McQuay WME 0500 Installation Manual

Operation & M a intenance Manual

OMM 1034-2

Group: Chiller
Part Number: 331499501
Effective: July 2012
Supersedes: May 2012

Magnitude Magnetic Bearing Centrifugal Chillers

Model WME 0500 - 700

Software Version: 4.22.3

CAUTION

WARNING

Warnings indicate potentially hazardous situations, which can result in property damage, severe personal injury, or death if not

DANGER

Table of Contents

Introduction ................................................3

Trend Screens ...................................................... 44

Operating the Chiller .............................. 45

Features of the Control Panel ...................8

General Description ...................................9

Component Description ...........................10

Operator Interface Touch Screen .........................10

Unit Controller .....................................................10

Motor/Compressor Controller .............................. 11

VFD Controller .................................................... 11

VFD Description: ................................................. 11

Key VFD Control Signals ....................................12

Inputs and Outputs ...............................................12

Optional Harmonic Filter ........................15

Field Control Wiring Diagram................16

Operator Interface Touch Screen (OITS)17

Navigation ............................................................17

SET Screens .........................................................23

Service Screens ....................................................38

Downloading Data ...............................................39

Chiller Faults and Alarms .....................................40

Event Types .........................................................40

Recognize Safety Symbols, Words, and Labels

The following symbols and labels indicate immediate or potential hazards. Read and comply with all safety information
and instructions accompanying these symbols. Failure to heed safety information increases the risk of property and/or
product damage, serious injury or death. Improper installation, operation and maintenance can void the warranty.

Interface Panel On/Off ........................................ 45

Start/Stop Unit ..................................................... 45

Changing Setpoints ............................................. 45

Sequence of Operation ............................ 45

Troubleshooting ....................................... 47

Operation with Failed OITS ................................ 48

Maintenance............................................. 49

External Sensors and Valve Locations ................ 49

Routine Maintenance........................................... 52

Annual Shutdown ................................................ 55

Annual Startup .................................................... 55

Repair of System ................................................. 55

Maintenance Schedule ............................ 58

Service Programs ..................................... 60

Operator T raining ................................... 60

Warranty Statement ................................ 60

Cautions indicate potentially hazardous situations, which can result in personal injury or equipment damage if not avoided.

avoided.

Dangers indicate a hazardous situation which will result in death or serious injury if not avoided.

©2012 McQuay International. Illus trations and data cover the McQuay International produc t at the time of public ation and we reserve the right to
make changes in design and construction at anytim e without notice. ™® The following are trademarks or registered trademarks of thei r respective
companies: BACnet from ASHRAE;
International under a license granted by E chelon Corporation; Modbus from Schnei der E l ectric; Victaulic from Victaulic Company; Magnitude,
Energy Analyze, MicroTech E, Open Choices from McQuay International.

2 OMM 1034-2

LONMARK, LonTalk, LONWORKS, and the LONMARK logo are managed, granted and used by LONMARK

!

WARNING

!

CAUTION

!

CAUTION

Introduction

This manual provides operating, maintenance and troubleshooting information for the Daikin McQuay Magnitude
frictionless centrifugal chiller with magnetic bearing compressor, Model WME, with MicroTech® E control.

Electric shock hazard. Can cause personal injury or equipment damage. This equipment must be properly grounded. Connections to

and service of the MicroTech control panel must be performed only by personnel that are knowledgeable in the operation of the

equipment being controlled.

Static sensitive components. A static discharge while handling electronic circuit boards can damage components. Discharge any
static electrical charge by touching the bare metal inside the control panel before performing any service work. Never unplug any
cables, circuit board terminal blocks, or power plugs while power is applied to the panel.

Do not install any software not authorized by McQuay International or alter operating systems in any unit microprocessor, including
the interface panel. Doing so can cause malfunction of the control system and possible equipment damage.

NOTICE

This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with this
instruction manual, may cause interference to radio communications. Operation of this equipment in a residential area is likely to
cause interference in which case the user will be required to correct the interference at their expense. McQuay International
disclaims any liability resulting from any interference or for the correction thereof.

Equipment Location

WME chillers are intended only for installation in an indoor or weather protected area consistent with the NEMA 1
rating on the chiller, controls, and electrical panels. Equipment room temperature for operating and standby conditions
is 40°F to 122°F (4.4°C to 50°C).

OMM 1034-2

3

Optimum Water Temperatures and Flow

A key to improving energy efficiency for any chiller is minimizing the compressor pressure lift. Reducing the lift
reduces the compressor work and its energy consumption per unit of output. The chiller typically consumes more energy
than any other component in the chiller system. Therefore, the optimum plant design must take into account all of the
interactions between chiller, pumps, and tower.

Higher Leaving Chilled Water Temperatures

Warmer leaving chilled water temperatures will raise the compressor's suction pressure and decrease the lift, improving
efficiency. Using 45°F (7°C) leaving water instead of 42°F (5.5°C) will significantly reduce chiller energy consumption.

Evaporator Temperature Drop

The industry standard has been a 10°F (5.5°C) temperature drop in the evaporator. Increasing the drop to 12°F or 14°F
(6.6°C or 7.7°C) will improve the evaporator heat transfer, raise the suction pressure, and improve chiller efficiency.
Chilled water pump energy will also be reduced.

Reduced Evaporator Fluid Flow

Several popular chiller plant control practices including Variable Primary Flow systems advocate reducing the
evaporator fluid flow rate as the chiller capacity is reduced. This practice can significantly reduce the evaporator
pumping power while having little effect on chiller energy consumption. The Magnitude chiller can operate effectively
in variable evaporator flow systems as long as the minimum and maximum tube velocities are taken into consideration
when selecting the chiller. See section on Variable Fluid Flow Rates on page 7.

Condenser Entering Water Temperature

As a general rule, a 1°F (0.5°C) drop in condenser entering water temperature will reduce chiller energy consumption
by two percent. Cooler water lowers the condensing pressure and reduces compressor work. One or two degrees can
make a noticeable difference. The incremental cost of a larger tower can be small and provide a good return on
investment.

Condenser Water Temperature Rise

The industry standard of 3 gpm/ton or about a 9.5°F (5.3°C) delta-T seems to work well for most applications.

Reduced Condenser Fluid Flow

Several popular chiller plant control practices also advocate reducing the condenser fluid flow rate as the chiller load is
reduced. This practice can significantly reduce the condenser pumping power, but it may also have the unintended
consequence of significantly increasing compressor power since the leaving condenser water temperature is directly
related to compressor lift and power. The higher compressor power will typically be larger than the condenser pumping
power reduction and will result in a net increase in chiller plant energy consumption. Therefore, before this strategy is
applied for energy saving purposes it should be extensively modeled or used in an adaptive chiller plant control system
which will take into account all of the interdependent variables affecting chiller plant energy. If it is decided to use
variable condenser fluid flow, the Magnitude chiller can operate effectively as long as the minimum and maximum tube
velocities are taken into consideration when selecting the chiller.

Free-Cooling Pressure Inversion

Pressure inversion can happen in the chiller when the building system uses free cooling. The chiller had been in the
OFF state with no water flowing so the pressure inside was relatively high and corresponds to the water temperatures
inside the heat exchangers. When the condenser pumps starts with cold water from the free-cooling system, the sudden
drop in condenser temperature creates an inverted pressure situation. The refrigerant inside the heat exchangers flows to
equalize the pressure. During this process, there can be enough pressure difference to cause reverse flow and impeller
rotation for a short time. As long as power to the chiller is on, the WME software recognizes this condition and will
levitate the bearings until the pressure equalizes. Once the pressure equalizes, the chiller will operate as normal.

4 OMM 1034-2

30

35

40

45

50

55

60

65

0 10 20 30 40 50 60 70 80 90 100

Percent Load

ECWT (°F)

46°F LChWT
44°F LChWT
42°F LChWT

Chilled Water Temperature

The maximum temperature of water entering the chiller on standby must not exceed 105°F (46.1°C). Maximum
temperature entering on start-up must not exceed 90°F (32°C). Minimum chilled water leaving temperature without
antifreeze is approximately 38°F (3.3°C).

Piping

Piping must be adequately supported to remove weight and strain on the chiller's fittings and connections. Be sure
piping is adequately insulated for job conditions. Install a cleanable 20-mesh water strainer upstream of the evaporator
and condenser. Install enough shutoff valves to permit draining water from the evaporator or condenser without draining
the complete system.

Condenser Water Temperature

When the ambient wet bulb temperature is lower than design, the entering condenser water temperature of Magnitude
model WME chillers can be lowered to improve chiller performance.

Chillers can start with entering condenser water temperatures as low as 40°F (4.4°C). For short periods of time during
startup, the entering condenser water temperature can even be lower than the leaving chilled water temperature.

Magnitude model WME chillers are equipped with electronic expansion valves (EXV) and will run with entering
condenser water temperatures as low as shown in Figure 1 or as calculated from the following equation on which the
curves are based:

Min. ECWT = 5.25+(LWT)-0.75*DT

*(PLD/100)+14 *(PLD/100)2

FL

Where:

ECWT = Entering condenser water temperature
LWT = Leaving chilled water temperature
DTFL = Chilled Water Delta-T at full load
PLD = The percent chiller load point to be checked

Figure 1: Model WME Minimum Entering Condenser Water Temperature (EXV) (10°F Range at Full Load)

For example; at 44°F LWT, 10°F Delta-T at full load, and 50% full load operation, the entering condenser water
temperature could be as low as 49°F. This provides excellent operation with water-side economizer systems.

OMM 1034-2

5

Depending on local climatic conditions, using the lowest possible entering condenser water temperature may be more
costly in total system power consumed than the expected savings in chiller power would suggest, due to the excessive
fan power required.

In this scenario, cooling tower fans would continue to operate at 100% capacity at low wet bulb temperatures. The
trade-off between better chiller efficiency and fan power should be analyzed for best overall system efficiency.
McQuay’ s Energy Analyzer™ program can optimize the chiller/tower operation for specific buildings in specific
locales.

Even with tower fan control, some form of water flow control, such as tower bypass, is recommended.

Figure 2 and Figure 3 illustrate two temperature-actuated tower bypass arrangements. The “Cold Weather” scheme,
Figure 3: Tower Bypass: Cold Weather Operation (Bypass Indoors), provides better startup under cold ambient air

temperature conditions. The bypass valve and piping are indoors and thus warmer, allowing for warmer water to be
immediately available to the condenser. The check valve may be required to prevent air at the pump inlet.

Figure 2: Tower Bypass: Mild Weather Operation

Figure 3: Tower Bypass: Cold Weather Operation (Bypass Indoors)

Condenser water temperature control

The standard MicroTech controller is capable of three stages of tower fan control plus an analog control of either a
three-way tower-bypass valve or variable speed tower-fan motor. Stages are controlled from condenser-water
temperature. The three-way valve can be controlled to a different water temperature or track the current tower stage.
This allows optimum chilled water plant performance based upon specific job requirements.

Pumps

The condenser water pump(s) must be cycled off when the last chiller of the system cycles off. This will keep cold
condenser water from migrating refrigerant to the condenser. Cold liquid refrigerant in the condenser can make start up
difficult. In addition, turning off the condenser water pump(s) when the chillers are not operating will conserve energy.

6 OMM 1034-2

Include thermometers and pressure gauges at the chiller inlet and outlet connections and install air vents at the high
points of piping. Where noise and vibration are critical and the unit is mounted on spring isolators, flexible piping and
conduit connections are necessary.

Variable Fluid Flow Rate s and Tube Velocities

Many chiller system control and energy optimization strategies require significant changes in evaporator and condenser
water flow rates. The Magnitude chiller line is particularly well suited to take full advantage of these energy saving
opportunities provided that the maximum and minimum fluid flow rates are taken into consideration for a specific
application. The sales engineer has the flexibility to use different combinations of shell size, number of tubes, and pass
arrangements to select the optimum chiller for each specific application.

Both excessively high and excessively low fluid flow rates should be avoided. Excessively high fluid flow rates and
correspondingly high tube velocities will result in high fluid pressure drops, high pumping power, and potentially tube
corrosion and/or tube corrosion damage. Excessively low fluid flow rates and correspondingly low velocities should
also be avoided as they will result in poor heat transfer, high compressor power, sedimentation and tube fouling.
Excessively high and low tube velocities can be particularly problematic and damaging in open loop systems.

Rates of Fluid Flow Change

If it is decided to vary the evaporator water flow rate the rate of change should not exceed 50% per minute and should
not exceed the minimum or maximum velocity limits as determined by the Daikin McQuay chiller software program.

Vibration Mounting

The Magnitude chillers are almost vibration-free. Consequently, floor mounted spring isolators are not usually required.
Rubber mounting pads are shipped with each unit. It is wise to continue to use piping flexible connectors to reduce
sound transmitted into the pipe and to allow for expansion and contraction.

System Water Volume

All chilled water systems need adequate time to recognize a load change, respond to that load change and stabilize,
without undesirable short cycling of the compressors or loss of control. In air conditioning systems, the potential for
short cycling usually exists when the building load falls below the minimum chiller plant capacity or on close-coupled
systems with very small water volumes.

Some of the things the designer should consider when looking at water volume are the minimum cooling load, the
minimum chiller plant capacity during the low load period and the desired cycle time for the compressors.

