Johnson Controls VFD66 Series Manual

Product/Technical Bulletin VFD66
Issue Date November 19, 2002
© 2002 Johnson Controls, Inc. 1
Code No. LIT-125467 www.johnsoncontrols.com
Part No. 24-7664-1555, Rev. D
VFD66 Series Condenser Fan Speed Controls
The VFD66 Series Condenser Fan Speed Controls
regulate the speed of 3-phase condenser fan motors in
refrigeration and Heating, Ventilating, and Air
Conditioning (HVAC) systems by varying the
frequency and voltage of the power supplied to the
motor.
The VFD66 control accepts an input signal from the
P35 Pressure Transducer, P399 Electronic Pressure
Transducer, System 350
 pressure or temperature
controls, or any other device that provides a 0-5 VDC
or 0-10 VDC analog output signal.
The application-specific design of the VFD66 control
provides a simple interface, which makes the control
easy to understand and operate. Figure 1: VFD66 Condenser Fan Speed Control,
NEMA 4 and NEMA 1 Enclosures
Features and Benefits
❑Isolated Input Circuitry Permits application with 0-5 VDC or 0-10 VDC
controllers, sensors, transducers, and
Johnson Controls System 350 controls
❑Simultaneous Acceptance
of Two Similar Inputs Allows use on dual refrigeration circuits
cooled by a single fan
❑Compact Design Provides installation ease and flexibility
❑Three-Phase, 208/230, or
400/460 VAC Models Handle three-phase motors ranging up to
10.6 amperes at 208/230 VAC or 5.5 amperes
at 400/460 VAC
❑Few End-User Settings Provide fast and easy installation and setup

2 VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin
Application
IMPORTANT: The VFD66 Series Condenser Fan
Speed Controls are intended to control equipment
under normal operating conditions. Where failure or
malfunction of a VFD66 control could lead to an
abnormal operating condition that could cause
personal injury or damage to the equipment or other
property, other devices, (limit or safety controls) or
systems (alarm or supervisory) intended to warn of,
or protect against, failure or malfunction of the
VFD66 control must be incorporated into and
maintained as part of the control system.
The VFD66 control accepts input signals from a variety
of pressure transducers, temperature sensors, and
low-voltage controllers to provide continuous response
to changing condenser load conditions.
The VFD66 control allows the system to:
•maintain optimum condenser head pressure in low
ambient temperature conditions
•eliminate short-cycling in low ambient
temperatures or changing load conditions
•match the condenser fan speed to the load on the
condenser, which increases the efficiency of the
refrigeration system. This can reduce electricity
cost and help maintain a constant evaporator
temperature.
The VFD66 control also:
•stabilizes the condenser head pressures, which
helps optimize compressor operation and can
reduce wear and extend compressor life
•eliminates the condenser fan short-cycling, which
can reduce motor repair and replacement costs
•stabilizes evaporator temperatures, which can
extend refrigerated product life and provide more
consistent comfort cooling
Installation
Use the information in this section to install the
VFD66 control.
Dimensions
Figure 2, Figure 3, and Figure 4 show dimensions of
the enclosures used on the VFD66 controls. See
Figure 2 for information on models with NEMA 1
enclosures. See Table 1, Figure 3, and Figure 4 for
information on models with NEMA 4 enclosures.
Ter mi na l
Access
Cover
Ter mi n al
Cover
Screw
Heat
Sink
7-1/2
(190)
7
(177)
3 conduit openings
7/8-in. (22 mm) actual size
1/2-in. trade size
1/4-in. (6 mm)
mounting screws,
4 places
6-1/4
(159)
4-3/4
(120)
4-5/8
(117)
7-1/4
(184)
Diagnostic
Light-Emitting
Diodes (LEDs)
Figure 2: VFD66 NEMA 1 Enclosure Dimensions
Table 1: NEMA 4 Enclosure Size by Types/Models
NEMA 4
Enclosure Size
Models
Small VFD66AEE, VFD66BEE
Large VFD66CEE, VFD66DEE
Ter mi n al
Access
Cover Te rm i na l
Cover
Screws (4)
Diagnostic
Display
3 conduit openings
7/8-in. (22 mm) actual size
1/2-in. trade size 1/4-in. (6 mm) mounting screws,
4 places
Heat
Sink
9-1/16
(230)
4-3/4
(120)
7-7/16
(189)
4-5/8
(117)
8-13/16
(224)
8-5/16
(211)
Figure 3: Small VFD66 NEMA 4 Enclosure
Dimensions

VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin 3
Diagnostic
Display
3 conduit openings
7/8-in. (22 mm) actual size
1/2-in. trade size
1/4-in. (6 mm)
mounting screws,
4 places
Te rm in a l
Access
Cover
Ter m in a l
Cover
Screws (4)
4-3/4
(120)
9-1/16
(230)
4-5/8
(117)
7-7/16
(189)
11-5/16
(287)
11-13/16
(300)
Figure 4: Large VFD66 NEMA 4 Enclosure
Dimensions
Accessories
Table 2 lists input devices and other accessories used
with the VFD66 controls, available from
Johnson Controls/PENN.
