To Next PageTo Next PageWhat causes a McQuay Chiller compressor thermal switch to open?
If the thermal switch on your McQuay Chiller's compressor opens, it could be because the unit is operating beyond its design conditions. Consider adding facilities to ensure conditions are within allowable limits.
Describes the McQuay air-cooled scroll compressor water chillers as self-contained refrigerating units.
Instructions for checking units for damage and verifying nameplate information upon arrival.
Notes that installation must be performed by trained, experienced personnel familiar with codes.
Guidance on careful handling of the unit, using lifting slots and spreader bars.
Details on mounting units on roofs or ground level, foundation requirements, and orientation relative to wind.
Information on ensuring accessibility to end-mounted components like compressors and control boxes.
Guidance on reducing noise transmission in sound-sensitive areas using isolation techniques.
Recommendations for installing water piping, including vibration eliminators, shutoff valves, and air vents.
Importance of adequate water volume for chiller stabilization and avoiding operational problems.
States that variable chilled water flow systems are not recommended for this equipment.
Instructions on mounting and connecting a water flow switch to shut down the unit if flow is interrupted.
Details on the unit's 3-inch holes for chilled water piping entry and insulation requirements.
Information on the operating charge for R-22 or R-407C units and where to find specific data.
Diagram showing the location of key components within the unit.
Explains how glycol affects unit capacity and pressure drop, and how to measure flow and pressure.
Details on POE lubricants, their properties, and handling precautions for R-407C units.
Procedures for determining superheat and subcooling for R-407C, referencing P/T charts.
Notes that software settings are factory-set for R-407C to account for pressure/temperature differences.
Guidance on recharging R-407C units, including handling refrigerant as a liquid and initial charge amounts.
Description of the weatherproof control center, its sections, and components.
Procedures and checks for unit start-up and shutdown sequences.
Checklist of procedures before unit start-up, including flushing, checks, and waiting period.
Steps to set temperature controller and Delta-T to initiate the unit start-up sequence.
Details on unit start-up sequence, compressor staging, and checks after running.
Lists conditions that shut down or limit unit operation, such as no water flow or high pressure.
How to enable unit operation via keypad, digital input, or Building Automation System.
Options for selecting unit operation mode (cooling, ice, glycol, test).
How the MicroTech II controller manages condenser fans based on discharge pressure.
Describes the sequence for normal unit shutdown, including compressor staging and crankcase heaters.
Table of physical data for AGZ-BS packaged chillers, including dimensions, weights, and capacities.
Table of physical data for larger AGZ-BS packaged chillers, covering capacities and specifications.
Table of physical data for AGZ-BM remote evaporator units, listing dimensions and weights.
Table of physical data for larger AGZ-BM remote evaporator units, including capacities and specifications.
Guidance on field wiring, compliance with codes, and power connection requirements for AGZ units.
Electrical data table for AGZ units using R-22 refrigerant, detailing power supply and wiring.
Table showing amp draw for compressors and fan motors for R-22 units.
Field wiring data for R-22 units, covering terminal amp ratings, disconnect sizes, and breaker types.
Electrical data table for AGZ units using R-407C refrigerant, detailing power supply and wiring.
Amp draw table for compressors and fan motors for R-407C units.
Field wiring data for R-407C units, including terminal amp ratings, disconnect sizes, and breaker types.
Clarifications on RLA and FLA values used for wiring and fan motor amp calculations.
Clarifications on disconnect requirements, wire material, and wire size temperature rating.
Diagram showing dimensions and weight information for AGZ 010BS to 017BS packaged units.
Diagram showing dimensions and weight information for AGZ 020BS to 034BS packaged units.
Diagram showing dimensions and weight information for AGZ 010BM to 017BM remote evaporator units.
Diagram showing dimensions and weight information for AGZ 020BM to 034BM remote evaporator units.
Diagram and table detailing dimensions and connection sizes for remote evaporators.
Table listing dimensions and weights for AGZ packaged chillers.
Table listing dimensions and weights for AGZ remote evaporator units.
Table showing mounting corner weights for remote evaporator units.
General guidance on routine service checks and electric leg readings.
Notes that AGZ units require no routine lubrication and fan motor bearings are permanently lubricated.
