displays the status of the group information.

6.5. Alarm Information

Provides access to current and historical alarm data.

Alarm Status

Monitors active alarm status, showing alarm number and total active records.

Alarm History

Queries historical alarm information, showing current history alarm number and total records.

6.5.1. Temperature and Humidity

Interface to set supply air temp, return air temp, remote temp, and temp difference.

Temp Setting

Interface to set supply air, return air, remote air temperatures, and temp difference.

Hum Setting

Sets the humidity setting value for the unit.

6.5.2. Parameter Setting

Allows configuration of various system parameters.

Alarm Setpoint

Sets alarm setpoints for high/low temperature and humidity.

Alarms Attribute

Enables or disables alarm attributes for various conditions.

Communication Setting

Configures monitoring protocol, baud rate, and monitor address.

Teamwork Setting

Configures teamwork settings like unit address and quantity.

Time Setting

Sets the date and time for the unit.

Display Setting

Adjusts display contrast and language.

Password Setting

Manages passwords for different access levels.

6.5.3. Graph

Queries curves for return/supply temperature and humidity over 0-48 hours.

6.5.4. About

Displays software model and version numbers.

Chapter 7: Micro-Controller (Text-screen)

7.1. Features

Micro-controller features: monitoring, 128x64 LCD, password protection, fault diagnosis.

7.2. Appearance

Describes the appearance of the micro-processing controller panel.

7.3. Graphic Color Screen

Describes the LCD screen, default language, and displays of temp, humidity, and status.

7.4. Control Buttons

Details the functions of the control buttons.

7.4.1. Function Description

Detailed functions of the five control buttons: On/Off, Enter, ESC, Up, Down.

7.4.2. Operational Examples

Step-by-step examples for accessing the Main Menu and setting parameters.

7.5. Control Screen

Details the control screen interface and its displays.

7.5.1. Startup Screen

Displays the 'Connecting...' screen after the system is powered on.

7.5.2. Main Screen

Displays temp, humidity, and unit output/operation status after startup.

7.5.3. Password Interface

Shows password interface and lists three password levels for menu access.

7.6. Menu Structure

Outlines the structure of the controller's menu system.

7.6.1. Main Menu

Describes accessing the Main Menu after correct password entry and highlights selected menu items.

7.6.2. Run Information

Displays temp/humidity, ESP, power, and teamwork info within the Run Information menu.

Temperature & Humidity Information

Displays detailed temperature and humidity readings for various sensors.

ESP Information

Displays ESP (Equivalent Static Pressure) average and individual readings.

Power Information

Displays three-phase voltage and frequency readings.

Teamwork information

Displays status of group information for teamwork control.

7.6.3. Alarm Information

Provides access to current and historical alarm data.

Alarm Status

Monitors active alarm status, showing alarm number and total active records.

Alarm History

Queries historical alarm information, showing current history alarm number and total records.

7.6.4. Temperature & Humidity Settings

Interface to set supply air temp, return air temp, remote temp, and temp difference.

Temp Setting

Interface to set supply air, return air, remote air temperatures, and temp difference.

Hum Setting

Sets the humidity setting value for the unit.

7.6.5. Parameter Settings

Allows configuration of various system parameters.

Alarm Setpoint

Sets alarm setpoints for high/low temperature and humidity.

Alarms Attribute

Enables or disables alarm attributes for various conditions.

7.6.6. Alarm Set

Configures alarm parameters and settings.

7.6.7. Humidifier Set

Configures humidifier type and settings.

7.6.8. Teamwork Set

Configures teamwork settings like unit address and quantity.

7.6.9. ESP Set

Sets the ESP (Equivalent Static Pressure) parameters.

7.6.10. Display Set

Adjusts display contrast and language.

7.6.11. Password Set

Manages passwords for different access levels.

7.6.12. Help

Displays software model and version numbers.

Chapter 8: System Operation and Maintenance

8.1. Routine Maintenance & Inspection Items (Monthly)

Checklist for monthly checks of filter, fan, compressor, condenser, and refrigeration system.

8.2. Routine Maintenance and Inspection (Semi-annually)

Checklist for semi-annual checks of air filter, fan, compressor, condenser, refrigeration, heating, and electrical parts.

8.3. Self-Diagnosing Functions

Built-in diagnostic function to check component functionality.

8.4. Maintenance of Electrical Control Utilities

Covers maintenance procedures for electrical parts and control systems.

8.4.1. Maintenance of Electrical Parts

Visual checks and handling for electrical connections, contactors, and components.

8.4.2. Maintenance of Control System

Checks power transformers, control boards, sensors, connections, and simulates protecting units.

8.4.3. Water-Leak-Detector

Describes water leak detector placement and alarm confirmation via controller.

8.5. Air Filter Maintenance

Filter efficiency standards, setting maintenance logic, and checking/replacing filters.

8.6. Fan Kit Maintenance

Checking EC fans, inspecting motor, impeller, clearance, and fan replacement procedure.

8.7. General Maintenance for the Electrode Humidifier

Covers maintenance guidelines for the electrode humidifier.

8.7.1. Operating Guidelines for the Electrode Humidifier

Describes humidifier kit components and how the micro-controller initiates humidification.

8.7.2. Replacing Humidifier

Procedures for replacing the humidifier, including cleaning the tray and emptying the unit.

8.8. Electrical Heater Maintenance

Monitoring optional heaters, checking for dust/debris, inspecting functionality, and replacement.

8.9. Refrigerating System Maintenance

Provides instructions for maintaining the refrigerating system.

8.9.1. Suction Pressure

Explains suction pressure impact on compressor and lists min/max pressures.

8.9.2. Discharge Pressure

Explains discharge pressure changes and its relation to high pressure switch.

8.9.3. Electronic Expansion Valve (EEV)

Automatic regulation of EEV for refrigerant supply and superheat measurement.

8.9.4. Air-cooled Condenser

Cleaning condenser, inspecting fins, and checking refrigeration lines for leaks.

8.9.5. Compressor

Safety notes for compressor replacement, causes of motor burn, and periodic checks.

Mechanical faults

Diagnosing mechanical faults, replacing compressor, and cleaning the system.

Electrical faults

Identifying electrical faults, cleaning system, and replacing filter dryer/expansion valve.

8.10. Drainage System Maintenance

Inspects water tray, ensures no sediments/debris, and cleans water tray filter.

Chapter 9: Troubleshooting

9.1. Troubleshooting of the Fan

Details symptoms, possible causes, and items to check for EC fan failure.

9.2. Troubleshooting of the Heating System

Troubleshooting heating system: no start, contactor closes but no heating.

9.3. Troubleshooting of Compressor and Cooling System

Troubleshooting compressor: no start, contactor doesn't close, stops after running.

Vertiv Liebert CRV4 Series - User Manual

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