McQuay VFD 019 Installation Manual
Installation, Operation and Maintenance Manual
Variable Frequency Drive
For Centrifugal Chillers
MicroTech 200
MicroTech II
IOMM VFD
Group: Chiller
Part Number: 736015429
Effective: January 2003
Supercedes: New
Table of Contents
g
Introduction............................................................................................................4
General Description...............................................................................................5
Codes/Standards............................................................................................................................5
Quality Assurance.........................................................................................................................5
Nomenclature................................................................................................................................5
Definition of Terms ................................................................................................7
Parameters.....................................................................................................................................8
Service Conditions........................................................................................................................8
Standard Features..........................................................................................................................8
Cooling Requirements for VFDs ..........................................................................9
VFD Dimensional Diagrams...............................................................................11
MicroTech 200 VFD Control...........................................................................15
VFD Chiller Control States.........................................................................................................15
Control Sequence, MicroTech 200......................................................................16
WDC, Dual Compressor VFD Operation....................................................................................17
MicroTech 200 Controller VFD Menu Screens..........................................................................17
MicroTech II VFD Control..............................................................................23
General Description:...................................................................................................................23
Sequence of Operation................................................................................................................24
Interface Panel Screens...............................................................................................................25
VFD Components and Locations .......................................................................29
Regulator Board Description.......................................................................................................32
Using the VFD Keypad/Display..........................................................................33
Monitor Mode.............................................................................................................................34
The Display.................................................................................................................................35
The Keypad.................................................................................................................................36
Drive Status LEDs.......................................................................................................................38
Optional Line Reactors .......................................................................................39
Troubleshooting the Drive Using Error Codes..................................................40
Identifying Alarm Codes and Recovering...................................................................................41
Identifying Fault Codes and Recovering.....................................................................................42
Accessing, Reading, and Clearing the Faults in the Error Log ....................................................45
“McQuay" is a registered trademark of McQuay International
"Information and illustrations cover the McQuay International products at the time of publication and we reserve the right to make changes
in desi
2 IOMM VFD
2003 McQuay International
n and construction at anytime without notice".
DANGER
Only qualified electrical personnel familiar with the construction and operation of this
equipment and the hazards involved should install, adjust, operate, or service this
equipment. Read and understand this manual and other applicable manuals in their
entirety before proceeding. Failure to observe this precaution could result in severe bodily
injury or loss of life.
DANGER
DC bus capacitors retain hazardous voltages after power has been disconnected. After
disconnecting input power to the unit, wait five (5) minutes for the DC bus capacitors to
discharge, and then check the voltage with a voltmeter to ensure the DC capacitors are
discharged before touching any internal components. Failure to observe this precaution
could result in severe bodily injury or loss of life.
CAUTION
The user is responsible for conforming to all applicable local, national and international
codes. Failure to observe this precaution could result in damage to,
or destruction of the equipment.
WARNING
The drive contains printed circuit boards that are static-sensitive. Anyone who touches the
drive components should wear an anti-static wristband. Erratic machine operation and
damage to, or destruction of, equipment can result if this procedure is not followed.
Failure to observe this precaution can result in bodily injury.
IOMM VFD 3
Introduction
WSC and WDC single and dual compressor chillers can be equipped with a Variable Frequency Drive
(VFD). A VFD modulates the compressor speed in response to load, evaporator pressure, and condenser
pressure, as sensed by the chiller microprocessor. Despite the small power penalty attributed to the
VFD, the chiller can achieve outstanding overall efficiency. VFDs are effective when there is a reduced
load, combined with a low compressor lift (lower condenser water temperatures), dominating the
operating hours.
The traditional method of controlling centrifugal compressor capacity is by inlet guide vanes. Capacity
can also be reduced by slowing down the compressor, thereby reducing the impeller tip speed.
However, sufficient impeller tip speed must always be maintained to meet the chiller’s discharge
pressure requirements. The speed control method is more efficient than guide vanes by themselves.
In actual practice, a combination of the two techniques is used. The microprocessor slows the
compressor (to a programmed minimum percent of full load speed) as much as possible, considering the
need for tip speed to make the required compressor lift. Then the guide vanes take over for further
capacity reduction. This methodology provides the optimum efficiency under any operating condition.
Inlet guide vanes control compressor capacity based on a signal from the microprocessor, which is
sensing changes in the leaving chilled water temperature. The guide vanes vary capacity by changing
the angle and flow of the suction gas entering the impeller. The impeller takes a smaller “bite” of the
gas. Reduced gas flow results in less capacity. Compressors start unloaded (guide vanes closed) in
order to reduce the starting effort. A vane-closed switch (VC) signals the microprocessor that the
compressor vanes are closed.
