Danfoss Cascade Operating Instructions Manual
Contents
■
Cascade Controller Option
Safety
Safety regulations ................................................................................................... 4
Warning against unintended start ........................................................................... 4
Operation m odes
Cascade Control Operation ................................................................................... 6
Standa
Master/Slave Cascade Control Mode .................................................................... 8
Instal
Installing the cascade controller option card .......................................................... 9
Standard cascad e control wiring diagram .............................................................. 17
Option
Master drive in master/slave control wiring diagram .............................................. 19
Slave drive in master/slave control wiring diagram ................................................. 20
Changed Drive functions
Introduction ............................................................................................................ 21
Changed
Serial communications(parameter 500) .................................................................. 22
and precautions
............................................................................................ 6
rd Cascade Control Mode .......................................................................... 7
lation and Wiring Instructions
al Hand/Off/Auto Switch .............................................................................. 18
systemstop functions .............................................................................. 22
................................................................................ 3
..................................................... 9
............................................................................ 21
User Int
How to use the LCP for programming ................................................................... 23
Control keys for parameter setup .......................................................................... 23
Indicat
Drive Control .......................................................................................................... 23
Display modes ....................................................................................................... 24
Changin
Parameter setting procedure .................................................................................. 26
Example of how to change parameter data ........................................................... 26
Manual in
VLT D rive and Cascade Controller Setup
Introduc
Quick Menu Summary ........................................................................................... 29
Language ............................................................................................................... 29
Motor nam
Relay outputs ......................................................................................................... 32
Alternate programming ........................................................................................... 36
Standard Cascade Controller Setup
Introduction ............................................................................................................ 38
Initial S
Alternate programming ........................................................................................... 45
erface
or lamps ...................................................................................................... 23
g data ....................................................................................................... 25
itialization ................................................................................................ 26
tion ............................................................................................................ 28
eplate data ............................................................................................ 30
etup ............................................................................................................ 39
................................................................................................... 23
........................................... 28
..................................................... 38
Master/S
Introduction ............................................................................................................ 46
Initial Setup ............................................................................................................ 46
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lave Cascade Control Setup
................................................... 46
1
Cascade Controller Option
Step 1: Master drive programming ........................................................................ 46
Step 2: Slave drive programming .......................................................................... 49
ate programming: .......................................................................................... 50
Altern
System Optimisation
System
Best efficiency frequency ....................................................................................... 52
Optimization of the process regulator .................................................................... 53
start up and final adjustments ................................................................... 52
Feedback Transmitter Wiring
Connecting feedback transmitters ......................................................................... 54
Single 0
Two 0 - 10 V feedback transmitter connections: ................................................... 54
Two 4 - 20 mA feedback transmitters connection: ................................................ 55
Two feed
Programming example ........................................................................................... 55
Paramet
Parameter group 700 d efinitions ............................................................................ 57
Service
Display information ................................................................................................. 58
Relay status ........................................................................................................... 59
- 10 V feedback transmitter connection: .................................................. 54
back signals and two setpoints: .............................................................. 55
er group 700, all parameters
parameters
.................................................................................... 52
................................................................... 54
................................................... 57
........................................................................................ 58
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MG.60.I3.02 - VLT is a registered Danfoss trademark
Safety and precautions
■
Cascade Controller Option
Cascade Controller Option
175ZA677.11
for
VLT 6000 HVAC
and
Safety and precautions
VLT 8000 AQUA
Operating Instructions
When reading through this Operating Instructions,
you will come across various symbols that
require special attention.
The symbols used are the following:
Indicates a general warning.
NB!:
Indicates something to be noted by the reader.
Indicates a high-voltage warning.
MG.60.I3.02 - VLT is a registered Danfoss trademark
3
Cascade Controller Option
The voltage of the frequency converter
is dangerous whenever the equipment is
connec
of the motor or the frequency converter may cause
damage to the equipment, serious personal injury
th. Consequently, the instructions in this
or dea
manual, as well as national and local rules and
safety regulations, must be complied with.