Assuming that there are no sudden load changes and that the chiller plant has reasonable turndown, a rule of thumb of
“gallons of water volume equal to two to three times the chilled water gpm flow rate” is often used.

A properly designed storage tank should be added if the system components do not provide sufficient water volume.

Multi-chiller

Up to eight WME chillers are capable of being interconnected and operating in a multi chiller mode using their internal
control network. Please contact McQuay Service for installation of the correct software for multi-chiller operation.

System Analysis

Although we recommend analyzing the entire system, it is generally effective to place the chiller in the most efficient
mode because it is a large energy consumer.

The McQuay Energy Analyzer program is an excellent tool to investigate the entire system efficiency, quickly and
accurately. It is especially good at comparing different system types and operating parameters. Contact your local
Daikin McQuay sales office for assistance on your particular application.

OMM 1034-2

7

Features of the Control Panel

• Control of leaving chilled water within a ±0.5°F (±0.3°C) tolerance. Systems with a large water volume and

relatively slow load changes can do better.

• Readout of the following temperature and pressure readings:

• Entering and leaving chilled water temperature

• Entering and leaving condenser water temperature

• Saturated evaporator refrigerant temperature and pressure

• Saturated condenser temperature and pressure

• Suction line, liquid line and discharge line temperatures - calculated superheat for discharge and suction lines –

calculated sub-cooling for liquid line

• Automatic control of primary and standby evaporator and condenser pumps.

• Control up to 3 stages of cooling tower fans plus modulating bypass valve and/or tower fan VFD.

• The controller will store and display key historic operating data for recall in a graphic format on the screen. Data

can also be exported for archival purposes via a USB port.

• Security password protection against unauthorized changing of setpoints and other control parameters.

• Warning and fault diagnostics to inform operators of warning and fault conditions in plain language. Al1 warnings,

problems and faults are time and date stamped so there is no guessing of when the fault condition occurred. In
addition, the operating conditions that existed just prior to shutdown can be recalled to aid in isolating the cause of
the problem.

• Eight latest faults are displayed on the touch screen. Data can be exported for archival purposes via a USB Drive.

• Soft loading feature reduces electrical consumption and peak demand charges during the cooling loop pull-down.

• Adjustable load pull-down rate reduces under-shoot during initial loop pull-down.

• Remote input signals for chilled water reset, demand limiting, unit enable.

• Manual (Service) control mode allows the service technician to command the unit to different operating states.

Useful for system checkout.

• Optional Building Automation System communication capability via LONMARK, Modbus or BACnet

standard protocols for BAS manufacturers.

• Test mode for troubleshooting controller hardware.

• Pressure transducers for direct reading of system pressures. Preemptive control of high motor amps, high motor

temperature, low evaporator pressure conditions and high discharge temperature takes corrective action prior to a
fault trip.

8 OMM 1034-2

Frequency

Drive

BAS

Ethernet/RS232/RS485/LON

Ethernet

Chiller #2

wall

Ethernet

(Local Network)

Ethernet

(Local Network)

General Description

General Description

The centrifugal MicroTech-E control system consists of microprocessor-based controllers that provide all monitoring
and control functions required for the controlled, efficient operation of the chiller. The system consists of the following
components:

• Operator Interface Touch Screen (OITS), one per unit-provides unit information and is the primary user interface

for all system data and setpoint information.

• Unit Controller, one per chiller, controls unit functions and communicates with all other controllers. It is located

in a panel adjacent to the OITS.

• Compressor Controller for the compressor controls compressor functions such as loading and unloading and

collects I/O points near the compressor, located in the compressor.

• The operator can monitor all operating conditions by using the unit-mounted OITS. In addition to providing all

normal operating controls, the MicroTech-E control system monitors equipment protection devices on the unit
and will take corrective action if the chiller is operating outside of it’s normal design conditions. If a fault
condition develops, the controller will shut the compressor or entire unit down and activate an alarm output.
Important operating conditions at the time an alarm condition occurs are retained in the controller’s history log
to aid in troubleshooting and fault analysis.

• The system is protected by a password scheme that only allows access by authorized personnel. The operator

must enter the password into the touch screen before any setpoints can be altered.

Control Architecture

Figure 4, Major Control Components

(BACnet,

Modbus,

ONTALK)

L

Remote user

interface

Chiller #1

Color

Monitor /

Touchsreen

Local User Interface

VGA

RS232

12VDC

BAS
Card

Chiller

Controller

Fire-

Variable

Compressor

Controller

OMM 1034-2

9

External Control Wiring

External Control Terminal
USB Ports (2)

Normal Shutdown

Immediate

Ethernet Port

Component Description

Operator Interface Touch Screen

The operator interface touch screen (OITS) is the primary device by which commands and entries into the control
system are made (a laptop computer can also be used). It also displays all controller data and information on a series of
graphic screens.

The control panel contains a USB port that can be used for loading information to and from the control system
including download of trend log data and uploading software upgrades.

The OITS panel is mounted on a moveable arm to allow placement in a convenient position for the operator. There is a
screen-saver programmed into the system. The screen is reactivated by touching it anywhere.

Unit Controller

There is one unit controller mounted on the chiller which is the primary interface to the user and for field I/O
connections.

Unit and compressor on/off switches are mounted in the unit controller panel located adjacent to the OITS panel. They
are designated 1 for on and O for off. The compressor on/off switch should only be used when an immediate stop is
required since the normal shut down sequence is bypassed.

There is a unit enable switch located on the left outside of the panel that causes a controlled shutdown of the
compressor.

The unit controller's primary function is processing data relating to the entire chiller unit operation, as compared to data
relating to the compressor operation. The unit controller processes information and sends data to other controllers and
devices and relays information to the OITS for graphic display.

The following functions operate in the unit controller:

• User interface

• BAS interface

• Field I/O; pumps, alarm contact, remote start/stop, tower control

• Chiller I/O; water temperatures, EXV control, condenser pressure

• Data trending

• Chiller alarm handling

• Alarm display

Figure 5, Unit Control Panel

Switch

Entry (4)

Strip

Shutdown Switch

External Normal

Shutdown Switch

.

10 OMM 1034-2

Motor/Compressor Controller

The following functions operate in the compressor controller:

• Bearing Control

• Suction/Discharge Temperature and Pressure

• IGV control

• Speed Control

• RPM sensing

• Load Control

• Compressor Alarm Handling

• Motor Tem perature control

• Compressor staging and load balancing on multi-chiller installations

VFD Controller

The following functions operate in the VFD controller:

• Controls motor according to speed setpoint

• VFD heat sink temp control (solenoids)

• High Pressure switch monitor

• Ground fault protection (optional)

• Over-current protection

• VFD alarm handling

• Control power distribution

• Regenerative power in case of power loss

• Short circuit protection

VFD Description:

The VFD has several main components or sections:

1) Input power section:

• Circuit breaker ( standard)

• Ground fault detection ( optional)

• Power meter ( optional)

2) Control power section:

• 120VAC

• 24VDC

• 300VDC (intermediate power supply)

3) Power conditioning

• Main power autotransformer – used for low harmonics version or where buck/boost is required.

- ( 460V low harmonics option, 575V, 380V )

• EMI filters (optional), use where low-level EM emission from the VFD panel are undesirable.

• Line Reactors - standard

4) Heat sink assemblies: ( main power control assembly)

• M2 version – 1 heat sink assembly

• M3 version – 2 heat sink assemblies

The main purpose of the M3 version with the transformer is to provide lower harmonics than the standard M2 system.

OMM 1034-2

11

Description

NTC

(Note 1)

NTC

(Note 1)

NTC

(Note 1)

(Note 1)

(Note 1)

NTC

(Note 1)

NTC

(Note 1)

Sealed Gage

Transducer

0.3 to 4.5
VDC

-20.3 to 410

psi

Key VFD Control Signals

VFD enable from Compressor to VFD (relay contact)
Speed reference (command speed) from compressor to VFD (4-20 mA analog)
Compressor RPM sensor output to VFD (digital pulse)
VFD amps to Compressor (Ethernet)

The remaining chiller data, setpoints, and control signals travel between the chiller, compressor, and VFD using an
Ethernet network.

Inputs and Outputs

Unit Controller

Table 1, Unit Controller, Analog Inputs

#

Entering Evaporator Water

1

Temperature
Leaving Evaporator Water

2

Temperature
Entering Condenser Water

3

Temperature
Leaving Condenser Water

4

Temperature
Entering Heat Recovery Water

5

Temperature

Wiring Source Signal Range

Chiller

Chiller

Chiller

Chiller

Chiller

Thermistor

Thermistor

Thermistor

NTC

Thermistor

NTC

Thermistor

10k@25°C -40 to 125°C

10k@25°C -40 to 125°C

10k@25°C -40 to 125°C

10k@25°C -40 to 125°C

10k@25°C -40 to 125°C

Leaving Heat Recovery Water

6

Temperature

7 Liquid Line Refrigerant Temperature Chiller

Condenser Refrigerant Pressure Chiller

8

9 Evaporator W ater Flow Rate Field

10 Condenser Water Flow Rate Field

Reset of Leaving Water

11

Temperature

12 Demand Limit Field BAS

13 Refrigerant Leak Sensor Field Leak Sensor

14 Ambient Temperature Field

Note 1: Thermistor curves according to standard McQuay thermistor probe specification.

Chiller

Field BAS

Thermistor

Thermistor

Water Flow

Sensor

Water Flow

Sensor

NTC

Thermistor

10k@25°C -40 to 125°C

10k@25°C -40 to 125°C

4 to 20 mA

Current

4 to 20 mA

Current

4-20 mA

Current

4-20 mA

Current

4 to 20 mA

Current

10k@25°C -40 to 212°F

0 to 10,000

gpm

0 to 10,000

gpm

0 to100%

0-100 %RLA

0 to 100 ppm

12 OMM 1034-2

OPEN/CLOSED

1

Front Panel “Stop/Auto” Switch

Chiller

Isolated Switch Contacts

Stop / Auto

Isolated Switch or Relay

Contacts

Contacts

Alternate Mode

Chiller & Field

(in series)

Isolated Flow Switch

Contacts

(in series)

Contacts

6

Compressor Manual OFF Switch

Chiller

Isolated Switch Contact

Stop/Auto

#

Description

Load

Rating

1

Alarm

Indicator Light

240 VAC

2

Evaporator Water Pump #1

Pump Contactor

240 VAC

3

Evaporator Water Pump #2

Pump Contactor

240 VAC

4

Condenser Water P ump #1

Pump Contactor

240 VAC

5

Condenser Water P ump #2

Pump Contactor

240 VAC

6

Cooling Tower Fan #1

Fan Contactor

240 VAC

7

Cooling Tower Fan #2

Fan Contactor

240 VAC

8

Cooling Tower Fan #3

Fan Contactor

240 VAC

#

Description

Output Signal

Range

1

Cooling Tow er Bypass Valve Position

0 to 10 VDC

0 to 100% Open

2

Cooling Tower VFD Speed

0 to 10 VDC

0 to 100%

Description

Motor

Table 2, Unit Controller, Digital Inputs

# Description Wiring Signal Source

States –

Remote Start/Stop Field

2

Mode Switch Field

3

Evaporator Water Flow Switch

4

Condenser Water Flow Switch

5

Chiller & Field

Table 3, Unit Controller, Digital Outputs

Table 4, Unit Controller, Analog Outputs

Isolated Switch or Relay

Isolated Flow Switch

Stop / Auto

Normal /

No Flow / Flow

No Flow / Flow

Table 5, Stepper Motor Outputs

The following output is provided for stepper motor driven actuators.

#
1

Electronic Expansion Valve 24VDC, 10 VA max

OMM 1034-2

13

#

Description

Source

Signal

Range

1

Compressor Suction Temperature

NTC Thermistor

10k@25°C

-40 to 125°C

2

Compressor Discharge Temperature

NTC Thermistor

10k@25°C

-40 to 125°C

3

Suction Refrigerant Pressure

Sealed Gage Transducer

0.3 to 4.5 VDC

-6.6 to 132 psi

4

Discharge Refrigerant Pressure

Sealed Gage Transducer

0.3 to 4.5 VDC

-20.3 to 410 psi

5

Rotor Pump Temperature

NTC Thermistor

10k@25°C

-40 to 125°C

6

Inlet Guide Van e Position

Rotary Transducer

0.5 to 4.5 VDC

Closed to Open

7

Motor Winding Temperature 1

NTC Thermistor

10k@25°C

-40 to 150°C

8

Motor Winding Temperature 2

NTC Thermistor

10k@25°C

-40 to 150°C

9

Motor Winding Temperature 3

NTC Thermistor

10k@25°C

-40 to 150°C

10

Motor Case Tem peratu re

11

Motor Gap Temperature

NTC Thermistor

10k@25°C

-40 to 125°C

#

Description

Load

Output OFF

Output ON

1

VFD Enable

VFD

Compressor OFF

Compressor ON

2

Liquid Injection

Solenoid (24 VDC, 20 VA max)

No Injection

Injection

3

Stator Cooling

Solenoid (24 VDC, 20 VA max)

Cooling OFF

Cooling ON

Cooling)

Counter

Clockwise

1

Inlet Guide Vane Position

24VDC, 100 VA max

Open Vanes

Close Vanes

Compressor Controller

Table 6, Compressor Controller, Analog Inputs

Table 7, Compressor Controller, Digital Inputs

None

Table 8, Compressor Controller, Analog Outputs

None

Table 9, Compressor Controller, Digital Outputs

4

Spare (Motor

Solenoid (24 VDC, 20 VA max) Cooling OFF Cooling ON

Table 10, Stepper Motor Outputs

The following output is provided for stepper motor driven actuators.