VFDs can be found on centrifugal chillers with the older MicroTech 200 controller (sometimes referred
to as MicroTech I or just plain MicroTech) or the newer MicroTech II controller. The two MicroTech
controller versions are easily differentiated as shown below.
MicroTech 200 Control Panel
MicroTech II Operator Interface
Panel
Operation and adjustment of the VFD involves settings on both the VFD itself and also to the chiller
controller, either MicroTech 200 controller or MicroTech II controller. This manual consists of a section
relating to VFD operation common to both chiller controllers and also separate sections for the settings
specific to either of the chiller MicroTech controllers.
NOTE: VFDs are programmed differently in the factory for 50 and 60 hertz applications. It is prudent
to verify this by checking the settings sticker in the unit and the actual unit settings using the Reliance
manual shipped with the VFD unit as a reference.
4 IOMM VFD
General Description
The VFD will not generate damaging voltage pulses at the motor terminals when applied within 500 feet
of each other. The VFD drive complies with NEMA MG1 section 30.40.4.2, which specifies these
limits at a maximum peak voltage of 600 volts and a minimum rise time of 0.1 microseconds.
All VFDs require cooling. Models VFD 019 and VFD 025, which draw 240 amps or less, are aircooled. All others are water-cooled.
Factory-mounted water-cooled units have cooling water for the VFD combined with the compressor oil
cooling system.
Freestanding water-cooled units require field-installed chilled water supply and return piping for the
VFD.
Water-cooled VFD’s have a liquid-cooled heatsink assembly enabling liquid cooling of the drive though
a single inlet and outlet connection point, dissipating 25,000 Btus/Hr for 600HP, 20,000 Btus/Hr for 450
HP and 16,000 Btus/Hr for 350 HP. The cooling circuit maintains water temperature between 60°F and
104°F (15°C to 40°C).
There is a temperature-regulating valve located in the drive. It must be set to maintain 95°F (35°C)
leaving coolant temperature. This is necessary to prevent condensation from forming in the heatsink.
Codes/Standards
• VFDs are UL 508 listed
• VFDs are designed to comply with the applicable requirements of the latest standards of ANSI,
NEMA, National Electric Code (NEC), NEPU-70, IEEE 519-1992, FCC Part 15 Subpart J, CE 96.
Quality A ssurance
• Every VFD is functionally tested under motor load. During this test the VFD is monitored for
correct phase current, phase voltages, and motor speed. Correct current limit operation is verified
by simulating a motor overload.
• Scrolling through all parameters verifies proper factory presets. The computer port also verifies that
the proper factory settings are loaded into the drive.
• Every VFD’s heatsink is tested to verify proper embedding of the tubing for flow of coolant liquid.
Thermal tests are performed on the VFD to verify that the cooling occurs within the correct
temperature range.
Nomenclature
VFD XXX X X
Model Number
019 through 120
Mounting
M=Factory-mounted
L= Shipped Loose for Field Mounting
Cooling Method
A=Air-cooled
W=Water-cooled
IOMM VFD 5
Figure 1, VFD Internal Components, Factory Mount ed, Water-Cooled M odel
Motor Terminals
Disconnect Switch
Optional Meter
Transformers (2)
Terminal Board
Fuses
Motor Control
Relays (MCR)
Control
Transformer
w/ Fuses
Table 1, VFD Model Sizes
VFD Model Max. Amps Power Cooling
VFD 019 170 3/60/460-480 Air
VFD 025 240 3/60/460-480 Air
VFD 047 414 3/60/460-480 Water
VFD 060 500 3/60/460-480 Water
VFD 072 643 3/60/460-480 Water
VFD 090 890 3/60/460-480 Water
VFD120 1157 3/60/460-480 Water
Drive Unit
Keyboard/Display
Cooling W ater
Lines
6 IOMM VFD
Definition of Terms
Active LEWT Setpoint
Command Speed
Demand Limit
FVC
IGBT
Lift Temperature
Lift Temperature Control
Speed
Low evap pressure
inhibit setpoint
Manual Load Setpoint
Maximum Pulldown
Rate
MCR
Minimum Amp Setpoint
Minimum Rate Setpoint
Minimum Speed
Network Capacity Limit
Maximum capacity
allowed from an external
signal
Network Setpoint
OIM
PCB
PWM
Rapid Shutdown
RLA
RMI
Softloading
Speed
Stage Delta
SVC
the current Leaving Evaporator Water Temperature Setpoint
the speed command issued by the MicroTech controller to the VFD
the maximum amp draw as established by the Demand Limit setpoint
flux vector control
Insulated Gate Bi-polar Transistors
Saturated condenser refrigerant temperature minus saturated evaporator
temperature.