Table 2: Pressure Transducers, Temperature Controls, and Other Accessories for VFD66 Series Controls
Product Code
Number
Description Information
P35AG-9200R Pressure Transducer
0-350 psi range
Refer to P35 Pressure Transducer and VFD66 Control
Application Note (LIT-121418) for more information.
P399AAA-1C
P399AAC-1C
Electronic Pressure Transducer,
0-100 psi range
P399GAA-1C Electronic Pressure Transducer,
0-200 psi range
P399BAA-1C
P399BAC-1C
Electronic Pressure Transducer,
0-500 psi range
P399CAA-1C
P399CAC-1C
Electronic Pressure Transducer,
0-750 psi range
P399AAA-1-200C
P399AAC-1-200C
P399BAA-1-200C
P399BAC-1-200C
P399CAA-1-200C
P399CAC-1-200C
Electronic Pressure Transducer
(as above) packaged with
WHA-P399-200C
WHA-P399-200C Wire Harness with pigtail leads,
6-1/2 ft (2 m)
WHA-P399-400C Wire Harness with pigtail leads,
13 ft (4 m)
WHA-P399-600C Wire Harness with pigtail leads,
19-5/8 ft (6 m)
Refer to P399 Series Electronic Pressure Transducers
Product/Technical Bulletin (LIT-125515) for more information.
Continued on next page . . .

4 VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin
Product Code
Number (Cont.)
Description Information
A350PS-1C Proportional Plus Integral
Temperature Control
Refer to System 350 A350P Electronic Proportional Plus Integral
Temperature Control Product/Technical Bulletin (LIT-930020) for
more information.
P352PN-3C Proportional Plus Integral
Pressure Control
Refer to System 350 P352PN Electronic Proportional Plus
Integral Pressure Controls for PSI Applications Product/Technical
Bulletin (LIT-930044) for more information.
VFD66-CVR-1C External Potentiometer
Replacement Cover
Refer to Installing the External Potentiometer Replacement Cover
Application Note (LIT-121419) for more information.
Mounting
!
CAUTION: Risk of Thermal Damage.
The VFD66 control can generate and dissipate
significant heat. Mount the control on a metal,
concrete, or cinderblock mounting surface. Mounting
the VFD66 control on surfaces made of wood or
other heat-sensitive material may result in damage
to the mounting surface.
Follow the guidelines below when mounting a
VFD66 control:
•Mount the VFD66 control on a vertical surface with
the heat sink fins oriented vertically and the
conduit holes facing down.
•Provide a minimum of 4 in. (102 mm) clearance
around the heat sink.
•Ensure that output power wiring between the
VFD66 control and the motor does not exceed
50 ft (15 m).
•Mount NEMA 1 models indoors, in a location
protected from explosive vapors, corrosive gas,
water, and dust.
•Mount NEMA 4 models indoors or outdoors in a
location protected from explosive vapors,
corrosive gas, and dust, and out of direct sunlight.
Ambient air temperature and installation altitude affect
the maximum output rating of the VFD66 controls (see
De-Rating the VFD66 Control for High Temperatures
and High Altitudes).
Wiring
!
WARNING: Risk of Electrical Shock.
The printed wiring board and its components are at
AC line voltage. Direct or indirect contact with line
voltage can result in personal injury or death.
!
WARNING: Risk of Electrical Shock.
The VFD66 controls remain electrically charged for a
period of time after power is removed. To avoid
possible electrical shock, wait at least 5 minutes
after AC supply power has been disconnected from
the VFD66 controls before servicing the control.
Failure to wait until the VFD66 control fully
discharges could cause electrical shock,
personal injury, or death.