# Description Motor Clockwise

14 OMM 1034-2

CAUTION

or

blown fuses.

CAUTION

ust be only be perfor med by technicians tra ined and e xperi enced i n working on

them.

Optional Harmonic Filter

The optional harmonic filter is a device that reduces harmonics. It may be factory-mounted in the chiller power panel or remotely mounted in the field.

Operation

The harmonic filter is a passive device and there is no operator action required.

Cleaning

Excessive accumulations of dirt on the reactor windings or insulators and capacitor terminals should be removed to
permit free circulation of air and to guard against the possibility of insulation breakdown. Particular attention should be
given to cleaning the top and bottom ends of the winding assemblies and to cleaning out ventilating ducts. Windings
should be lightly cleaned by the use of a vacuum cleaner. If necessary a blower or compressed air may be used but
pressure should not exceed 25 psi. Lead supports, tap changers and terminal boards, bushings, and other major
insulating surfaces should be brushed or wiped with a dry cloth. The use of liquid cleaners is not recommended due to
deteriorating effects on most insulating materials.

Periodic Inspection and Maintenance

The filter has no moving or active parts and therefore requires only minimal periodic maintenance when installed in a
clean and well ventilated environment. Annual maintenance is recommended. This should include:

1. Visual inspection for evidence of loose connections, dirt, moisture, rusting, corrosion, and deterioration of the

insulation, varnish or paint. Observations should be made for signs of overheating and overvoltage creeping.
Corrective measures should be taken as necessary.

2. For early detection of any developing hotspots, an infrared scan can be performed while the unit is operating under

its heaviest load condition.

3. The unit capacitors are equipped with an internal ‘Tear-Off’ fuse pressure interrupter to prevent explosive failure.

At the end of its service life, pressure within a capacitor will build due to the release of gases as its dielectrics
breakdown. The covers on the cans are designed to expand or bulge and Tear-Off the internal fuse as this pressure
builds. Capacitors should be inspected regularly and replaced when found to have an expanded cover.

Ensure that power to the unit has been turned off and safely isolated before replacing failed capacitors

4. Most units are also equipped with capacitor fuses. Capacitor fuses are intended to provide additional protection

against overloading of the capacitors. A blown fuse can be detected by checking for illumination of the blown fuse
indicator when this option has been purchased or by measuring the voltage across the fuse terminals while
energized. If voltage is not near zero or the blown fuse indicator is on, the fuse should be replaced.

5. Measuring the current in each of the three phases of the capacitor circuit can be a quick and easy method of

determining the condition of the capacitors. The capacitors can be assumed to be in good operating condition when
all three phases carry approximately the same amount of load current. Measurements should be taken at the input to
the capacitor distribution block and can be done at any loading condition. Phase currents that are imbalanced by
more than 10%, indicate a capacitor failure or blown fuse. When the filter capacitor bank has been connected in a
wye configuration (ie. Two jumpers create a common point on each set of three capacitors), locating the problem
capacitor(s) can be achieved by measuring the voltage between the common neutral point of each set to ground. If
the voltage difference is greater than 10 volts, at least one of the capacitors in that set has failed or has a blown fuse.
Testing should be conducted annually or whenever the unit seems to be operating in an abnormal manner. The unit
is capable of continued operation with some failed capacitors or blown capacitor fuses. Harmonic mitigation
performance will be sacrificed however, so it is recommended that all failed capacitors or blown capacitor fuses be
replaced as soon as is practically possible after detection.

Service work on this device m

OMM 1034-2

15

Field Control Wiring Diagram

Figure 6, Field Wiring Diagram

NOTE: Terminals shown are on the right side of the Unit I/O Board located in the control panel.

16 OMM 1034-2

Operator Interface Touch Screen (OITS)

Navigation

The home screen shown in VIEW screen is usually left on (there is a screen-saver built in that is reactivated by
touching the screen anywhere). This VIEW screen contains the STOP and AUTO buttons used to start and stop the unit
when in user control. Other groups of screens can be accessed from the Home screen by pressing one of the buttons on
the bottom of the screen; TREND, VIEW, SET , ALARM.

• TREND will graph the recent data for several system variables: evaporator water temperatures, condenser water

temperatures, evaporator pressure, condenser pressure, % RLA, % RPM, % Vanes.

• ALARM will display recent and active alarms.

• VIEW will go to the next View screen and other sub-View screens used to look in detail at settings and the

operation of the chiller. Pressing View from any other screen will return to the previously selected View screen.
View screens are used for looking at unit status and conditions.

• SET will go to a series of screens used to set or view setpoints.

NOTE: The data shown on screens in this section do not necessarily reflect actual operating conditions.

Figure 7, Home View Screen

Home View Screen

The Home View Screen shows the basic condition of the chiller.

Information

• State of compressor and pumps; a green light indicates on. black indicates off.

• Active chilled water (LWT) setpoint

• Entering and leaving chilled water temperatures

• Entering and leaving condenser water temperatures

OMM 1034-2 17

• Percent motor amps (approximates percent load)

• UNIT STATUS consists of unit MODE, followed by STATE, followed by the SOURCE that is the device or

signal that created the STATE. The possible messages are in the following table:

Table 11, UNIT STATUS Combinations

MODE STATE SOURCE

COOL OFF Manual Switch

TEST SHUTDOW N ( See Note) Remot e Switch

AUTO User
BAS Network

Note: Shutdown is the chiller state when in the process of shutting down.
The Home View Screen-Detail gives additional information on the refrigerant pressures and temperatures, compressor

speed and other system data. When first booted up, this screen will only show the left side. As soon as one of the
details, such as STATE is selected, and from then on, the screen will show information appearing on the right side.

Figure 8, Home View Screen-Detail

Pressing the STATE button will bring up a display of the compressor state superimposed on the View Home Screen­Detail as shown in Figure 8.

Pressing the I/O button will bring up a display of the compressor inputs and output status (I/O) superimposed on the
View Home Screen-Detail as shown in Figure 9. These I/Os are to and from the compressor controller.

18 OMM 1034-2

Figure 9, Compressor I/O Screen

Digital Outputs

: a green light to the left of a condition indicates it is active. Liquid injection is a user option controlled

by a setpoint.
Analog Inputs: data from sensors connected to the compressor.
Analog Output: Compressor speed output
Stepper Outputs: compressor stepper outputs for inlet guide position and rotor cooling

OMM 1034-2 19

Pressing the UNIT I/O button, located in the lower-left corner of the screen, displays the current unit inputs and
outputs superimposed on the View Home Screen-Detail as shown in

Figure 10. These I/Os are to and from the unit

controller.

Figure 10, Unit Input/Output (I/O)

Digital Inputs: inputs to the unit controller that determine if the compressor can start.
Digital Outputs: outputs to start the evaporator and condenser pumps and tower fans or indicate an alarm condition

such as no flow.
Analog Outputs: analog outputs to set the tower bypass valve and/or the tower fan VFD to the correct position or

speed.
Analog Inputs: inputs usually from a BAS to control LWT reset and demand limiting for the compressor power input.
Pressing the EVAP or COND button, located on the vessels, will give detailed information on the evaporator or

condenser pressures and temperatures.

20 OMM 1034-2

Figure 11, Evaporator Screen

Figure 12, Condenser Screen

OMM 1034-2 21

Pressing the Power button, located on the left side of the screen, will access the screen giving power data. Individual
line current and voltage values and power factor are only available with the optional Input Power Meter.

Figure 13, Power Screen

22 OMM 1034-2

Setpoint

Setpoint

Current
Buttons to Access Other
Keypad

Current Unit &

SET Screens

The set screens on the Interface Panel are used to input the many setpoints associated with equipment of this type.
MicroTech-E provides an extremely simple method for accomplishing this. Appropriate setpoints are factory set and
checked by McQuay Factory Service or a Factory Authorized Service Company during commissioning. However,
adjustments and changes are often required to meet job conditions. Certain settings involving pumps and tower
operation are always field set.

Pressing the SET button from any other screen accesses the SET screen. Pressing the SET button while on a SET
screen will access the SERVICE screen.

The various setpoint groups are in a column on the right side of the screen. Each button contains a number of setpoints
grouped together by similar content. For example, The WATER contains various setpoints relating to water
temperatures.

NOTE: Some setpoints that do not apply to a particular application may still be listed on the screen. They will be
inactive and can be ignored.

The numbered buttons in the second from right column are pressed to select a particular setpoint. The selected setpoint
will appear in green on the screen and a description of it (with the range of available settings) will appear in the upper
left-hand box.

Figure 14, Typical Setpoint Screen

Compressor Status

Setpoint

Values

Access

Numbers

Groups

Setpoint Description and
Range of Values

OMM 1034-2 23

Menus

Procedure for Changing a Setpoint

A list of setpoints, their default value, their available setting range, and password authority are shown on the page
relating to the particular setpoint screen beginning on page 25.

Press the applicable Setpoint Group Button. A complete explanation of setpoint content of each group follows this
section.

1) Select the desired setpoint by pressing the numbered button.

2) Press the CHANGE button indicating that you wish to change a setpoint value. The KEYBOARD screen will

be turned on automatically for entering the password.

3) O= Operator password : default = 100

4) T = Technician level password is reserved for authorized technicians

5) Press the appropriate numbers in the numeric keyboard to enter the password. There is a small delay between

pressing the keypad and recording the entry. Be sure that an asterisk appears in the window before pressing the
next number. Press ENTER to return to the SETPOINT screen. The password will remain open for 15 minute
after initiation and does not need to be re-entered during this period.

6) Press CHANGE again

7) The numeric keypad and action buttons in the lower left-hand corner of the screen will be activated. Setpoints

with numeric values can be changed in two ways:

• Select the desired value by pressing the numbered buttons. Press ENTER to enter the value or CANCEL to

cancel the transaction.

• Press the UP or DOWN button to increase or decrease the value displayed. Press ENTER to enter the value or

CANCEL to cancel the transaction.

Some setpoints are text rather than numeric values. For example, LWT Reset Type can be "None" or "4-20 ma". The
selection can be made by toggling between choices using the UP or Down button. If dashed lines appear in the setpoint
window, it indicates that you have toggled too far and need to reverse direction. Press ENTER to enter the choice or
CANCEL to cancel the transaction.

Once CHANGE is selected, the CANCEL or ENTER buttons must be pressed before another setpoint can be selected.
Additional setpoints can be changed by selecting another setpoint on the screen or by selecting an entirely new group
of setpoints.

Explanation of Setpoints

Each of the setpoint groups of screens are detailed in the following section. The groups are:
WATER, UNIT, STAGING, POWER, TOWER, VALVE, ALARMS, BAS
In some cases, pressing the button again may display a second page of setpoints in the same group.
Pressing SET from any SET screen accesses the SERVICE screen. In other words, it is the second "SET" screen. While

containing information and activity buttons for the service technician, it also has valuable information for the operator.
The software version numbers shown in the lower left corner are the controllers' software identification. These

numbers may be required by Daikin McQuay to answer questions about unit operation or to assist in possible future
upgrades of software.

24 OMM 1034-2

Setpoint Screens

Figure 15, BAS Setpoint Screen #1

Figure 16, BAS Setpoint Screen #2

Screen details on the following page.

OMM 1034-2 25

.

Time

must re-register with the B BMD.

BACnet IP -

(XXX.XXX.XXX.XXX)

The Internet Protocol (IP ) addres s for the

(XXX.XXX.XXX.XXX)

47808

mal).

(XXX.XXX.XXX.XXX)

0 to 255

0 to 255

NO: Do not use Daylight

Savings Time.

sent when there is no acknowledgment.

3000

ds

The retry timeout interval (msec) for Application

require acknowledgment.

BACnet (all) -

Description

The desired BACnet descript i on

of this particular chi l l er

BACnet (all) -

Object Name

Device Instance

Instance number.

ENGLISH: Use English

liter/sec)

BAS Network Protocol

BACnet MS/TP: RS485

Table 12, BAS Screen #1 Setpoints

Description

BACnet IP -

Foreign Device

No

Default Range Password Comments

15 0 (0) to 65535 Seconds O

The Time-to-Live, in seconds, withi n

which the Chiller (a Foreign Device)

BBMP IP

Address

BACnet IP -

Default Gateway

BACnet IP UDP

Port

BAC net IP

Subnet Mask

BACnet IP -

Network Addr

BACnet (all) -

UTC Offset

BACnet (all) -

Daylight Savings

Time

BACnet (all) -

APDU Retries

BACnet (all) -

APDU Tiimeout

0.0.0.0 =

14

"None

13 None

decimal

12

(BAC0

hexadeci

255.255.2

11

10 172.15.5.8

9 0 -780 to +780 minutes O

8 None

7 3 0 to 10 O

6

55.0

millisecon

where each XXX can be

0 to 255

where each XXX can be

0 to 255

0 to 65535 decimal O

where each XXX can bo

(XXX.XXX.XXX.XXX)

where each XXX can bo

Savings Time.