Warning about electrical shock hazard and the need to retighten power electrical terminals every six months.
Information on condenser construction, cleaning, and maintenance requirements.
Monthly observation of the sight glass for refrigerant charge, moisture, and potential restrictions.
States the manual covers Software Release AGZ SU0102D.
Highlights the controller's self-diagnostic checks, alarms, and security features.
Explains how compressors are staged based on leaving chilled water temperature.
Details the solid-state motor protector module and its 2-minute time-off delay.
Explains FanTrol for head pressure control, cycling fans based on condenser pressure.
Lists analog and digital inputs/outputs and their signal sources/ranges.
Table detailing default values, ranges, and password requirements for various setpoints.
Setpoints that have ranges limited by unit options.
Automatic ranges for LWT setpoints based on unit mode.
Automatic ranges for freeze protection temperature based on unit mode.
Automatic ranges for low ambient lockout based on SpeedTrol option.
Automatic ranges for low evaporator pressure settings based on refrigerant and unit mode.
Notes that some setpoints have dynamic default values based on other settings.
Table detailing shutdown alarms, their causes, actions taken, and reset methods.
Table describing limit alarms, their conditions, actions, and reset criteria.
Definition and calculation of the control band used in staging logic.
How the leaving water reset input adjusts the leaving water setpoint.
Definition of the active leaving water temperature setpoint, considering unit mode and reset.
Equation for calculating LWT error.
Calculation of LWT slope over a one-minute timeframe.
Defines how saturated temperatures are calculated for R22, referencing line segments.
Defines how saturated temperatures are calculated for R407C using specific equations.
How low evaporator pressure affects compressor staging.
Conditions required for a compressor to be available to start.
Determines when compressors start or stop based on various conditions.
Logic flag set when conditions are met to start another compressor.
Description of the controller's display and keypad layout.
Basic procedures for using the controller, including navigating menus.
Explains how to navigate the menu matrix using ARROW keys and MENU key.
Function of the MENU key for switching between shortcut and scrolling modes.
General information about menu screens, their content, and arrangement.
Steps for editing and changing setpoints using the controller keypad.
Explanation of the hierarchical menu structure and navigation.
Definition of the VIEW UNIT screen, showing status and parameters.
Details on unit status screens showing timer values.
Details on unit status screens showing digital inputs/outputs.
Definition of the VIEW UNIT TEMP screen showing temperature readings.
Definition of the VIEW UNIT TEMP screen showing pulldown rate and control band.
Definition of the VIEW UNIT TEMP screen showing staging parameters.
Screen for viewing compressor status, cycle timers, and manual disable.
Screens showing refrigerant pressures, temperatures, and approach for R22 and R407C.
Screen showing fan stage status.
Screens indicating active alarms and how to clear them.
Instructions on how to change unit setpoints using the controller.
Setpoints for anti-recycle timers (Clear Cycle Tmr, Stop-Start, Start-Start).
Setpoints for inter-stage up and down delays for compressor staging.
Setpoints for enabling/disabling individual compressors.
Alarm limit setpoints for Low Evaporator Pressure (Hold, Unload).
Alarm limit setpoints for Evaporator Freeze and Evap Flow Proof.
Alarm limit setpoints for High Condenser Pressure (Unload, Stop).
Alarm limit setpoints for Phase Voltage and Low OAT Lockout Timer.
Setpoints for fan stages and SpeedTrol option.
Setpoints for fan stage ON pressures.
Setpoints for fan stage OFF pressures.
Test screen for controlling Alarm Signal and Evap Water Pump.
Test screen for controlling Liquid Line Solenoid and Compressors.
Test screen for controlling Fan Motors.
Function and adjustment of the thermostatic expansion valve for maintaining superheat.
Monitoring and changing filter-driers based on pressure drop.
Maintenance of the liquid line solenoid valve, including coil replacement.
Operation of SpeedTrol for variable speed fan control to maintain head pressure.
System for maintaining evaporator pressure and oil return at light load conditions.
Diagram illustrating the piping for the hot gas bypass system.
Graph showing the adjustment range for the remote bulb on the hot gas bypass valve.
Illustration of the hot gas bypass valve and its adjusting screw.
A chart listing common problems, their possible causes, and corrective steps.
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