!
CAUTION: Risk of Equipment Damage.
Connect each of these items to the VFD66 controls,
using a separate conduit for each set of wires:
•Line Voltage Supply Power
•Line Voltage Output Power to Fan Motor
•Low Voltage Signals from Input Devices
Running different voltage and frequency wires in the
same conduit can create electronic noise or
harmonics, which may damage the condenser fan
motors.
Read this entire section, including the information on
emissions compliance, before wiring the
VFD66 control. See Figure 5 for a view of the circuit
board components and the conduit entry bracket.
Accessing the Interior
Remove the terminal access cover (see Figure 2,
Figure 3, and Figure 4) to access terminal blocks,
jumper blocks, and internal potentiometers (see
Figure 5).

VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin 5
NEMA 1 Enclosure
Follow these steps to remove the terminal access
cover:
1. Remove the terminal cover screw.
2. Push downward on the ventilation holes.
3. Pull outward on the top of the terminal access
cover.
NEMA 4 Enclosure
Follow these steps to remove the terminal access
cover:
1. Remove the four terminal cover screws.
2. Grasp the rubber tab at the bottom of the terminal
access cover.
3. Pull the tab outward and upward to remove the
terminal access cover.
J7 J8
TB3
1 2 34
TB1
L3 L2 L1
TB2
P1
T1 T2 T3
J5 J6 J2 J3 J4 J9
Circuit
Board
(cropped
view)
Conduit
Entry
Bracket
Potentiometers
P2
Jumper
Blocks
for
Adjusting
VFD66
Control
Jumper Blocks for
Input Device Selection
Ground
Connection Terminals
Route wiring from input devices
through this conduit entry hole.
Input
Device
AC
Power
Input
Output
to
Fan
Motor
Figure 5: Jumper Block, Terminal Block, and
Potentiometer Locations
Table 3: Terminal Blocks
Terminal
Block Label
Terminal Block Function Electrical Rating Terminal Terminal Function
L1 Line 1 Input
L2 Line 2 Input
TB1 Input Line Voltage Power
L3 Line 3 Input
T1 Line 1 Output
T2 Line 2 Output
TB2 Output Line Voltage Power to Fan
Motor
See Technical
Specifications.
T3 Line 3 Output
1 5 VDC power supply
2 First signal input
3 Second signal input*
TB3 Low-voltage Input Signals,
0-5 VDC Power Supply
0-5 VDC or 0-10 VDC
4 Common
1 Switch contact
TB4 Alarm Output for User-Installed
Alarm Device
100 mA at 24 VAC/30 VDC
2 Switch contact
* See Adjusting the Control Settings.

6 VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin
Wiring an Input Device
Connect a low-voltage input signal device to Terminal
Block TB3 (see Table 3 and Figure 5). See Table 4,
Figure 6, Figure 7, and Figure 8 for information on
wiring specific Johnson Controls/PENN™ input
devices to the VFD66 controls.
Table 4: Wiring Johnson Controls/PENN
Input Devices
Input Device Input Device
Terminal
VFD66 Control
TB3 Terminal
11
2 2 (or 3)*
P35AG-9200R
Transducer
34
V 2 (or 3)*
A350PS-1C or
P352PN Series
Controls C4
Red 1
White 2 (or 3)*
P399 Series
Transducers
Black 4
* Use Terminal 3 for input from a second input device.
TB3
2
2
13
3 4
P35 Transducer
1
Figure 6: Wiring P35 Transducers to VFD66
Terminal Block 3
Red
White Black
Red (5 VDC Supply)
White
(Output Signal)
24
1
TB3
Black
(Common)
3
Figure 7: Wiring P399 Transducers to VFD66
Terminal Block 3
TB3
1
V
I
SN
VDC
C
24V
A350P Control
or P352PN Control
Second A350P Control
or P352PN Control
(if used)
2 4
C: Common (-)
V: 0-10 VDC Output
3
Figure 8: Wiring A350P Controls or P352PN
Controls to VFD66 Terminal Block 3
Wiring an External Alarm to the VFD66 Control
Some models of the VFD66 controls feature an alarm
output. The Metal Oxide Silicon Field Effect Transistor
(MOSFET) alarm output activates when a permanent
fault condition occurs. See Table 14, Figure 5, and
Figure 9.