YES: Use Daylight

0 to 60,000 millisec onds O

O

O

O

O

O ---

BACnet Broadcast Management Device (BBMD)

to which the chiller is registered.

The Internet Protocol (IP ) addres s

of the BACnet IP router.

The User Datagram Protocol (UDP) port number

to use on the IP network.

Subnet Mask for the

communicati on module.

The four-octet (32-bit) Internet Protocol (IP)

address for the communications module.

Sets the local time zone by Specifying the

zone's offset from Uni vers al T i me Coordinated

(UTC)

in minutes.Exampl e: US Central Standard

Time (CST) is -360.)

The maximum number of times an Application

Protocol Data Unit (APDU) t ransmission shall be

Protocol Data Unit (APDU) trans missions that

BACnet (all) -

BACnet (all) -

English / Metric

BAS Network

Protocol

5 None 31characters maximum . O

4 31 characters maximum. O The unique BACnet Object Nam e

3 3000 0 to 4194302 O

2 English

1 None

units. (Deg F, PSI, GPM)

METRIC: Use Metric

units. (Deg C, kPa,

NONE: No BAS network

MODBUS: RTU - RS485

LON: LONtalk - FTT-10A

BACnet IP: IP - Ethernet

BACnet Ethernet:

Ethernet

O ---

O ---

The unique BACnet Device

26 OMM 1034-2

Description

No.

Default

Range

Password

Comments

Rate

19200

RS485 network.

Network Address

RS485 network.

BACnet MS/TP -

9600, 19200, 38400,

Sets the communications baudrate to use on t he

Maximum number of Information Frames that c an

BACnet MS/TP -

Maximum number of mas ter controllers currently

BACnet MS/TP -

MAC Address

Unique MAC Address of the com munication

module.

XX-XX-XX-XX-XX-XX

Table 13, BAS Screen #2 Setpoints

MODBUS - Baud

MODBUS -

MODBUS

Eng/Metric

Baud Rate

BACnet MS/TP

Max Info Frames

Max Masters

BACnet Ethernet -

MAC Address

8 9600

7 1 1 to 247 O

6 English English or Metric O

5 38400

4 5 1 to(5 O

3 127 1 to 127 O

2 1 0 to 127 O

1

Figure 17, Alarms Screen

1200, 2400, 4800, 9600,

76800

Each XX can be 00 through

FF hexadecimal

O

O

O

Sets the communications baud rate to use on t he

Sets the address to use on the

ENGLISH: Use English uni ts. (Deg F, PSI, GPM)

METRIC: Use Metric units. (Deg C, k Pa, liter/sec)

RS485 network.

be sent before the communication module m ust

pass the token.

on the network.

Unique MAC Address of the com munication

module.

OMM 1034-2 27

word

Sets the value of condenser saturated

Sets the value of evaporator saturat ed
is forced ON.

considered ON.

Sets the Surge Temp (ST ) slope value above

Deactivated when ST drops below SP7.

High Discharge Temp­Stop

Sets the discharge temperature above which the
compressor is shut down.

Sets the discharge temperature above which a
occurs.

Sets the evaporator pressure value below which

Low Evap Pressure-

Sets the evaporator pressure value below which

Sets the evaporator pressure value below which
inhibited.

Table 14, ALARM Setpoints

Description No. Default Range

Pass-

Comments

Condenser Freeze
Protect

Evaporator Freeze
Protect

Motor Current Threshold 9 5% 3% to 99% T

Surge Slope Limit 8 20 1 – 99 deg F/min. T

Surge Temperature Limit 7 6 2 – 25 deg F T

High Discharge Temp­Load

High Condenser Pressure 4 140 psi 120 to 240 psi T
Low Evap Pressure, Stop 3 26 psi 10 to 45 psi O

Unload
Low Evap Pressure-

Inhibit

11

34.0 °F -9.0 to 45.0 °F

10

34.0 °F -9.0 to 45.0 °F

6

190 °F 120 to 240 °F

5

190 °F 120 to 240 °F

2 31 psi 20 to 45 psi O

1 35 psi 20 to 45 psi O

O

O

T

T

temperature below which the condenser
pump is forced ON.

temperature below which the evaporator pump
When %RLA is bel ow this SP, motor is

considered OFF. When above, motor is

which alarm occurs.
Active only if ST > SP 7 at start.

At start,Surge Temp(ST) is compared to this
SP.(ST=Sctn Temp-Evap LWT)
if Less:Alarm oc curs when ST>2X this SP.
if Greater:Slope alarm is active until ST<thi s SP.
Then alarm at 2X this SP.

forced capacity increase
Sets the condenser pressure above which the

compressor is shut down.
the compressor is shut down.
a forced capacity decrease oc curs.
any capacity increase is

28 OMM 1034-2

Pass-

word

Condenser EWT at which i ni t i al val ve pos i tion is set to setpoint
#10

Initial valve position when condenser EWT is at or above Setpoint

Temp – Min. Start
Position

Condenser EWT at which ini tial valve position is set t o Setpoint #
8

Minimum position of valve when condenser EWT is at or bel ow
Setpoint # 9

Valve position below which the fans can s t age down (Tower

# 2 = /VFD stage or valve SP/VFD stage

2 = VFD or valve SP/VFD st age

Setpoint # 5

with Setpoint # 4

Tower)

Figure 18, Tower Bypass VALVE Setpoint Screen

Table 15, Tower Bypass VALVE Setpoints (See page 31 for complete explanation.)

Description No. Default Range

Valve Control Slope Gain 15 25 10 to 99 O Control gain for temperature (or lift) slope
Valve Control Error Gain 14 25 10 to 99 O Control gain for tem perat ure (or lift) error
Valve Control Range(Max) 13 90% 0 to 100% O Maximum valve position, overrides all other sett i ngs
Valve Control Range (Min) 12 10% 0 to 100% O Minimum valve position, overrides all ot her s ettings

Temp–Max. Start Position 11
Maximum Start Posit i on 10 100% 0 to 100% O

Minimum Start P osition 8 0% 0 to 100% O

Stage Down @ 7 20% 0 to 100% O

Stage Up @ 6 80% 0 to 100% O

Valve Deadband (Lift) 5 4.0 psi 1.0 to 20.0 psi O Sets control deadband, Tower Setpoint #1=Lift
Valve Deadband (Temp) 4

Valve Target (Lift) 3 30 psi 10 to 130 ps i O
Valve Target (Temp) 2
Tower Valve Type 1

90 °F 0 to 100 °F

9

60 °F 0 to 100 °F

2.0 °F 1.0 to 10.0 °F

65 °F 40 to 120 °F

NC (To

NC, NO O Normally c l osed or normally open to tower

O

# 11

O

Setpoint #2 = Valve Stage
VFD speed below which the fans can stage down (Tower Setpoint

Valve position above which the fans can stage up (Tower Setpoint
#2 = Valve Stage
VFD speed above which the fans can stage up (T ower Setpoi nt #

O Sets control deadband, Tower Setpoint #1=Temp

Target for lift pressure (Tower Setpoi nt #1= Li f t), Works with
Target for condenser EWT (Tower Setpoint #1= Temp), Works

O

Comments

OMM 1034-2 29

word

down

up

None,

Stage

None,

None: No tower fan control

Figure 19, Cooling Tower Setpoint Screen (See page 31 for compl et e explanation.)

Table 16, Tower Fan Settings

Description No. Default Range

Stage #3 On (Lift) 13 55 psi 10 to 130 psi O Lift pressure for fan st age #3 on
Stage #2 On (Lift) 12 45 psi 10 to 130 psi O Lift pressure for fan s t age #2 on
Stage #1 On (Lift) 11 35 psi 10 to 130 psi O Lift pressure for fan st age #1 on
Stage #3 On (Temp) 10
Stage #2 On (Temp) 9
Stage #1 On (Temp) 8
Stage Differential (Lift ) 7 6.0 psi 1.0 to 20.0 psi O Fan st agi ng deadband with S etpoint # 1=Lift
Stage Differential (Temp) 6

Fan Stage Down Time 5 5 min 1 to 60 min O
Fan Stage Up Time 4 2 min 1 t o 60 min O

Cooling Tower Stages 3 2 1 to 3 O Number of f an stages used

Twr Valve/Fan VF D
Control

Tower Control 1 None

80 °F 40 to 120 °F
75 °F 40 to 120 °F
70 °F 40 to 120 °F

3.0 °F 1.0 to 10.0 °F

2 None

Valve Setpoint,

Valve Stage,

VFD Stage,

Valve SP/VFD

Temperature,

Lift

Pass-

O Temperature for f an stage #3 on
O Temperature for f an stage #2 on
O Temperature for f an stage #1 on

O Fan staging deadband with Setpoi nt #1=Temp

Time delay between stage up/down event and next stage
Time delay between stage up/down event and next stage

None: No tower valve or VFD
Valve Setpoint: Valve cont rol s to VALVE SP3(4) & 5(6)
Valve Stage: Valve controls between fan stages

O

VFD Stage: 1
Valve Setpoint/VFD St age: Both valve and VFD

Temperature: Fan and valve controlled by condenser EWT

O

Lift: Fan and valve controlled by lift pressure

st

fan is VFD controlled, no valve

Comments

30 OMM 1034-2

Explanation of Tower Control Setti ngs

The MicroTech control can control cooling tower fan stages, a tower bypass valve, and/or a tower fan VFD if the
chiller has a dedicated cooling tower.

The Tow er Bypass Valve position will always control the Tower Fan Staging if Valve Setpoint, Stage Setpoint is
selected. Fan staging is determined by Min & Max Tower Valve Position.

There are five possible tower control strategies as noted below and explained in detail later in this section. They are
selected from SETPOINT TOWER SP2.

1. NONE, Tower fan staging only. In this mode the tower fan staging (up to 3 stages) is controlled by either the

condenser Entering Water Temperature (EWT) or LIFT pressure (difference between the condenser and evaporator
pressures). Tower bypass or fan speed are not controlled.

2. VALVE SP, Tower staging with low-limit controlled bypass valve. In this mode the tower fans are controlled as in

#1 plus a tower bypass valve is controlled to provide a minimum condenser EWT. There is no interconnection
between the fan control and the valve control.

3. VALVE STAGE, Tower staging with stage controlled bypass valve. In this mode the bypass valve controls between

fan stages to smooth the control and reduce fan cycling

4. VFD STAGE. In this mode a VFD controls the first fan. Up to 2 more fans are staged on and off and there is no

bypass valve.

5. VALVE/VFD, Tower fan control with VFD plus bypass valve control.

Tower Fan Staging Only (NONE)

The following settings are used for the Tower Fan Staging Only mode, (SP= setpoint)

1) TOWER SETPOINT Screen

2) See Figure 6, Field Wiring Diagram on page 16 for fan staging field wiring connection points.
a) SP1. Select TEMP if control is based on condenser EWT or LIFT if based on compressor lift expressed as a

pressure difference.

b) SP2. Select NONE for no bypass valve or fan VFD control.
c) SP3. Select one to three fan outputs depending on the number of fan stages to be used. More than one fan can

be used per stage through the use of relays.

d) SP4. Select STAGE UP TIME from 1 to 60 minutes. The default value is probably a good starting point. The

value may need to be adjusted later depending on actual system operation.

e) SP5. Select STAGE DOWN TIME from 1 to 60 minutes. The default value is probably a good starting point.

The value may need to be adjusted later depending on actual system operation.

3) If TEMP is selected in SP1, use
a) SP6. Select STAGE DIFFERENTIAL in degrees F (degrees C), start with default of 3 degrees F.
b) SP8-11. Set the STAGE ON temperatures consistent with the temperature range over which the condenser

EWT is desired to operate. The default values of 70°F, 75°F and 80°F are a good place to start in climates with
moderate wet bulb temperatures. The number of STAGE ON setpoints used must be the same as SP3.

4) If LIFT is selected in SP1, use
a) SP7. Select STAGE DIFFERENTIAL in PSI (kPa). Start with default of 6 PSI.
b) SP11-13. Start with default setpoints. The number of STAGE ON setpoints used must be the same as SP3.

OMM 1034-2 31

Tower Fan Staging With Bypass Valve Controlling Minimum EWT (VALVE SP)

1) TOWER SETPOINT Screen
a) SP1. Select TEMP if control is based on condenser EWT or LIFT if based on compressor lift expressed as a

pressure difference.

b) SP2. Select Valve SP for control of bypass valve based on temperature or lift.
c) SP3. Select one to three fan outputs depending on the number of fan stages to be used. More than one fan can

be used per stage through the use of relays.

d) SP4. Select STAGE UP TIME from 1 to 60 minutes. The default value of 2 minutes is probably a good starting

point. The value may need to be adjusted later depending on actual system operation.

e) SP5. Select STAGE DOWN TIME from 1 to 60 minutes. The default value of 5 minutes is probably a good

starting point. The value may need to be adjusted later depending on actual system operation.

f) If TEMP is selected in SP1, use:

i) SP6. Select STAGE DIFFERENTIAL in degrees F (C), start with default of 3 degrees F.
ii) SP8-11. Set the STAGE ON temperatures consistent with the temperature range over which the condenser

EWT is desired to operate. The default values of 70°F, 75°F, and 80°F are a good place to start in climates
with moderate wet bulb temperatures. The number of STAGE ON setpoints used must be the same as SP3.

g) If LIFT is selected in SP1, use

i) SP7. Select STAGE DIFFERENTIAL in PSI (kPa). Start with default of 6 PSI.
ii) SP12-15. Start with default setpoints. The number of STAGE ON setpoints used must be the same as SP3.