The minimum speed to maintain lift and avoid surge. The controller
continuously calculates the minimum operating speed in all modes, based
on the lift temperature.
the low evaporator pressure that inhibits any further compressor loading
MicroTech controller manual operation of the guide vanes for testing
maximum pulldown rate of chilled water in degrees per minute
motor control relay
MicroTech controller minimum unloading setpoint
pulldown rate for MicroTech 200 controller
the minimum speed allowed, usually set at 70%
chilled water setpoint from an external source
operator interface module
printed circuit board
pulse-width-modulated
if there is a fault, the MicroTech switches the state to VFD OFF. This
includes changing the Unit Control Panel switch to OFF.
, Rated Load Amps, the maximum motor amps
remote meter interface, located in the VFD panel
extended ramp-up in capacity, set in the MicroTech controller
speed signal to the compressor motor from the variable frequency drive
(VFD) based on analog output (0 – 10 VDC) from the MicroTech controller.
multi compressor (or dual compressor unit) on/off cycling temperature
delta-T
sensorless vector control
IOMM VFD 7
Parameters
Throughout this manual, you will see references to parameter names and numbers that identify them for
the drive. This manual uses the same format that will be shown on the keypad/display to refer to
parameters:
P.nnn H.nnn R.nnn
Where: nnn is a number
P designates general parameters
H designates Volts/Hertz parameters
R designates optional RMI parameters
CAUTION
These parameters must never be changed from the startup values set by the McQuay
startup technician. Damage to the chiller or drive could occur.
Service Conditions
Input power: 380/460 VAC ±10%, 3 phase, 50/60 Hertz, ±5 Hz.
Ambient operating temperature range: 32°F to 104°F (0°C to 40°C), elevation up to 3300 feet (1000m)
altitude with a relative humidity to 95% non-condensing.
Storage temperature range: 50°F to 122°F (10°C to 50°C).
AC line distribution system capacity shall not exceed 85,000 amps symmetrical available fault current.
Standard Features
• Electronic overload circuit designed to protect an AC motor, operated by the VFD output, from
extended overload operation on an inverse time basis. This electronic overload is UL and NEC
recognized as adequate motor protection. No additional hardware, such as motor overload relays, or
motor thermostats are required.
• An LED display that digitally indicates:
Frequency output Input kW
Voltage output Elapsed time
Current output Time stamped fault indication
Motor RPM DC bus voltage
• The VFD is capable of maintaining operation through power dips up to 10 seconds without a
controller trip, depending upon load and operating conditions. In this extended ride-through, the
drive uses the energy generated by the load inertia of the motor as a power source for electronic
circuits.
• An isolated 0-20mA, 4-20mA, or 0-4, 0-8, 0-10 V analog speed input follower.
• An isolated 0-10V or 4-20mA output signal proportional to speed or load.
8 IOMM VFD
• Standard I/O expansion interface card with the following features:
• Four isolated 24VDC programmable digital inputs
• One frequency input (0 to 200Hz) for digital control of speed or trim reference
• Four programmable isolated digital outputs (24 VDC rated)
• One Form A output relay rated at 250 VAC or 24VDC
• Two NO/NC programmable output relays rated at 250 VAC or 24 VDC
• The VFD includes the following standard protective circuit features:
• Output phase-to-phase short circuit condition
• Total ground fault under any operating condition
• High input line voltage
• Low input line voltage
• Loss of input or output phase
• External fault (This protective circuit will permit wiring to a remote normally closed equipment
protection contact to shut down the drive.)
• Metal oxide varistors for surge suppression are provided at the VFD input terminals.
Cooling Requirements for VFDs
VFD cooling water piping is factory-connected to the chiller’s oil cooling system on factory-mounted VFDs.
See Figure 2.
VFD cooling water piping must be field connected on freestanding VFDs. See Figure 3.