Visual
or Audible
External Alarm
Device
Alarm output
is rated for 100 mA
at 30 VDC/24 VAC.
2
1
24VAC/30 VDC
VFD66 Control
Terminal Block T 4B
Figure 9: Wiring the Alarm Output
Wiring Power
Select wire size for field wiring based on a wire
insulation temperature resistance rating of 167°F
(75°C), with a maximum wire size of 12 AWG. Use
only stranded copper wire, rated for at least 600 volts.
Maximum terminal tightening torque for all VFD66
controls electrical terminals is 5 lb·in (0.565 N·m).

VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin 7
Ensure that the motor(s) and VFD66 control are
securely and adequately grounded. Use the two
ground connection terminals on the conduit entry
bracket. (See Figure 5.) Use a ground connection
terminal similar to AMP Part Number 34162 for
16-14 AWG wire size or AMP Part Number 322455 for
12-10 AWG wire size.
Wiring Input Power
!
CAUTION: Risk of Equipment Damage.
Wiring line-voltage input power to the wrong terminal
block will damage the VFD66 control. Wire input
power ONLY to Terminal Block 1 (TB1).
!
CAUTION: Risk of Equipment Damage.
Use of an incorrect power source may cause
equipment damage. Ensure that the power source
conforms to the requirements of the equipment.
The input line-voltage supply power to L1, L2, and L3
(Terminal Block 1) must be fused. Use fuses sized for
250% of the input current rating of the VFD66 control.
For example, if a VDF66 control is rated at 4 amperes
input current, use a 10-ampere fuse. Do not use fuses
with an extremely fast-opening characteristic (rectifier
fuses).
Wiring Output Power
IMPORTANT: The output phase rotation on TB2 at
T1(U), T2(V), T3(W) is ABC. If the motor rotation is
incorrect, interchange any two motor leads on TB2.
Do not make changes to the input power supply
wiring.
The length of output power wires between the
VFD66 control (TB2) and the motor must not exceed
50 ft (15 m).
Emissions Compliance
If the VFD66 control is used in commercial or
residential applications, FCC and DOC compliance
may require the addition of the items in Table 5 to
reduce electronic noise emissions. Installation of the
parts listed in Table 5 is required for EU Directive
Compliance (CE mark):
•72/23/EEC (Low Voltage Directive)
•89/336/EEC (EMC Directive)
Table 5: Emissions Compliance
Required Item Suggested Model
Axx, Bxx, Dxx,
and Fxx
Schaffner® EMV AG
FN 258-7/29*
EMI
Filter for
VFD
Types: Cxx and Exx Schaffner EMV AG
FN 258-16/29
Ferrite Core
(Two Required)
Fair-Rite® No.
04431672451
Shielded Power Wiring Any 3-conductor, braided,
shielded cable
* Contact Schaffner and Fair-Rite for local distributors.
TB3 TB1 TB2
1 2 34L1 L2 L3 T1 T2 T3
L1
L1
L2
L2
L3
L3
E
Motor
EMI Filter
E
Shielded
Wiring
Separate input and output cables. Do not run input cables
alongside output cables. Do not bundle input and output
cables together.
Input
Device(s)
Ferrite Cores
2, 3 or 4 Conductor
Shielded Cables
Alarm
Device
Figure 10: CE/FCC/DOC Compliance Wiring
Setup and Adjustments
This section describes how to set up the
VFD66 control. Remove the terminal access cover to
access the jumper blocks and internal potentiometers.
See Accessing the Interior.
Adjusting the Control Settings
!
WARNING: Risk of Electrical Shock.
The printed wiring board and its components are at
AC line voltage. Disconnect power from the control
before making any adjustments. Do not touch any
tool to any part of the wiring board while power is
applied. Failure to follow these precautions can
result in personal injury or death.
Control settings are established by positioning
six jumpers and adjusting two potentiometers.

8 VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin
Factory default settings have all the jumpers in the
installed position and the potentiometers set fully
clockwise. (See Table 6, Figure 5 and Figure 11.)
Table 6: Jumper Settings by Function
Jumper
Block
Function Jumper
Removed*Jumper
Installed
J2
J3
Mode of
Operation
See Selecting an Input Mode.
J4 Acceleration/
Deceleration
Time
5 Seconds 30 Seconds
J5 Internal/
External P1
J6 Internal/
External P2
Do not move the jumpers
from the factory-installed
position unless installing the
External Potentiometer
Replacement Cover.