2) VALVE SETPOINT Screen
a) SP1, Select NC or NO depending if valve is closed to tower with no control power or open to tower with no

control power.

b) If TEMP was selected for fan control above, use:

i) SP2, Set the VALVE TARGET (setpoint), usually 5 degrees F below the minimum fan stage setpoint

established in TOWER SP8. This keeps full flow through the tower until the last fan is staged off.

ii) SP4, Set VALVE DEADBAND, the default of 2 degrees F is a good place to start.
iii) SP8, Set MINIMUM START POSITION when EWT is at or below SP9. Default is 0%.
iv) SP9, Set the EWT at which the valve position will be at (SP8). Default is 60°F.
v) SP10, Set the initial valve position when EWT is at or above SP11. Default is 100%.
vi) SP11, Set the EWT at which initial valve position is set to SP8. Default is 90°F.
vii) SP12, Set the minimum position to which the valve can go. Default is 10%.
viii) SP13, Set the maximum position to which the valve can go. Default is 90%.
ix) SP14, Set the control gain for error. Default is 25.
x) SP15, Set the control gain for slope. Default is 25.

NOTE: Setpoints 14 and 15 are site specific dealing with system fluid mass, component size and other factors affecting
the reaction of the system to control inputs. These setpoints should be set by personnel experienced with setting up this
type of control.

3) If LIFT was selected for fan control, use
a) SP3, Set the VALVE TARGET (setpoint), usually 30 psi below the minimum fan stage setpoint established in

TOWER SP11. This keeps full flow through the tower until the last fan is staged off.

b) SP5, Set VALVE DEADBAND, the default of 6 psi is a good place to start.
c) SP8, Set MINIMUM START POSITION when EWT is at or below SP9. Default is 0%.
d) SP9, Set the EWT at which the valve position will be at (SP8). Default is 60°F.
e) SP10, Set the initial valve position when EWT is at or above SP11. Default 100%.

32 OMM 1034-2

Initial Valve Posit i on

Set Point (90%)

Set Point (10%)

Start Position

@ Setpoint

(90°F)

@ Setpoint

(60°F)

f) SP11, Set the EWT at which initial valve position is set to SP8. Default is 90°F.
g) SP12, Set the minimum position to which the valve can go. Default is 10%.
h) SP13, Set the maximum position to which the valve can go. Default is 100%.
i) SP14, Set the control gain for error. Default is 25.
j) SP15, Set the control gain for slope. Default is 25.

NOTE: Setpoints 14 and 15 are site-specific dealing with system fluid mass, component size and other factors affecting
the reaction of the system to control inputs. These setpoints should be set by personnel experienced with setting up this
type of control.

Temp-Max

Temp-Min

Min Start Position

Max Start Position

See Figure 6 on page 16 for fan staging and bypass valve field wiring connection points.

Tower Staging with Bypass Valve Controll ed by Fan Stage (VALVE STAGE)

This mode is similar to #2 above except that the bypass valve setpoint changes to be set at the same point of whatever
fan stage is active rather than just maintaining a single minimum condenser EWT. In this mode the valve controls
between fan stages and tries to maintain the fan stage setting in effect. When it is max open or max closed (staging up
or down) and the temperature (or lift) moves to the next fan stage, the valve will go the opposite extreme setting. This
mode reduces fan cycling.

This mode is programmed the same as Mode #2 above except that in SETPOINT, TOWER, SP2, VALVE STAGE is
selected instead of VALVE SP.

Fan VFD, No Bypass Valve (VFD STAGE)

The fan VFD mode assumes the tower is driven by one large fan. Set-up is as above except in SETPOINT, TOWER,
SP2, VALVE/VFD is selected.

OMM 1034-2 33

Pass-

word

Sets the over voltage limi t

Sets the Rated Load Amps (RLA) per compressor
Phase Data.

Overload Factor.

Correct to minimum speed calculation

Sets the minimum speed at which the VFD can operate. Has
priority over SPs 8 & 9.

Sets the time period over which t he %RLA limit is
SPs 5 & 6.

Sets the initial %RLA limit for the soft load ramp. Used with
SPs 5 & 7.

ON: Soft loading is ON using SPs 5 & 6.
OFF: Soft Loading is disabled.

Inhibites capacity i nc rease above the %RLA
Unloading is forced at 5% above thi s value.

Sets the %RLA below which unloading is i nhi bi ted.

OFF: The Demand Limit i nput is ignored.

Figure 20, Power Setpoint Screen

Table 17, Power Setpoints

Description No. Default Range

Over Voltage Limit 11 550 342 to 633 Volts

Nameplate RLA 10

Overload Factor 9 1.1 1.001 to 1.249 T
VFD Min Speed offset % 8 0 -5 to +5
VFD Minimum Speed 7 70% 70 to 100 % T

Soft Load Ramp Time 6 5 1 to 60 Minutes O

Initial Soft Load Limit 5 40% 10 to 100 % O
Soft Load Enable 4 OFF ON, OFF O
Maximum Amps 3 100% 10 to 100 % T

Minimum Amps 2 5% 5 to 80 % T

Demand Limit Enable 1 Off ON, OFF O

280

Amps

100 to 600 Amps T

Comments

phase as given on the McQuay nameplat e - Load Side
VFD over-current trip occurs at Nameplate RLA times

increased from the S P 5 value to 100%. Used with

ON: Limits % RLA to a value set by the Demand Limit
analog input, where:
4mA = 0 %RLA
20mA = 100 %RLA

34 OMM 1034-2

word

Sequence # takes priority over st agi ng mode.

NORMAL: Uses only sequence number and/ or balance

STANDBY: Use this c ompr only if another fails.

ON

compressors) minus (# of standby com pres sors).

Figure 21, Staging Setpoint Screen

Table 18, Staging Setpoints

Description No. Default Range

Compr #1 Stage
Sequence #

Compr #1 Staging Mode 2 Normal

Maximum Compressors

3 1

1 1 to 64 O

1 to No of

Comp. In

System

NORMAL

HI-EFF

PUMP

STANDBY

Pass-

O

O

Comments

Sets a sequence (order) for compressors staging ON/OFF .
Compressors with the same sequence # will auto
balance starts/hours .

starts/hours
HI EFF: Starts 1 c ompressor on each dual first .
PUMP: Starts all compressors on one chiller fi rs t.

For a standby system, normally set to: (total # of

OMM 1034-2 35

word

turns OFF (goes to postlube).

Timer

until it can restart.

Timer

until it can start agai n.

Evap
Timer

Capacity

decide when to turn OFF a compress or (s tage down)

Figure 22, Unit Setpoint Screen

Table 19, Unit Setpoints

Description No. Default Range

Liquid Injection 16 Off Off, Auto T

EXV Total Offset 15 0 0 to 100% O T he EXV position is offset by thi s constant amount.
EXV Balance

Offset

EXV Balance
Gain

Unload Timer 12 30 sec 10 to 240 Seconds O
Stop To Start

Start To Start

Recirculate

Nominal

14 0 -10 to 10 Deg F O

13 2 0 to 5 O

11 1 Min 0 to 20 Minutes O

10 1 Min 0 to 60 Minutes O

9 0.5 min 0. 2 to 5.0 Minutes O

8 500/700 0-9999 O

Continued next p age.

Pass-

Comments

Condenser Approach and

A more positive value rais es

- Suction Superheat +

EXV Balance Offset).

a compressor stops

Sets the amount of time the evaporator pump m ust run
before a compressor can start.

starts

Used to

36 OMM 1034-2

Pass-

word

#1 ONLY: Use only pump #1

#2 PRIMARY: Use #2. If it fails , then use #1

#2 PRIMARY: Use #2. I f it fails, then use #1.

COOL/HEAT

BAS: Control is from the B A S network.

COOL: Maintains evaporator LWT at WATER-SP1.

OFF: Compressors, pumps, & fans are OFF.

water temperature.

Description No. Default Range

Condenser
Pump

Evaporator
Pump

Available
Modes

Control
Source

Unit Mode 2 COOL Cool, ICE, HEAT O

Unit Enable 1 OFF OFF AUTO O

6 #1 Only

5 #1 Only

COOL

4

3 USER USER, SWITCH, BAS O

only

#1 ONLY, #2 ONLY

AUTO
#1 PRiMARY,
#2 PRIMARY

#1 ONLY, #2 ONLY

AUTO
#1 PRiMARY,
#2 PRIMARY

COOL only,: ICE only,
COOL/ICE
HEAT only

Figure 23, Water Setpoint Screen

Comments

#2 ONLY: Use only pump #2

O

AUTO: Balance hours bet ween #1 and #2.
#1 PRIMARY: Use #1. If it fails, then use #2.

#1 ONLY: Use only pump #1
#2 ONLY: Use only pump #2
AUTO: Balance hours bet ween #1 and #2.

O

#1 PRIMARY: Use #1. If it fails, then use #2.

T

Sets which modes can be s el ected using SP2.

Sets control source f or Unit Enable, Mode, & LWT SPs.
USER: Control is from touchscreen or remote user

As USER except Mode is controlled by the Mode digital input .

AUTO: Evap pump is ON, Compressors, condenser
pump, & fans will operate as needed t o maintain

Detail table on following page.

OMM 1034-2 37

Condenser Flow
Full Scale

Full Scale

Maximum Reset
Delta-T

Reset Type (SP9) = Return: Sets the maximum LWT reset that can occ ur.
Reset Type (SP9) = 4-20mA: S et s amoumt of reset at 20mA input.

Reset raises LWT setpoint
4-20mA (4mA=None,20mA=Max asset by SP 11)

Rate

Deg F/min

If the LWT rat e i s above this value, capacity inc rease is inhibited.

Rate

Deg F/min

Sets the value below which an additional compressor can stage on.

compressor to st art.

Sets amount leaving water m ust drop below setpoint for last compressor to

Leaving Water

Sets control target f or evaporator l eavi ng water temperature

Table 20, Water Setpoints

Description No. Default Range Password Comments

11 3000 200 to 10,000 GPM O Sets the f ul l scale (20mA) value for the c ondens er flow rate analog input

Evaporator Flow

Start Reset
Delta-T

LWT Reset Type 7 None
Maximum LWT
Minimum LWT

Stage Delta-T 4 1.0 0.5 to 5.0 Deg F O
Startup

Delta-T
Shutdown Delta-T 2 3 Deg F 0.0 to 3. 0 Deg F O

Temp - COOL

10 3000 200 to 10,000 GPM O Sets the full scale (20mA) value for the evaporator flow rate analog input

9 0.0 0.0 to 20.0 Deg F O
8 10 0.0 to 20.0 Deg F O Sets evaporator delta-T above which Return reset begi ns .

Return

4-20mA
6 5.0
5 0.1

3 3 Deg F 0.0 to 10.0 Deg F O

1

44 °F

0.1 to 5.0

0.1 to 5.0

35 to 80 Deg F O

O

Return (uses SPs 10 & 11)

O
O

Sets amount leaving water m ust go above set point for next

Sets amount leaving water m ust go above for first compressor to start.
stop.
in COOL mode.

Service Screens

Figure 24, Service Screen

Screen explanation on following page.

38 OMM 1034-2

A matrix in the middle of the screen shows the chillers and compressors attached to the network. A green box indicates
that a given controller is present and communicating. This is an effective means for verifying communication between
units and compressors on the same network.

The Operating Manual button will access the operating and maintenance manual for the unit. The Parts List button
allows the operator to access the replacement parts list.

SELECT LANGUAGE allows toggling between the available languages. The language can be set separately for
display or history, which is used for alarm and trend files.

The UNAUTHORIZE/AUTHORIZE button is used to access the Keyboard screen to enter a password.

• O= Operator password : default = 100

• T = Technician level password is reserved for authorized technicians

Date/Time in the upper-right corner is pressed to set the correct date and time, if needed.

Downloading Data

Trend data can be downloaded for review and storage as a personal computer file or printed as a hard copy for future
reference. This is valuable for troubleshooting potential problems or reviewing the chiller’s general performance.

Depending on the number of compressors and the chiller duty cycle, 15 to 30 days of history data can be downloaded
from the controller, one day at a time.

To download history data from the chiller:

1) Install a USB memory stick into an open USB slot on the chiller controller. These slots are located on the top

and bottom of the metal bracket holding the main chiller controller. Do not remove the main memory stick
located behind the metal bracket. A minimum of 2 MB per day should be available on the USB memory stick
for data accumulation.

2) Navigate to the OITS ALARM screen.

3) Highlight a day on the calendar. Data is downloaded one day at a time.

4) Press download button. The controller will display a notification of "download complete" at the end.

To analyze downloaded data:

1. The chiller data is in binary format and must be compiled into spreadsheet format with a separate program.

Download "WME Trend Tool" from

www.daikinmcquay.com/Magnitude on the Download tab, under

Application Software.

Troubleshooting:

1) "Error mounting the USB drive". Action: Remove and reinstall USB memory stick and repeat. If problem

persists, try a different USB memory stick. Name brand memory sticks are recommended.

2) No data appears on the disk after download. Cause: no data available for that day.

