Daikin AGZ120E User Manual (English)

Questions and Answers:

M
marcusfloydAug 15, 2025
What causes motor overload relays or circuit breakers to open in my Daikin AGZ120E?
- A
  Ashley SchaeferAug 15, 2025
  If motor overload relays or circuit breakers are opening in your Daikin Chiller, it could be due to a voltage imbalance or voltage being out of range, requiring correction of the power supply. Defective or grounded wiring in the motor can also cause this, necessitating compressor replacement. Loose power wiring or burnt contactors are other potential causes; check all connections and tighten them, replacing contactors if needed. High condenser temperature can also trigger this issue; refer to corrective steps for High Discharge Pressure.
C
chadgloverAug 22, 2025
Why is my Daikin AGZ120E Chiller's compressor noisy or vibrating?
- S
  Samuel WalkerAug 22, 2025
  A noisy or vibrating Daikin Chiller compressor can stem from several issues. It could be due to low lift or an inverted start, which may require control adjustments or condenser fan VFDs. Another cause might be the compressor running in reverse; check the unit and compressor for correct phasing. Improper piping or support on the suction or discharge lines can also lead to noise and vibration, necessitating relocation, addition, or removal of hangers. Worn compressor isolator bushings can be a source of the problem, requiring replacement. In more severe cases, the compressor may have a mechanical failure, which would also require replacement.
E
esaundersAug 25, 2025
What causes high discharge pressure in my Daikin AGZ120E?
- K
  kwrightAug 26, 2025
  High discharge pressure in your Daikin Chiller can result from several factors. Noncondensables in the system may be the cause; extract them using approved procedures or replace the charge. The circuit might be overcharged with refrigerant, requiring you to remove the excess and check liquid subcooling. Ensure the optional discharge shutoff valve is open. Incorrect condenser fan control wiring or a non-running fan can also lead to high pressure; correct the wiring or check the electrical circuit and fan motor, respectively. A dirty condenser coil or air recirculation could also be responsible; clean the coil or correct the recirculation issue.
L
lsmithAug 31, 2025
What to do if my Daikin AGZ120E Chiller compressor will not stage up?
- I
  ibooneSep 1, 2025
  If your Daikin Chiller compressor isn't staging up, it could be due to a defective capacity control, which would need replacement. Another possibility is a faulty sensor or wiring, also requiring replacement. Finally, the stages might not be set correctly for the application; adjust the controller settings accordingly.
K
Katherine HayesSep 4, 2025
Why are the compressor staging intervals too short on my Daikin Chiller?
- J
  Jessica WilkinsSep 4, 2025
  Short compressor staging intervals on your Daikin Chiller can be attributed to several factors. The control band may not be set properly, necessitating an adjustment of the controller settings for the application. A faulty water temperature sensor could be the cause, requiring replacement. Insufficient water flow can also lead to this issue; correct the flow. Other potential causes include rapid temperature or flow swings (stabilize the load), oversized equipment (evaluate equipment selection), the chiller being enabled with no load (evaluate BAS sequence and settings), or light loads (evaluate the need for HGBP or thermal inertia).
O
Oscar ThompsonSep 12, 2025
What causes the compressor thermal protection switch to open on my Daikin AGZ120E?
- A
  Angelica AllenSep 12, 2025
  The compressor thermal protection switch opening on your Daikin Chiller can be caused by several factors. It could be due to operating beyond design conditions, requiring correction to stay within allowable limits. A discharge valve not being open can also trigger this; ensure the valve is open. Short cycling can lead to this issue; stabilize the load or correct control settings for the application. Voltage range issues or imbalance can be responsible; check and correct the voltage. High superheat can also cause the switch to open; adjust to correct superheat. In some cases, compressor mechanical failure may be the cause, necessitating compressor replacement.

Daikin AGZ120E Specifications

General

Brand	Daikin
Model	AGZ120E
Category	Chiller
Language	English

Summary

Installation and Application Information

Operating and Standby Limits

Details the maximum and minimum operating and standby ambient and fluid temperature limits.

Unit Placement

Service Clearance

Spacing Requirements

Chilled Water Piping

Field installed water piping to the chiller must include

Essential components and considerations for field-installed chilled water piping.

Inlet Strainer Guidelines

Water Flow Limitations

Discusses constant and variable evaporator flow, and their impact on pressure drop.

Evaporator Freeze Protection

Details protection measures against evaporator freeze-up, including heaters and glycol.

Chilled Water Pump

Explains the importance of wiring and controlling chilled water pumps via the chiller's microprocessor.

Flow Switch

Describes the requirement and options for chilled water flow switches for unit protection.

Glycol Solutions

Electrical Data

Electrical Data Notes

Important notes regarding power wiring, wire sizing, and electrical connections.

Circuit Breakers

Voltage Limitations

Panel High Short Circuit Current Rating

Electrical Control Center

Power Connections

Unit Controller Operation

General Description

Overview of the MicroTech III controller's capabilities for efficiency and troubleshooting.

System Architecture

Details the components and connections within the unit's control system architecture.

Controller Inputs and Outputs

Lists and describes the analog and digital inputs and outputs for the main controller.

EXV Module 1 and 2

RapidRestore®

Set Points

Details on unit-level set points, their defaults, and adjustable ranges.

Dynamic Set Point Ranges

Circuit Level Set Points

Configuration settings applicable to each individual refrigerant circuit.

Security

Sequence of Operation

Figure 47: Unit Sequence of Operation - Cool Mode

Figure 50: Unit Sequence of Operation - Ice Mode

Unit Functions

Unit Capacity Control

Explains how unit capacity is managed through compressor staging.