Figure 2, VFD (047 through 120) Cooling Water Piping for Factory-M ount ed VFD
*
STOP
*
CHILLED
WATER
PUMP
VALV E
*
STOP
VALVE
Field Supplied Piping Components
*
Field Piping
Connection Point
BALANCING
VALV E
*
STRAINER
MAX. 40 MESH
CHILLER
VFD HEAT
EXCHANGER
SOLENOID
VALV E
(Factory Mounted)
SOLENOID
VALV E
(Factory Mounted)
*
DRAIN VALVE
OR PLUG
COMPRESSOR
OIL COOLER CIRCUIT
WATER
REGULATING
VALVE
(Factory Mounted)
*
STOP
VALV E
WATER
REGULATING
VALV E
(Factory Mounted)
*
STOP
VALVE
See notes on next page.
IOMM VFD 9
Figure 3, VFD (047 and Larger) Cooling Water Piping for Free-Standing VFD
*
CHILLED
WATER
PUMP
STOP
VALVE
*
STOP
VALVE
Field Supplied Piping Components
*
Field Piping
Connection Point
*
BALANCING
VALVE
*
STRAINER
MAX. 40 MESH
CHILLER
VFD HEAT
EXCHANGER
SOLENOID
VALV E
(Factory Mounted)
SOLENOID
VALV E
(Factory Mounted)
*
DRAIN VALVE
OR PLUG
COMPRESSOR
OIL COOLER CIRCUIT
WATER
REGULATING
VALV E
(Factory Mounted)
REGULATING
(Factory Mounted)
*
STOP
VALVE
WATER
VALVE
*
STOP
VALVE
Table 2, Cooling Requirements
McQuay
Drive Model
Number
Combined
Compressor Oil
and VFD Cooling
Copper Tube Size
Type K or L
VFD Cooling
Only Copper
Tube Size
Type K or L
Coolant
Method
Max.
Entering
Coolant
Temperature
(°°°° F)
VFD 019 N/A N/A Air 104 40 NA N/A
VFD 025 N/A N/A Air 104 40 NA N/A
VFD 047 1.0 7/8 in. Water (1) 90 40 10 (2) 300
VFD 060 1.0 7/8 in. Water (1) 90 40 30 (2) 300
VFD 072 1.0 7/8 in. Water (1) 90 40 30 (2) 300
VFD 090 1 1/4 1.0 in. Water (1) (3) 90 40 30 (2) 300
VFD 120 1 1/4 1.0 in. Water (1) (3) 90 40 30 (2) 300
Notes:
1. Cooling water must be from the closed, chilled water circuit with corrosion inhibitors for steel and copper, and must be piped across the
chilled water pump.
2. The required pressure drop is given for the maximum coolant temperature. The water regulating valve will reduce the flow when the
coolant temperature is below the maximum in the table. The pressure drop includes the drop across the solenoid valve, heat exchanger
and water regulating valve.
3. Models VFD 090and 120 have a separate self-contained cooling loop with a recirculating water pump and heat exchanger, but are piped
the same as all water-cooled VFDs.
Min.
Entering
Coolant
Temperature
(°°°° F)
Required
Pressure
Drop
feet
Maximum
Pressure
(Water Side)
psi
Table 3, Cooling Water Connection Sizes
Chiller Unit
Oil Cooler VFD Combined
WDC 100/126 1 1/2 in. FPT ¾ in. MPT 1 1/2 in. FPT
WSC/WDC 050 Not Required Air-Cooled Not Required
All Others 1 in. FPT 3/4 in MPT 1 in. FPT
Free-Standing VFD Factory-Mounted VFD
10 IOMM VFD
VFD Dimensional Diagrams
m
Figure 4, VFD 019/025 (Air-Cooled)
8.0
(203.2)
Power Wiring
Entry Panel
6.0
(152.4)
2.0
(50.8)
14.0
(355.6)
Removable
Lifting Eyes
Note: Remove before drilling
to prevent metal particles fro
falling into drive components.
72.0
(1828.8)
VM
AM
36.0 (914.4)
19.1 (485.1)
IOMM VFD 11
Figure 5, VFD 047 (Water-Cooled)
T
8.00
8.00
21.06
(534.92)
2.00 (50.8)
16.00
(406.4)
6.00
(152.4)
(203.2)
POWER WIRING
(203.2)
ACCESS PANEL
POWER WIRING
ACCESS PANEL
6.00
(152.4)
2.00 (50.8)
16.00
(406.4)
Removable
Lifting Eyes
Note: Remove before drilling
to prevent metal particles from
falling into drive components.