OMM 1034-2 39

Chiller Faults and Alarms

Figure 25: Active Alarm Screen

The Active Alarm screen is accessible when an active alarm exists on the unit by pressing the red alarm signal on any
screen. Pressing any FAULT or ALARM on the screen will open another screen that will show the condition of the
chiller at the time of fault.

The last eight alarms are arranged in order of occurrence, with the most recent on top. Once the abnormal condition is
corrected, pressing the "CLEAR" key will clear the alarm. Both current active alarms and cleared alarms (there may be
more than one of each) are displayed. Alarms with a red bar to the left are current, uncleared alarms. Cleared alarms
have a black bar.

• FAULT, in red for (equipment protection control) that causes a compressor shutdown,

• ALARM will inhibit loading, or load or unload the compressor to correct a potential problem or indicates a

condition requiring attention but not serious enough to cause a shutdown.

The date/time and cause of the alarm are displayed. Pressing any alarm will open a snapshot screen showing the unit
operating parameters at the time of failure. Touching the gray area of this screen will close it. After eliminating the
cause of the alarm, clear the alarm by pressing the CLEAR button. This will clear the alarm from the register and allow
the unit to restart after going through the start sequence. The alarm button will return to its normal color.

However, if the cause of the alarm is not remedied, the alarm is still active and the alarm message will remain active.
The unit will not begin its starting sequence.

Always remedy the cause of an alarm before attempted to clear it.

Event Types

Events fall into two distinct types of action depending on their severity.

• A Fault shuts down the unit with either a rapid shutdown or a pumpdown shutdown. The fault must be

investigated and corrected before clearing the alarm.

• Alarms do not cause compressor shutdown but limit operation of the chiller in some way or warn of a situation

that must be corrected. Although not causing a shutdown, they will prevent a startup after the next shutdown if
not corrected. An alarm will trigger the alarm screen and the digital output for the optional remote alarm.

See Table 21 for alarm details.

40 OMM 1034-2

LWT:

ELSE (alarm if ST slope > Surge S l ope Li mit

Motor did not start. Causes: VFD control

Table 21, Alarm Details and Troubleshooting Guide

Severity Clear Screen Text Occurs When Troubleshooting

Shutdown Manual

Shutdown Manual Mechanical High Pressure

Shutdown Manual High Motor Temperature

Shutdown Manual

Shutdown Manual

Shutdown Manual Surge Temperature

Shutdown Manual Motor Start F ai l ure

Shutdown Manual No Com pres sor Stop

Shutdown Manual VFD Fault

Shutdown Manual VFD Reference Fault

Shutdown Manual VFD Loss of Mot or S ync Loss of VFD phase lock loop synchronizat i on

Shutdown Manual VFD Motor Stall

Shutdown Manual

Continued next page.

High Discharge

Temperature

High Motor Gap

Temperature

Low Rotor Pump

Superheat

VFD Speed Command

Fault

Temp > High Discharge Tem perat ure SP
Digital Input on VFD= High Pres s ure Causes: Loss of condenser water flow

(this switch connects directly to the VFD) HPS failure
(from MBR 201/15) Condenser water flow low.

Analog Motor Temp (any sensor) > Motor Tem p
SP

Motor Gap Temperature > 130°F

Rotor Pump Superheat (Rotor Pump Temp –
Saturated Suction Temp) < 5°F for 5 minutes
with compressor running

FOR Surge Temp (ST) = Sct n T emp – Evap

IF (ST < Surge Temp Limit SP at compressor
start)

THEN (alarm if S T > 2 X Surge Temp Limit SP)

SP
until ST < Surge Temp Limit SP , then Condenser foul i ng

alarm if ST > 2 X Surge Temp Li mit SP).
(Motor speed not = speed comm and

AND Compressor ON) for > 15 seconds

%RLA > Motor Current Threshold SP with

Compressor OFF for 30 sec

VFD Fault AND Compressor S tate = FLOAT,

START, RUN, or UNLOAD

Failure to calculate speed pul se reference

position at 900 rpm (

No speed pulse detected when motor shoul d be

running (

Commanded speed fault

Causes: Low or No Condenser Water
Flow

Rotor and/or stator cooling ci rc ui t fault
Causes: Motor stator cooling solenoid

not open, rotor cooling stepper motor not
functioning correctly, Motor rot or
superheat or gain setpoints i ncorrect (
contact factory)

Rotor and/or stator cooling ci rc ui t fault.
Causes: Motor stator cooling solenoid

not open
Motor rotor cooling stepper motor not

opening, Motor rotor superheat or gain
setpoints incorrect ( c ontact factory)

Rotor cooling circuit fault.
Causes: rotor cooling valve stuck open,

Motor rotor superheat or gain setpoints
incorrect ( contact f actory)

Compressor Surge detected.
Causes: Compressor Surge/ Stall line not

set properly. See setpoint s ection.
Loss of condenser or evaporator GPM

Low Evaporator or condenser GPM

failure, Check VFD enable s i gnal wiring,
Check VFD breaker

Motor running while it should be off.

Causes: VFD enable relay failure

VFD CTs failure

VFD loss of com munications.

General VFD fault. Normall y

accompanied by another fault.

Speed pulse feedback not present :

Causes: Speed sensor fault , Speed

sensor wiring fault, VFD control l er fault

Speed pulse loss while running

Causes: Speed sensor fault , Speed

sensor wiring fault, VFD control l er fault

Speed pulse feedback not present :

Causes: Speed sensor fault

Speed sensor wiring fault

VFD controller fault

Motor speed outside of expected range.

Causes: Speed sensor fault ,

Speed sensor wiring fault,

VFD controller fault

OMM 1034-2 41

failure

persistent.

Severity Clear Screen Text Occurs When Troubleshooting

Fan is stopped. Causes: Check fan CT

Shutdown Manual V F D Cooli ng F an F aul t Failure of fan monitor circuit

wiring, check CT for open circuit, fan

Shutdown Manual VFD Processor Fault VFD processor hardware or soft ware trap faul t

Shutdown Manual VFD Maintenance Mode

Shutdown Manual

Shutdown Manual

Shutdown Manual

Shutdown Manual

Shutdown Manual

Shutdown Manual

Shutdown Manual

Shutdown Manual

Shutdown Manual Mag Bearings Fault

Suction Pressure Sens or

Fault

Discharge Pressure

Sensor Fault

Condenser Rfr Ckt #1

Pressure Sensor Fault

Condenser Rfr Ckt #2

Pressure Sensor Fault

Suction Temperature

Sensor Fault

Discharge Temperature

Sensor Fault

Motor Gap Temperature

Sensor Fault

Rotor Pump Temperature

Sensor Fault

Maintenance mode switch act i vat ed (B 17 –

MBR 201/14)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Sensor shorted or open

(Input voltage < 0.2 OR > 4.6 volts)

Mag bearings exceed allowable orbit or sensor

fault

Causes: Processor faul t or overheating.

Check fan operation for proper airflow. If

persistent, replace c ont rol l er.

Jumper missi ng. See VFD schematic.

Jumper required for normal chi l l er

operation

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Compressor dynam i c load

change. Compressor surge. Improperly

set stall/surge line setpoints

Bearing controller fault or bearing

amplifier fault. Cont act factory if

Shutdown Manual Communications Faul t

Shutdown Manual

Shutdown Manual

Shutdown Manual Controller Fault Control l er i nt ernal check failure

Shutdown Manual

Shutdown Manual

Limit Auto

Continued next page.

Evaporator Leaving Water
Temperature Sensor Fault

Condenser Leaving Water
Temperature Sensor Fault

Evaporator Water Flow

Loss

Condenser Water Flow

Loss

Low Evaporator Pressure

– Inhibit Loading

Loss of comm uni cations between compressor

and chiller controller

Sensor shorted or open (Input voltage < 0.2 OR

> 4.6 volts) AND Unit Mode = COOL or ICE

Sensor shorted or open (Input voltage < 0.2 OR

> 4.6 volts) AND Unit Mode = Heat

Evaporator Flow DI = No Flow for > 12 sec with

compressor running

Condenser Flow DI = No Flow for > 20 sec with

compressor running OR no flow in START state

at a point (Pre-Start Timer SP + 30 sec) after

Pressure Ratio is OK

Suction Pressure < (Low Evap Press SP)+3psi

Check wiring and verify correct software

versions

Causes: Sensor wiring fault, s ensor fault

Causes: Sensor wiring fault, s ensor fault

Causes: Compressor controller fault. If

persistent, contact factory.

Causes: Loss of evaporator flow,

evaporator pump off, evap head gasket

leaking or missing, sensor wiring fault,

evaporator flow sensor failure

Causes: Loss of condens er f l ow,

condenser pump off, condenser head

gasket leaking or missing, sensor wiring

fault, condenser flow sensor f ai l ure

Causes: Low evaporator water flow rate,

low refrigerant in chiller, setpoints

incorrect for operating condit i ons

42 OMM 1034-2

Evaporator Entering

Severity Clear Screen Text Occurs When Troubleshooting

Limit Auto

Evaporator Freeze

Protect

Saturated Suction Temp < Evaporator Freeze

SP

Causes: Low evaporator water flow rate,

low refrigerant in chiller, setpoints

incorrect for operating condit i ons

Limit Auto

Limit Auto

Warning None S ystem Unhealthy Controller internal check failure

Limit Manual Evaporator Pump #1 Fault

Limit Manual Evaporator Pump #2 Fault

Limit Manual Condenser Pum p #1 F aul t

Limit Manual Condenser Pum p #2 F aul t

Condenser Freeze

Protect

High Discharge

Temperature

Saturated Cond Temp < Condenser Freeze SP

Temperature > High Discharge Temperature-

Load SP AND

Suction superheat < 15°F

No flow indicated for (5 sec) with Evaporator

Pump #1 ON AND [the other pump i s available

(per the Evap Pump SP) AND has not f aul ted]

No flow indicated for (5 sec) with Evaporator

Pump #2 ON AND [the other pump i s available

(per the Evap Pump SP) AND has not f aul ted]

No flow indicated for (5 sec) with Condenser

Pump #1 ON AND [the other pump i s available

(per the Evap Pump SP) AND has not f aul ted]

No flow indicated for (5 sec) with Condenser

Pump #2 ON AND [the other pump i s available

(per the Evap Pump SP) AND has not f aul ted]

Causes: Low evaporator water flow rate,

low refrigerant in chiller, setpoints

incorrect for operating condit i ons

Causes: Low or No Condenser Water

Flow

Causes: Compressor c ont rol fault.

Contact factory if persi stent.

Evaporator flow not detected.

Causes: improper pump wiring

Evaporator flow not detected.

Causes: improper pump wiring

Condenser flow not detected.

Causes: improper pump wiring

Condenser flow not detected.

Causes: improper pump wiring

Limit Manual

Warning Auto

Warning Auto

Warning Auto

Warning Auto

Warning None System Fault Controller internal fault

Water Temperature

Sensor Fault

Evaporator Entering

Temperature Sensor Fault

Condenser Entering

Temperature Sensor Fault

Condenser Leaving

Temperature Sensor Fault

Liquid Line #1 Refrigerant

Temperature Sensor Fault

Sensor fault (Input voltage < 0. 2 O R > 4. 6 vol t s)
AND the LWT Reset T ype S P i s set to RETURN

Sensor is open or shorted

(Input voltage < 0.2 OR > 4.6 volts)

Sensor is open or shorted

(Input voltage < 0.2 OR > 4.6 volts)

Sensor is open or shorted

(Input voltage < 0.2 OR > 4.6 volts)

Sensor is open or shorted

(Input voltage < 0.2 OR > 4.6 volts)

Causes: Sensor wiring fault, sensor fault

Causes: Sensor wiring fault, sensor fault

Causes: Sensor wiring fault, sensor fault

Causes: Sensor wiring fault, sensor fault

Causes: Sensor wiring fault, sensor fault

Causes: controller fault . If persistent

contact factory.

OMM 1034-2 43

Trend Screens

Figure 26, Trend History Screen

This screen plots the parameters shown over various time frames; 8 = eight hours, 2 = two hours,
1/3 = 20 min., < and > move the screen to the right or left. NOW displays current status.

44 OMM 1034-2

Operating the Chiller

Interface Panel On/Off

The Operator Interface Panel is turned on and off with a push-push switch located at the upper-left corner on the rear
of the panel. ON is the outermost switch position and a white band will be visible on the switch stem. Off is innermost
and no white is visible.

The screen is equipped with a screen saver that blackens the screen. Touching it anywhere reactivates the screen. If the
screen is black, touch it first to be sure it is on before using the ON/OFF switch.

Start/Stop Unit

There are four ways to start/stop the chiller. Three are selected in SETPOINT\MODE\SP3, the fourth way is through
panel-mounted switches:

Operator Interface Panel (LOCAL)

Home Screen 1 has AUTO and STOP buttons that are only active when the unit is in "LOCAL CONTROL". This
prevents the unit from being accidentally started or stopped when it is under control from a remote switch or BAS.
When these buttons are pressed, the unit will cycle through its normal starting or stopping sequence.

Remote SWITCH

Selecting SWITCH in “Unit/ Control Source” (SP3) will put the unit under the control of a remote switch that must be
wired into the control panel (see Figure 6 on page 16).