NB!:
UsingtheVLTDialogSoftwareorthe
FC protocol for serial communication can
cause unintended behaviour of motors
and plant and must be avoided.
Safety regulations
■
1. The VLT frequency converter must be
on-nected from mains if repair work is to be
disc
carried out.Check that the mains supply has been
disconnected and that the necessary time has
sed before removing motor and mains plugs.
pas
2. The [OFF/STOP] key on the control panel of the
VLT frequency converter does n
equipment from mains and is thus n
the
to be used as a safety switch.
ted to mains. Incorrect instal-lation
ot disconnect
ot
necessary time has passed before removing
motor and mains plugs.
7. Reliab
8. Please note that the VLT frequency converter
Warning against unintended start
■
1. The motor can be brought to a stop by
2. While parameters are being changed, the
le galvanic isolation (PELV) is not complied
with if the RFI switch is placed in OFF position.
This means that all control in- and outputs
ly be considered low-voltage terminals
can on
with basic galvanic isolation.
has mo
the DC-bus terminals are used. Check that
all voltage inputs have been disconnected and
that t
repair w o rk is commenced.
means of digital commands, bus commands,
references or a local stop, while the frequency
converter is connected to mains.
If personal safety considerations make it necessary
to ensure that no unintended start occurs, t
stop functions are not sufficient.
motor may start. Consequently,
[OFF/ STOP] must always be activated, after
which data can be modified.
re voltage inputs than L1, L2, L3 when
he necessary time has passed before
the stop key
hese
NB!:
The IMMEDIATE STOP function will release all
slave relays a
switch. The SEQUENCED STOP will stage off
the slave relays a
3. Correct protective earthing of the equipment
st be established, the user must be protected
mu
against supply voltage, and the motor must be
protected against overload in accordance with
plicable national and local regulations.
ap
4. The earth leakage currents are higher than 3.5 mA.
5. Protection against motor overload is included
the factory setting. Parameter 117, Motor
in
thermal protection, default value is ETR trip
1. For the North American market: The ETR
unctions ensure overload protection of the motor,
f
Class 20, in accordance with NEC.
NB!:
Motor Thermal Protection is initialised at 1.0 x
rated motor current and rated motor frequency
(see parameter 117, Motor thermal protection).
nd can not be used as a safety
nd can not be used as a safety switch
6. Do n
4
ot remove the plugs for the motor and
mains supply while the VLT frequency converter
is connected to mains. Check that the mains
supply has been disconnected and that the
MG.60.I3.02 - VLT is a registered Danfoss trademark
Cascade Controller Option
Warning:
Touching the electrical parts may be fatal - even after the equipment has
been disconnected from mains.
200-240 and 380-480 V: wait at least 15 minutes
550-600 V: VL T 6002/8002 - 6027/8027: wait at least 15 minutes
550-600 V: VL T 6032/8032 - 6300/8300: wait at least 30 minutes
175ZA678.11
Safety and precautions
MG.60.I3.02 - VLT is a registered Danfoss trademark
5
Operation modes
■
Cascade Control Operation
■
With the cascade controller option card, the frequency
converter can automatically control up to five
motors. Staging motors on or off is done cyclically,
in accordance with operating hours. This function
assures equal use over time and eliminates concern
about starting a seldom used motor. The cascade
controller includes four Form C relays having contacts
rated 250 V, 2 A (non-inductive) that are used to
control the motor con tactors. The controller option
card installs in the frequency converter control card
cassette and can be ordered factory installed. The
cascade controller is effective in applications where
multiple motors are used to control a common flow,
level or pressure involving pumps, fans, and blowers.
eedback Signals
F
An important advantage to the cascade controller
option is that it is based upon the VLTs advanced
PID controller. This means that programming is
done in selected units of measurement appropriate
to the application and that the feedback and
setpoints can be displayed. Unlike drives that base
staging upon frequency, feedback allows precise
control in response to actual system demand. The
VLTs PID controller accommodates two feedback
signals and two setpoints which allows regulating
a system with different setpoint zones.