20.00
(508.0)
36.00
(914.4)
90.00
(228.6)
3.00
(76.2)
OUTLET
INLET
7.13
(181.1)
BOTH INLET AND OUTLET ARE 3/4 (19.1) NP
2.61 (66.3)
12 IOMM VFD
Figure 6, VFD 060/072 (Water-Cooled)
12.0
6.0
(
)
3.0 (76.2)
12.0
(304.8)
(152.4)
(304.8)
POWER WIRING
ACCESS PANEL
12.0
(304.8)
POWER WIRING
ACCESS PANEL
60.0
(1524)
15.0
(381)
9.0
(228.6)
3.0 (76.2)
12.0
(304.8)
72.0
(1828.8)
Note: Remove before drilling
to prevent metal particles from
falling into drive components.
19.1
(485.1)
OUTLET VALVE
3/4 (19.1) NPT
INLET VALVE
3/4 (19.1) NPT
18.6
(473.2)
3.5
(88.9)
7.5
190.5
IOMM VFD 13
Figure 7, VFD 090/120 (Water-Cooled)
/
/
A
A
3.38
(85.8)
TYP
16.0
(406.4)
10.5
(266.7)
11. 9
(302.3)
24.3
(617.2)
11. 9
(302.3)
Note: Remove before drilling
to prevent metal particles from
falling into drive components.
POWER
ON
W
DRIVE
ULT
F
PUMP
MOTOR
RUNNING
B
(1828.8)
FAN
AIR
FLOW
72.0
LINE LEAD ACCESS
COVER PLATE
78.2
(1986.3)
MOTOR LEAD ACCESS
COVER PLATE
POWER
ON
W
DRIVE
FAULT
A
PUMP MOTOR
RUNNING
B
CLOSED LOOP
COOLING SYSTEM
32.4
(822.9)
34.1
(866.1)
WATER
RESERVOIR
CUSTOMER
OUTLET
INLET
3
4 " (19.1) NPT
19.6
(497.8)
15.6
(396.2)
31.6
(802.6)
24.2
(614.7)
OUTLET
INLET
11. 4
(289.6)
14 IOMM VFD
MicroTech 200 VFD Co ntrol
The MicroTech 200 unit controller is wired to the variable frequency drive instead of to a motor starter.
The MicroTech controller provides the speed setpoint signal to a hardwired input on the VFD. The
output on the MicroTech AOX (auxiliary output) board is configured (using jumpers) to provide a 0-10
VDC signal to a hard wired analog input on a VFD.
There is no feedback signal required from the variable frequency drive to the MicroTech to indicate the
speed of the motor. The actual percent motor speed is within 1% of the analog output signal from the
MicroTech controller.
Digital Input, DI 10, is wired to a switch on the compressor that indicates when the vanes are 100%
open (VO switch). If the switch is open, the status of the vanes is Not Open. If the switch is closed, the
status of the vanes is Open.
VFD Chiller Control States
There are seven (7) VFD chiller control states and they are based on the unit status. See Table 5 on page
19 for relationships.
MicroTech: Menu 1, Screen 2
MicroTech 200
VFD Off
VFD Start
VFD Running: Adjust Speed & Open Vanes
VFD Running: Hold Mi nimum Speed & Adjust
Vanes
VFD Routine Shutdown
VFD Locked Speed
VFD Override Capacity Control
VFD Off: The VFD is turned off, the speed output is 0%, and the vanes are closed.
VFD Start: The VFD is turned on, the speed output is minimum speed, and the vanes are modulated to
maintain the leaving evaporator setpoint. (VFD running, hold minimum speed, and adjust vanes mode.)
VFD Running Adjust Speed & Open Vanes: The VFD remains on, the speed output is modulated to
maintain the leaving evaporator setpoint, and the vanes are pulsed to the open position. This mode
drives the vanes open and uses the speed to control capacity based on the evaporator leaving water
setpoint.
VFD Running Hold Minimum Speed & Adjust Vanes: The VFD remains on, the speed output is held
at Minimum Speed, and the vanes are modulated to maintain the evaporator leaving water setpoint. This
mode occurs when the load (tons) can be satisfied with the vanes not fully open while at minimum
speed. Decreasing speed can no longer reduce capacity, so the vanes maintain temperature control.
When the load increases, the vanes will pulse open until the vane open switch shows that the vanes are
full open. At this point, the MicroTech controller changes the mode to VFD Running: Adjust Speed and
Open Vanes.
VFD Routine Shutdown: The VFD remains on, the speed output remains the same, dependent on the
prior state, and the vanes are driven closed.
IOMM VFD 15
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