BAS

BAS input is field-wired into a card that is factory-installed on the unit controller.

Control Panel Switches

The unit control panel, located adjacent to the Interface Panel has switches inside the panel for stopping the unit and
compressors. When the UNIT switch is placed in the OFF position the chiller will shut down through the normal
shutdown sequence.

The COMPRESSOR switch will immediately shut down the compressor without going through the shutdown sequence
when placed in the OFF position. It is equivalent to an emergency stop switch.

A third switch is mounted on the side of the unit controller. It is wired in parallel to the UNIT switch inside the panel
and causes an immediate shutdown.

Changing Setpoints

Set points are easily changed on the Operator Interface Touch Screen (OITS). A complete description of the procedure
begins on page 24.

Sequence of Operation

Start-up of Magnitude Compressors:

“Next On” Status

If none of the “OFF” conditions are true, then all the MicroTech compressor controls in a network of units will pole
the status of each to determine the one having “Next On” status, which is usually the compressor with the least starts.
This takes about one minute.

Evap (Evaporator) Pump Start

Once this is determined, the unit controller of the chiller with the “Next On” compressor (when there are multiple
chillers) will start the evaporator pump and determine if there is load based on the water temperature. This is

OMM 1034-2 45

determined if the leaving evaporator water is above the “LWT Setpoint” plus “Startup Delta T”. If there is no load,
based on the temperature, the unit is in the state of ‘Awaiting Load’.

Bearing Levitation

If there is load, the unit waits for the Evaporator Recirculation Timer period (default value of 30 seconds) and then
executes bearing levitation.

Cond (Condenser) Pump Start

After levitation is confirmed, the controller starts the Condenser Pump and checks for condenser flow before starting
the first compressor.

Compressor Start

The compressor starts when the following conditions are met:

1) Condenser flow present for 5-seconds (condenser state is RUN)

2) Vanes are at the start position

3) Pre-start timer expired

Starting the compressor is accomplished by closing the VFD enable relay in the compressor controller. The VFD ramps
to 900 rpm, waits at this speed until motor synchronization occurs, then ramps up to the VFD minimum speed value.

Compressor Run

The compressor that is running will signal all other compressors (when multiple chillers are networked together) when
it reaches full load.
Full load status is determined when any one of the following tests is true:

1) Percent RLA exceeds 100% or the Active-Amp-Limit from an external-limiting source.

2) Evap Saturation pressure drops below the Evap Hold-Loading pressure setpoint.

3) Actual compressor RPM exceeds 99% of Max RPM limit for the compressor and the vanes are within 5% of

the Maximum Vane Position setpoint.

Staging Compressors Off:

The setpoint of ‘Nominal Capacity’ is used for defining the point to stage off a compressor on a multi-chiller system.
With each compressor having its ‘Nominal Capacity’ defined, then the network, which is load balanced, continues to
unload at 0.2 tenths or more below setpoint. Each compressor keeps computing the spare capacity of the network.
When the designated ‘Next Off’ sees enough spare capacity, it will turn off. Then similarly, in about 40 seconds, a new
compressor will be designated as the ‘Next Off’ and the spare capacity will continue to be calculated between the
remaining compressors. Compressors continue to unload and stage off until there is only one compressor running. It
will shut off when the water temperature reaches the LWT Setpoint minus the Shutdown Delta T. The remaining
compressors continue to unload and stage off until there is only one compressor running. It will shut off when the
water temperature reaches the LWT Setpoint minus the Shutdown Delta T.

Staging Compressors On

The Stage Delta-T setpoint is used to define when another compressor must stage on. The compressor with Next On
will start when the leaving water temperature exceeds the value of the active LWT plus the Stage Delta-T.

46 OMM 1034-2

Troubleshooting

The primary troubleshooting method is to use the interface panel (OITS) to determine the alarm status, I/O status, unit
state, and trend data.

If this method is not successful, the next step is to determine if all controllers are present, powered up, fully booted up,
and are communicating normally. All controllers have tell-tale LEDs that should be lit to determine powered-up state.

Control power starts from the Intermediate Power Supply (IPS) in the VFD panel with a few exceptions. The IPS
powers a variety of smaller power supplies for control power, the bearings, and most auxiliary systems.

The control power for the cabinet fans, ground fault, comes from a control power transformer.

Troubleshooting Chart

PROBLEM

Controls won't boot up
If no power Check DC voltage dist ribution board LEDs.

LEDs are not lit

One LED is not lit

POSSIBLE

CAUSES/CONDITION

POSSIBLE CORRECTIVE STEPS

Check state of LEDs on c hi l l er controller, compress or c ontroller, and VFD
controller. LEDs should be li t.

Check IPS.
Check fuses into IP S.
Check small fus e on IPS PCB ( 110V).
Check control power transformer.

Check fuses/breakers i nto power supplies.
If persistent, i dent i fy corresponding power supply and repair/replace.

Check OITS alarms .
Check control harness to V F D, enabl e signal, 24VDC power, rpm signal.

VFD will not start

Chiller will not start

VFD starts but shuts off
on alarm

Inlet Guide Vane (IGV)
alarm

Bearing alarm During operation, Out of orbit alarm due to surge/ s tall.

OITS data miss i ng

OITS data miss i ng If data is f rom chiller controller

Controller unhealthy alarm

IGV feedback doesn't m atch setpoint on I/O OIT S screen.

If data is from compressor
data

If data is from VFD

If data from power meter

Check VFD comm uni cation cable, Ethernet.
Check VFD voltage breakout board that al l LE D' s are lit.
Check that all VFD cont rol c abl es are plugged in and fully seated.

Check sequence of operation.
Check chiller OITS S t ate screen to determine what stat e the unit is in.
Check alarms.

Check Alarm codes.
Follow VFD troubleshooting chart.

Verify Compressor communication present.
Look for lit up green boxes in chiller cont rol l er on " SET" screen #2.
If not, check Ethernet cable and that compres sor controller board LEDs are lit.
If yes, reboot chiller.

Check communication cable.
Cycle power to reset VFD controller.
Verify LEDs lit on VFD c ont rol l er.
Check power supply.

Verify power meter comm uni cation cable wiring.
Verify power meter configuration.

Check that sensors are wired properly.
Check that LEDs are lit on chiller controller.
Check power supply.

Verify communications cable is properly connected.
Reboot chiller

OMM 1034-2 47

Operation with Failed OITS

The touchscreen does not have any control function; it is only a window into the unit’s controller and operation.
Chiller operation is not affected by a failed touchscreen. The touchscreen (OITS) is the primary user interface to the
chiller. If this screen is not operating as expected, use the following troubleshooting procedure:

Indication; Screen is blank, power indicator is green.
Procedure: Screen is in screen saver mode. Touch screen and image will appear.

Indication; Screen is blank, power indicator is unlit.
Issue: Screen has been powered off.
Procedure: Press power button on lower outside edge of screen.

Indication; Screen is blank, power indicator is unlit.
Issue: Screen is not receiving power,
Procedure: Ensure power cable is plugged into screen and controller.

Indication; Screen is blank, power indicator is unlit.
Issue: Unit controller is not powered.
Procedure: Check to see if LEDs are lit/blinking within chiller controller box. If not, contact chiller service.

Indication; Screen is blank, power indicator is unlit
Issue: Touchscreen failure
Procedure: Replace touchscreen.

Indication; Screen is working but touch function isn't working.
Issue: Disconnected serial cable.
Procedure: Ensure cable is connected, reboot chiller.

Indication; Screen is working but touch function isn't working.
Issue: Touchscreen failure
Procedure: Replace touchscreen. As temporary measure, install USB mouse on chiller controller to replace the touch

function. Plug USB mouse into spare USB port on chiller controller.

As a temporary replacement for a completely failed touchscreen,

1) Install a VGA monitor using cable from chiller controller box. (Blue plug)

2) Plug USB mouse into spare USB port on chiller controller.

48 OMM 1034-2

Suction

300VDC

Maintenance

External Sensors and Valve Locations

Discharge
Pressure

Discharge
Temp

High
Pressure
Switch

Power

VFD Control
Cable

Suction
Pressure

Temperature

IGV Stepper
Mtr Control &
IGV Position
Sensor

Compressor Sensor
Harness

Ethernet
Connection

OMM 1034-2 49

Flow Switch

Water
Temperature
Sensor

Liquid Line
Temperature
Sensor

Electronic
Expansion
Valve

50 OMM 1034-2

Stator

Compressor

Removed

Compressor
Liquid
Injection

VFD Cooling In

Rotor
Injection
Cooling

Cooling In

Liquid Line
Shut Off
Valve

Controller.
Cover

Rotor Cooling
Inlet

OMM 1034-2 51

Rotor Injection
Cooling

Rotor Cooling Outlet
Compressor Bottom)

Table 22, HFC-134a Pressure/Temperature Chart

HFC-134a Temperature Pressure Chart

°F PSIG °F PSIG °F PSIG °F PSIG

6 9.7 46 41.1 86 97.0 126 187.3

8 10.8 48 43.2 88 100.6 128 192.9
10 12.0 50 45.4 90 104.3 130 198.7
12 13.2 52 47.7 92 108.1 132 204.5
14 14.4 54 50.0 94 112.0 134 210.5
16 15.7 56 52.4 96 115.9 136 216.6
18 17.1 58 54.9 98 120.0 138 222.8
20 18.4 60 57.4 100 124.1 140 229.2
22 19.9 62 60.0 102 128.4 142 235.6
24 21.3 64 62.7 104 132.7 144 242.2
26 22.9 66 65.4 106 137.2 146 249.0
28 24.5 68 68.2 108 141.7 148 255.8
30 26.1 70 71.1 110 146.3 150 262.8
32 27.8 72 74.0 112 151.1 152 270.0
34 29.5 74 77.1 114 155.9 154 277.3
36 31.3 76 80.2 116 160.9 156 284.7
38 33.1 78 83.4 118 166.0 158 292.2
40 35.0 80 86.7 120 171.1 160 299.9
42 37.0 82 90.0 122 176.4 162 307.8
44 39.0 84 93.5 124 181.8 164 315.8

Routine Maintenance

Due to the frictionless design, no yearly oil sampling or oil system maintenance is required. See maintenance Schedule
on page 58.

Refrigerant Cycle

Maintenance of the refrigerant cycle includes maintaining a log of the operating conditions, and checking that the unit
has the proper refrigerant charge.

At every inspection suction, and discharge pressures should be noted and recorded, as well as condenser and chiller
water temperatures.

The suction line temperature at the compressor should be taken at least once a month. Subtracting the saturated
temperature equivalent of the suction pressure from this will give the suction superheat. Extreme changes in sub­cooling and/or superheat over a period of time will indicate losses of refrigerant or possible deterioration or
malfunction of the expansion valves. Proper superheat setting is 1- 3 degrees F at full load. Such a small temperature
difference can be difficult to measure accurately. Another method is to measure the compressor discharge superheat,
the difference between the actual discharge temperature and the saturated discharge temperature. The discharge
superheat should be between 10 and 14 degrees F at full load. The liquid injection must be deactivated (by closing the
valve in the feed line) when taking the discharge temperature. The superheat will increase linearly to 55 degrees F (30
degrees C) at 10% load. The MicroTech E interface panel can display all superheat and sub-cooling temperatures.

52 OMM 1034-2

Figure 8, Typical Refrigerant Flow Diagram

NOTE: All valves indicated with reference numbers should be open for chiller operation.

OMM 1034-2 53

!

CAUTION

Electrical System

1. Maintenance of the electrical system involves the general requirement of keeping contacts clean and

connections tight and checking on specific items as follows:

2. The compressor current draw should be checked and compared to nameplate RLA value. Normally, the actual

current will be lower, since the nameplate rating represents full load operation. Also check all pump and fan
motor amperages, and compare with nameplate ratings.

3. At least once a quarter, all equipment protection controls except compressor overloads should be made to

operate and their operating points checked. A control can shift its operating point as it ages, and this must be
detected so the controls can be adjusted or replaced. Pump interlocks and flow switches should be checked to
be sure they interrupt the control circuit when tripped.

4. Tighten all power terminal connections in the VFD quarterly.

5. The compressor motor resistance to ground should be checked and logged semi-annually. This log will track

insulation deterioration. A reading of 50 megohms or less indicates a possible insulation defect or moisture
and must be further checked.

Never Megger a motor while in a vacuum. Severe motor damage can result.

6. The centrifugal compressor must rotate clockwise, as view from the suction side of the compressor. This can

be determined by looking in the sight glass mounted on the side of the compressor. In this sight glass, the
rotation will result in a downward movement. If the operator has any reason to suspect that the power
system connections have been altered, (phases reversed) the compressor must be jogged to check rotation.
For assistance, call your local McQuay Factory Service location.

Cleaning and Preserving

A common cause of service calls and equipment malfunction is dirt. This can be prevented with normal
maintenance. The system components most subject to dirt are:

1) Permanent or cleanable filters in the air handling equipment must be cleaned in accordance with the

manufacturer’s instructions; throwaway filters should be replaced. The frequency of this service will vary
with each installation.

2) Remove and clean strainers in chilled water system and condenser water system at every inspection.

3) Inspect the condenser tubes annually for fouling and clean if required. The dished water heads (aka end-
bells, water boxes) should be removed with care due to their weight. One method follows:

• After draining water, remove all but four head bolts at roughly 10 and 2 o’clock and 4 and 8 o’clock.