J7 Input Signal
Type
0-10 VDC 0-5 VDC
J8 Number of
Input Signals
Used
Dual Single
J9 Maximum
Output
Frequency
50 Hz 60 Hz
* Do not discard jumpers. (See Figure 11.)
To place a jumper in the removed position, reposition
the jumper so that it is connected to only one pin on
the jumper block. Keep the jumper because it may be
needed in the future. To place a jumper in the installed
position, place the jumper on both pins. (See
Figure 11.)
Jumper blocks J2 and J3 establish input modes and
work in conjunction with potentiometers P1 and P2.
See Selecting an Input Mode.
Jumper
Pins
Removed
(positioned
on one pin)
Installed
(positioned
on both pins)
Jumper
Block
Figure 11: Jumper Placement on Pins
Jumper blocks J5 and J6 have jumpers installed on
the two middle pins of each jumper block. These
jumpers activate the internal potentiometers. Moving
the jumpers from the factory-installed position disables
the internal potentiometers.
Jumpers on J7 and J8 must be set for the correct input
voltage range and number of input devices. (See
Table 6.) Jumper block J7 sets the voltage range for
the input signal(s). If the jumper on jumper block J7 is
incorrectly set, the control may operate in an
unexpected manner. See Troubleshooting.
Jumper block J8 selects the number of input signals
used. When dual inputs are selected, Terminal 3 of
TB3 (TB3-3) is enabled. The VFD66 control varies the
speed of the fan motor in accordance with the higher
value of the two input signals received. If the jumper
on jumper block J8 is incorrectly set, the control may
operate in an unexpected manner. See
Troubleshooting.
Jumper block J9 selects maximum frequency output of
the control. Remove the jumper for 50 Hz motors,
typically used in Europe. Install the jumper for 60 Hz
motors, typically used in North America. Power to the
VFD66 control must be disconnected and reconnected
before frequency changes take effect.
De-Rating the VFD66 Control for High
Temperatures and High Altitudes
Ambient air temperature and altitude of the installation
affect the maximum output ampere rating of the
VFD66 control. High air temperature makes the heat
sink less effective in dissipating the generated heat.
High altitudes have thinner air than lower altitudes,
which is less effective in dissipating heat. The less
effective the heat sink is, the lower the maximum
output ampere rating of the VFD66 control.
Temperature De-Rating
For temperatures up to 122°F (50°C), the maximum
output ampere rating is unaffected by temperature. At
temperatures between 122°F (50°C) and 140°F
(60°C), the maximum output ampere rating is
decreased. The VFD66 controls are not designed to
operate in temperatures above 140°F (60°C).
See Figure 12 for temperature de-rating for
208/230 VAC models. See Figure 13 for temperature
de-rating for 400/460 VAC models.

VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin 9
Amperes
Temperature
10.0
0
5.0
7.5
2.5
122 F
50 C
o
o
140 F
60 C
o
o
131 F
55 C
o
o
126 F
52 C
o
o
136 F
58 C
o
o
4.0
10.6
VFD66Axx Type
VFD66Cxx Type
VFD66Exx Type
Figure 12: 208/230 VAC Temperature De-Rating
Amperes
Temperat ure
6.0
0
3.0
4.5
1.5
122 F
50 C
o
o
140 F
60 C
o
o
5.5
1.8
3.6
2.2
131 F
55 C
o
o
126 F
52 C
o
o
136 F
58 C
o
o
VFD66Fxx Type
VFD66Dxx Type
VFD66Bxx Type
Figure 13: 400/460 VAC Temperature De-Rating
Altitude De-Rating
See Table 7 for altitude multipliers. Use the following
formula to determine the adjusted rating:
Temperature
De-Rated
Maximum
Output
Amperes
XAltitude
Multiplier =
De-Rated
Maximum
Output
Amperes
Table 7: Altitude Multipliers for De-Rating
Altitude Range Altitude Multiplier
0-3300 ft (0-1000 m) 1.0
3300-4300 ft (1000-1305 m) 0.97
4300-5300 ft (1305-1610 m) 0.94
5300-6300 ft (1610-1915 m) 0.91
6300-7300 ft (1915-2220 m) 0.88
7300-8300 ft (2220-2525 m) 0.86
8300-9300 ft (2525-2830 m) 0.83
9300-10300 ft (2830-3135 m) 0.80
10300-11300 ft (3135-3440 m) 0.78
De-Rating Examples
For these examples, the control used is a VFD66Exx
type. See Figure 12, Figure 13, and Table 7.