Evaporator Pump Control

Freeze Protection

Describes measures to protect the evaporator from freezing.

LWT Target

RapidRestore® Option

Details the RapidRestore® option for faster restarts and improved loading.

Compressor Starts Per Hour

Sound Reduction

Circuit Functions

Calculations

Circuit Control Logic

Outlines the conditions required for enabling a circuit and compressor availability.

Circuit States

EXV Control

Explains the Electronic Expansion Valve control states and operation.

Superheat Target

Capacity Overrides – Limits of Operation

Conditions that override automatic capacity control to prevent abnormal operation.

Alarms

Unit Fault Alarms

Lists alarms related to unit-wide issues like power configuration and communication failures.

Unit Problem Alarms

Unit Warning Alarms

Circuit Fault Alarms

Lists fault conditions specific to individual refrigerant circuits.

Alarm Logs

Clearing Alarms

Using the Controller

Passwords

Instructions on entering passwords to access different parameter levels.

Navigation Mode

Edit Mode

Optional Low Ambient Fan VFD

Details the function of the VFD fan control for low ambient temperature operation.

VFD Interface

Table 83: Types of Alarms, Faults, and Errors

Startup and Shutdown Procedures

Pre Startup

Checklist and procedures required before initiating chiller startup.

Startup

Steps to follow for the initial startup of the chiller after pre-startup checks.

Shutdown

Procedures for temporary and extended shutdowns of the chiller unit.

Post Startup

Component Operation

Hot Gas Bypass (Optional)

VFD Low Ambient Control (Optional)

Details the optional VFD fan control for low ambient temperature operation.

Compressor Communications

Warnings and Alerts

Evaporator

Replaceable Core Filter-Driers

Crankcase Heaters

Unit Maintenance

General

Compressor Maintenance

All-Aluminum Condenser Coils

Cleaning Microchannel Aluminum Coils

Cleaning ElectroFin® Coated Coils

Routine Quarterly Cleaning of ElectroFin Coated Coil Surfaces

Filter-Driers

System Adjustment

Expansion Valve

R-410A Refrigerant

Safety

Safety precautions and handling guidelines for R-410A refrigerant.

POE Lubricants

Refrigerant Charging

Procedures for recharging the unit with R-410A refrigerant in the field.

Troubleshooting Chart

Compressor Will Not Run

Identifies possible causes and corrective steps for compressors that will not run.

Compressor Noisy Or Vibrating

Troubleshooting steps for noisy or vibrating compressors.

High Discharge Pressure

Addresses causes and solutions for high discharge pressure issues.

Low Suction Pressure

Troubleshooting guide for low suction pressure conditions.

Compressor Will Not Stage Up

Diagnoses and corrects issues related to compressors failing to stage up.

Compressor Staging Intervals Too Short

Warranty Registration Form (Scroll)

I. PRE START-UP PROCEDURE

II. Pre Start-Up Checklist

A checklist of items to verify before the unit's initial startup.

III. REFRIGERATION SYSTEM

IV. DESIGN CONTROLS

V. START-UP

Checks to ensure the unit starts and operates correctly per sequence.

MICROTECH STATUS CHECK-Each Reading Must be Verified with Field Provided Instruments of Known Accuracy?

VI. MICROTECH SETPOINTS

Limited Product Warranty

DAIKIN APPLIED AMERICAS INC. LIMITED PRODUCT WARRANTY (North America)

Company's warranty terms for defective parts, labor, and exclusions.

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Daikin AGZ120E User Manual

Table of Contents

Questions and Answers:

Daikin AGZ120E Specifications

Summary

Installation and Application Information

Operating and Standby Limits

Unit Placement

Service Clearance

Spacing Requirements

Chilled Water Piping

Field installed water piping to the chiller must include

Inlet Strainer Guidelines

Water Flow Limitations

Evaporator Freeze Protection

Chilled Water Pump

Flow Switch

Glycol Solutions

Electrical Data

Electrical Data Notes

Circuit Breakers

Voltage Limitations

Panel High Short Circuit Current Rating

Electrical Control Center

Power Connections

Unit Controller Operation

General Description

System Architecture

Controller Inputs and Outputs

EXV Module 1 and 2

RapidRestore®

Set Points

Dynamic Set Point Ranges

Circuit Level Set Points

Security

Sequence of Operation

Figure 47: Unit Sequence of Operation - Cool Mode

Figure 50: Unit Sequence of Operation - Ice Mode

Unit Functions

Unit Capacity Control

Evaporator Pump Control

Freeze Protection

LWT Target

RapidRestore® Option

Compressor Starts Per Hour

Sound Reduction

Circuit Functions

Calculations

Circuit Control Logic

Circuit States

EXV Control

Superheat Target

Capacity Overrides – Limits of Operation

Alarms

Unit Fault Alarms

Unit Problem Alarms

Unit Warning Alarms

Circuit Fault Alarms

Alarm Logs

Clearing Alarms

Using the Controller

Passwords

Navigation Mode

Edit Mode

Optional Low Ambient Fan VFD

Optional Low Ambient Fan VFD

VFD Interface

Table 83: Types of Alarms, Faults, and Errors

Startup and Shutdown Procedures

Pre Startup

Startup

Shutdown

Post Startup

Component Operation

Hot Gas Bypass (Optional)

VFD Low Ambient Control (Optional)

Compressor Communications

Warnings and Alerts

Evaporator

Replaceable Core Filter-Driers