• Loosen these remaining four bolts to enable the head to be separated from the tube sheet sufficiently for

a clevis pin or hook to be inserted into an open bolt hole at the top of the head.

• Attach a hoist to the pin or hook, lift the head to remove weight from the remaining bolts, remove the

bolts and carefully remove the head.

• Do not try to install an eyebolt with machine threads into the head vent fitting, which has pipe threads.

• Reverse this procedure to mount the head, using a new gasket.

54 OMM 1034-2

Seasonal Servicing

Prior to shutdown periods and before starting up again, the following service procedures must be completed.

Annual Shutdown

Where the chiller can be subject to freezing temperatures, the condenser and chiller must be drained of all water. Dry
air blown through the condenser will aid in forcing all water out. Removal of condenser heads is also recommended.
The condenser and evaporator are not self-draining and tubes must be blown out. Water permitted to remain in the
piping and vessels can rupture these parts if subjected to freezing temperature.

Forced circulation of antifreeze through the water circuits is one method of avoiding freeze up.

1) Take measures to prevent the shutoff valve in the water supply line from being accidentally turned on.

2) If a cooling tower is used, and if the water pump will be exposed to freezing temperatures, be sure to remove

the pump drain plug and leave it out so any water that can accumulate will drain away.

3) Open the compressor disconnect switch. Set the manual UNIT ON/OFF switch in the Unit Control Panel to

the OFF position.

4) Check for corrosion and clean and paint rusted surfaces.

5) Clean and flush water tower for all units operating on a water tower. Make sure tower blowdown or bleed-off

is operating. Set up and use a good maintenance program to prevent “liming up” of both tower and condenser.
It should be recognized that atmospheric air contains many contaminants that increase the need for proper
water treatment. The use of untreated water can result in corrosion, erosion, sliming, scaling or algae
formation. It is recommended that the service of a reliable water treatment company be used. McQuay
International assumes no responsibility for the results of untreated or improperly treated water.

6) Remove condenser heads at least once a year to inspect the condenser tubes and clean if required.

Annual Startup

A dangerous condition can exist if power is applied to a faulty compressor motor starter that has been burned out. This
condition can exist without the knowledge of the person starting the equipment.

This is a good time to check all the motor winding resistance to ground. Semi-annual checking and recording of this
resistance will provide a record of any deterioration of the winding insulation. All new units have well over 100
megohms resistance between any motor terminal and ground.

Whenever great discrepancies in readings occur, or uniform readings of less than 50 megohms are obtained, the motor
cover must be removed for inspection of the winding prior to starting the unit. Uniform readings of less than 5
megohms indicate motor failure is imminent and the motor should be replaced or repaired. Repair before failure occurs
can save a great deal of time and labor spent in the cleanup of a system after a motor burnout.

1) Check and tighten all electrical connections.

2) Replace the drain plug in the cooling tower pump if it was removed at shutdown time the previous season.

3) Reconnect water lines and turn on supply water. Flush condenser and check for leaks.

Repair of System

Pressure Relief Valve Replacement

Current condenser designs use two relief valves separated by a three-way shutoff valve (one set). This three-way valve
allows either relief valve to be shut off, but at no time can both be shut off. In the event one of the relief valves are
leaking in the two valve set, these procedures must be followed:

• If the valve closest to the valve stem is leaking, back seat the three-way valve all the way, closing the port to the

leaking pressure relief valve. Remove and replace the faulty relief valve. The three-way shutoff valve must
remain either fully back seated or fully forward to normal operation. If the relief valve farthest from the valve
stem is leaking, front seat the three-way valve and replace the relief valve as stated above.

OMM 1034-2 55

!

DANGER

• The refrigerant must be pumped down into the condenser before the evaporator relief valve can be removed.

Pumping Down

If it becomes necessary to pump the system down, extreme care must be used to avoid damage to the evaporator from
freezing. Always make sure that full water flow is maintained through the chiller and condenser while pumping down.
To pump the system down, close all liquid line valves. With all liquid line valves closed and water flowing, start the
compressor. Pump the unit down until the MicroTech E controller cuts out at approximately 20 psig. It is possible that
the unit might experience a mild surge condition prior to cutout. If this should occur, immediately shut off the
compressor. Use a portable condensing unit to complete the pump down, condense the refrigerant, and pump it into the
condenser or pumpout vessel using approved procedures.

A pressure regulating valve must always be used on the drum being used to build the system pressure. Also, do not
exceed the test pressure given above. When the test pressure is reached disconnect the gas cylinder.

Pressure Testing

No pressure testing is necessary unless some damage was incurred during shipment. Damage can be determined upon a
visual inspection of the exterior piping, checking that no breakage occurred or fittings loosened. Service gauges should
show a positive pressure. If no pressure is evident on the gauges, a leak may have occurred, discharging the entire
refrigerant charge. In this case, the unit must be leak tested to determine the location of the leak.

Leak Testing

In the case of loss of the entire refrigerant charge, the unit must be checked for leaks prior to charging the complete
system. This can be done by charging enough refrigerant into the system to build the pressure up to approximately 10
psig (69 kPa) and adding sufficient dry nitrogen to bring the pressure up to a maximum of 125 psig (860 kPa). Leak test
with an electronic leak detector. Halide leak detectors do not function with HFC-134a. Water flow through the vessels
must be maintained anytime refrigerant is added or removed from the system.

Do not use oxygen or a mixture of R-22 and air to build up pressure, as an explosion can occur which will cause serious

personal injury or death.

If any leaks are found in welded or brazed joints, or it is necessary to replace a gasket, relieve the test pressure in the
system before proceeding. Brazing is required for copper joints.

After making any necessary repair, the system must be evacuated as described in the following section.

Evacuation

After it has been determined that there are no refrigerant leaks, the system must be evacuated using a vacuum pump
with a capacity that will reduce the vacuum to at least 1000 microns of mercury.

A mercury manometer, or an electronic or other type of micron gauge, must be connected at the farthest point from the
vacuum pump. For readings below 1000 microns, an electronic or other micron gauge must be used.

The triple evacuation method is recommended and is particularly helpful if the vacuum pump is unable to obtain the
desired 1 millimeter of vacuum. The system is first evacuated to approximately 29 inches of mercury. Dry nitrogen is
then added to the system to bring the pressure up to zero pounds.

Then the system is once again evacuated to approximately 29 inches of mercury. This is repeated three times. The first
pull-down will remove about 90% of the non-condensables, the second about 90% of that remaining from the first
pull-down and, after the third, only 1/10-1% non-condensables will remain.

Charging the System

Model WME water chillers are leak tested at the factory and shipped with the correct charge of refrigerant as indicated
on the unit nameplate. In the event the refrigerant charge was lost due to shipping damage, the system should be
charged as follows after first repairing the leaks and evacuating the system.

1) Connect the refrigerant drum to the gauge port on the liquid line shutoff valve and purge the charging line
between the refrigerant cylinder and the valve. Then open the valve to the mid-position.

56 OMM 1034-2

2) Turn on the cooling tower water pump and chilled water pump and allow water to circulate through the

condenser and the chiller. (It will be necessary to manually close the condenser pump starter.)

3) If the system is under a vacuum, stand the refrigerant drum with the connection up, and open the drum and

break the vacuum with refrigerant gas to a saturated pressure above freezing.

4) With a system gas pressure higher than the equivalent of a freezing temperature, invert the charging cylinder

and elevate the drum above the condenser. With the drum in this position, valves open, water pumps operating,
liquid refrigerant will flow into the condenser. Approximately 75% of the total requirement estimated for the
unit can be charged in this manner.

5) After 75% of the required charge has entered the condenser, reconnect the refrigerant drum and charging line

to the service valve on the bottom of the evaporator. Again purge the connecting line, stand the drum with the
connection up, and place the service valve in the open position.

IMPORTANT: At this point, the charging procedure should be interrupted and prestart checks made bef ore
attempting to complete refrigerant charge. The compr ess or must not be started at this time. ( Preliminar y
check must first be com plet ed. )

NOTE: It is of utmost importance that all local, national, and international regulations concerning the
handling and emission of refrig er ants ar e observed.

OMM 1034-2 57

I. Unit

· Operational Log

O

· Analyze Operational Log

O

· Refrigerant Leak Test Chiller

O

· Test Relief Valves or Replace

X

II. Compressor

· Vibration Test Compressor

X

A. Motor

· Meg. Windings

X

· Ampere Balance (within 10% at RLA )

O

· Terminal Check (Inf rared t emperature measurement)

X

· Motor Cooling Filter Drier Pressure Drop

X

- Motor Winding resis t ance ( milli-ohm)

X

- Bearing Coil Winding resistance ( milli-ohm)

X

III. Controls

A. Operating Controls

· Calibrate Temperature Sensors/Transducers

X

· Calibrate Pressure Transducers

X

· Check Vane Control Setti ng and Operation

X

· Verify Motor Load Limit Control

X

· Verify Load Balance Operation

X

B. Protective Controls

· Test Operation of:

Alarm Relay

X

Pump Interlocks

X

High and Low Pressure Cutouts

X

IV. Condenser

A. Evaluation of Tem p Approach (NOTE 1)

O

B. Test Water Quality

V

C. Clean Condenser Tubes (NOTE 3)

X X

D. Eddy current Test - Tube Wall Thickness

V

E. Seasonal Protect i on

X

V. Evaporator

A. Evaluation of Tem p Approach (NOTE 1)

O

B. Test Water Quality

V

C. Clean Evaporator Tubes (NOTE 3)

X

D. Eddy current Test - Tube Wall thickness

V X

E. Seasonal Protect i on

X

VI. Expansion Valves

A.Operational Evaluation (Superheat Control)

X

VII. Starter(s)

A. Examine Contactors (hardware and operation)

X

B. Verify Overload Setting and T ri p

X

C. Test Electrical Connections (Infrared tem p measurement)

X

KEY:

O = Performed by in-house personnel.

X = Performed by McQuay authorized service personnel. (NOTE 4)

V = Normally performed by third parties.

Maintenance Sch edule

Maintenance Check List Item

Daily

Weekly

Monthly

Quarterly

Annually

5-Yr

As Req’d

58 OMM 1034-2

NOTES:

1) Approach temperature (the difference between the leaving water temperature and the saturated refrigerant temperature) of either

the condenser or evaporator is a good indication of tube fouling, particularly in the condense r, where constant flow usually
prevails. McQuay's high efficiency heat exchangers have very low design approach temperatures, in the order of one to one and
one-half degrees F.

2) The chiller unit controller can displa y the water and the saturated refrigerant temperatures. Simple subtraction will give the

approach. It is recommended that benchmark readings (including condenser pressure drop to confirm future flow rates) be taken
during startup and then periodically afterward. An approach increase of two-degrees or more would indicate that excessive tube
fouling could be present. Higher than normal discharge pressure and motor current are also good indicators

3) Evaporators in closed fluid circ uits with treated water or anti-freeze are no t no r mally subject to fouling, hover it is prude nt to

check the approach periodically.

4) Performed when contracted for, not part of standard initial warranty service.

OMM 1034-2 59

Service Programs

It is important that an air conditioning system receive adequate maintenance if the full equipment life and full system
benefits are to be realized.

Maintenance should be an ongoing program from the time the system is initially started. A full inspection should be
made after 3 to 4 weeks of normal operation on a new installation, and on a regular basis thereafter.

McQuay International offers a variety of maintenance services through the local McQuay Factory Service office, its
worldwide service organization, and can tailor these services to suit the needs of the building owner. Most popular
among these services is the McQuay Comprehensive Maintenance Contract.

For further information concerning the many services available, contact your local McQuay Factory Service office.

Operator Training

Training courses for Centrifugal Maintenance and Operation are held through the year at the Daikin McQuay Training
Center in Staunton, Virginia. The school duration is three and one-half days and includes instruction on basic
refrigeration, MicroTech controllers, enhancing chiller efficiency and reliability, MicroTech troubleshooting, system
components, and other related subjects. Further information can be found on
International at 540-248-0711 to speak to the Training Department.

www.daikinmcquay.com

or call McQuay

Warranty Statement

Limited Warranty

All Daikin McQuay equipment is sold pursuant to McQuay International’s Standard Terms and Conditions of
Sale and Limited Product Warranty. Consult your local Daikin McQuay Representative for warranty details.
Refer to form 933-430285Y. To find your local representative, go to

www.daikinmcquay.com.

60 OMM 1034-2

[phone] • www.daikinmcquay.com OMM 1034-2 (7/12)

Daikin McQuay Training and Development

Now that you have made an investment in modern, efficient Daikin McQuay equipment , its car e should be a
high priority. For training information on all Daikin McQuay HVAC products, please visit us at
www.daikinmcquay.com and click on training, or call 540-248-9646 to speak to the Training Department.

Warranty

All Daikin McQuay equipment is sold pursuant t o McQuay International’s Standard Terms and Conditions of
Sale and Limited Product Warranty. Consult your local Daikin McQuay Representat ive for warranty details.
Refer to form 933-430285Y. To find your local representative, go to www.daikinmcquay.com

This document contains the most current product information as of this printing. For the most up-to-date
product information, please g o t o

www.daikinmcquay.com.

[phone] • www.daikinmcquay.com OMM 1034-2 (7/12)