•If a VFD66Exx type (208/230 VAC) is used and
the temperature is below 122°F (50°C), the VFD66
control may be used for loads up to 10.6 amperes
at any altitude below 3300 ft (1000 m).
•If the temperature around the VFD66 control
reaches 140°F (60°C), the rating is different.
According to Figure 12, the VFD66 control is rated
for only 7.5 amperes at 140°F (60°C).
•If the VFD66 control is used in Denver, Colorado
(altitude 5200 ft), the output rating is reduced.
(See Table 7.) When the temperature is less than
122°F (50°C), the VFD66 control is rated for
9.96 amperes, as shown by the equation:
De-Rated Maximum Output Amperes = 10.6 Amperes
x 0.94 = 9.96 Amperes
•If the VFD66 control is used in Denver, Colorado
(altitude 5200 ft), and the ambient temperature
reaches 140°F (60°C), then the VFD66 control is
de-rated to a 7.5-ampere maximum current draw
due to the high ambient temperature and is further
de-rated to 7.05 amperes of current draw because
of high altitude.
De-rated Maximum Output Amperes = 7.5 Amperes x
0.94 = 7.05 Amperes

10 VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin
Commissioning
Table 8: Mode Selections According to Input Device
Input Device Input Type Input Mode J2 Jumper
Position
J3 Jumper
Position
J7 Jumper
Position2
Any1None1Manual Installed Installed NA
A350P Temperature Standard Installed Removed Removed
P352PN Pressure Standard Installed Removed Removed
P35AG-9200 Pressure Standard Installed Removed Installed
Any 0-5 VDC Devices Any3Standard Installed Removed Installed
Any 0-10 VDC Devices Any3Standard Installed Removed Removed
P399 or Other Electronic
Pressure Transducer
Pressure Electronic Pressure
Transducer
Removed Removed or
Installed4Removed or Installed4
1. Setting the mode to manual ignores the input devices.
2. Position of jumper on J7 depends on the input device used.
3. Input type varies with device.
4. Transducer may provide 0-5 VDC or 0-10 VDC signal. A 0-10 VDC transducer must be separately powered. Note that
a non-ratiometric transducer will have more error.
Selecting an Input Mode
See Table 8 for the available input mode options for
the VFD66 control. The factory–set mode is Manual
Input mode.
Manual Input Mode
Manual Input mode allows the user to set a constant
motor speed. This can be used where manual control
is desired or while repairing input signal devices or
obtaining replacements. In Manual Input mode, the input
device signals are disregarded. Motor speed is controlled
by adjusting the P1 potentiometer. Potentiometer P2 is
disregarded and adjusting P2 has no effect.
Table 9: Manual Input Mode
J2 Jumper
Position
J3 Jumper
Position
P1:
Motor Speed
P2:
Not
Used
Installed Installed Adjusts constant
speed of motor
(0-100%)
—
Standard Input Mode
Standard Input mode is the most commonly used
mode. The majority of input devices compatible with
the VFD66 controls are used with this mode. The input
device determines the setpoint and proportional band.
Table 10: Standard Input Mode
J2
Jumper
Position
J3
Jumper
Position
P1:
Minimum
Motor
Speed
P2: Motor
Action at
Minimum
Speed
CCW:
Motor idles.
Installed Removed Can be set at
0-50% of
maximum
motor speed. CW: Motor
shuts off.
P1 adjusts the minimum speed of the motor. The
minimum speed is adjustable from 0 to 50% of total
motor speed.
P2 determines whether the motor idles at minimum
speed or shuts off at minimum speed. P2 must be set
at full Counterclockwise (CCW) or full Clockwise (CW)
position; intermediate settings have no effect.
Figure 14 illustrates three possible motor speed
curves. When P2 is rotated fully CCW, the motor idles
at the minimum speed set by P1 at input values below
the end of the proportional band (Curve A in
Figure 14). When P2 is rotated fully CW, the motor
shuts off at the minimum speed set by P1 when the
input is below the bottom end of the proportional band
(Curve B in Figure 14).
In Curve C, the minimum motor speed (P1) is set at
0% of maximum motor speed and the position of
P2 has no effect.