Cascade Controller Option
In pumping applications, when a pressure feedback
signal is not practical, the feedback signal may be
taken near the pump by measuring flow. When the
flow rate is low, the pressure needed is low. At
increased flow, the pumps need to provide greater
pressure to compensate for the increased pressure
drop in the piping. The setpoint should be adjusted
to match the flow in these cases. While difficult
to accomplish with standard PID controllers, the
cascade controller provides an easy solution. By
programming one setpoint for minimum flow and
the other for maximum flow, the VLT calculates
intermediate setpoints based on the flow required.
Cascade control operation depends on the general
system design. Two operational modes are available:
1. Standard Cascade Control, with one speed
controlled pump/fan and up to four fixed
speed pumps/fans. Programming for this
mode is described in Chapter 6, Standard
Cascade Control Mode Setup.
2. Master / Slave Cascade Control has all
pumps/fans speed controlled through the Master
drive. Programming is described in Chapter 7,
Master/Slave Cascade Control Mode Setup.
Standard Cascade Control Mode
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MG.60.I3.02 - VLT is a registered Danfoss trademark
Standard Cascade Control Mode
■
In standard cascade control, a frequency converter
e Cascade Controller option card installed
with th
controls a variable speed motor and is used to
stage additional constant speed motors on and
y varying the speed of the initial motor,
off. B
variable speed control is provided for the system.
This maintains constant pressure while eliminating
ure surges, resulting in reduced system
press
stress and quieter operation.
The motors can be of equal or differing sizes. The
controller offers a selection of eight pre-defined pump
combinations. Selections allow mixing pumps of
100%, 200% and 300% capacity. This provides a
dynamic capacity range of 9 to 1. The VLT drives
internal PID controller directs the cascade option
card based upon the feedback signal. The cascade
controller will continue operation of the constant speed
motors to meet demand should the drive trip.
Cascade Controller Option
When the master drive is the only one running, the
drives sleep mode can discontinue system operation
when not needed while staying ready to start on
demand. Variable speed control with fixed speed
motors optimizes energy consumption and avoids
damaging a pump running at near no flow condition
L
evel Control
With level control, multiple pumps can be used to
keep a constant level in applications such as a buffer
tank. Typically, a water level sensor provides a
feedback signal for the VLT’s built-in PID controller.
Precise level control is maintained in response to
the system setpoint. With a cascade controller,
additional fixed speed pumps will be staged on or
off, as required, to maintain level control.
stage Timer
D
eA de-stage timer takes effect in standard control
when the drive runs continuously at minimum speed
h one or more constant speed motors running.
wit
Since a variable speed pump at minimum speed
adds no or very limited flow to the system, it is
visable to stop a constant speed motor and
ad
allow the drive to provide the required flow. The
de-stage timer is programmable to avoid frequent
taging of the constant speed motors.
s
Operation modes
Level Control in Standard Cascade Control Mode
MG.60.I3.02 - VLT is a registered Danfoss trademark
7
Master/Slave Cascade Control Mode
■
Master/slave systems control multiple pumps in
el at the same output frequency. Pumps are
parall
staged on and off as required to meet the systems
demand. The master/slave control mode of operation
des maximum system efficiency.
provi
In master/salve control, each motor has its own
adjustable frequency drive which responds to control
from a master drive which contains the cascade
option card. The master drive sends a pulse speed
reference signal to the drives under control to ensure
that all operate at the same speed. The motors
must be of equal size. In some applications, it may
be advisable for a second drive with a cascade
card to act as an auxiliary controller.
Sequential staging of drives on or off is provided by
master drive in response to system feedback,
the
maintaining precise setpoint control. Pressure surge
and water hammer are eliminated. Because all
he operating pumps run at the same speed,
of t
the possibility of running a pump continuously into
a closed check valve is all but eliminated. This
duces pump maintenance by minimizing the
re
wear on pump seals and bearings.
Cascade Controller Option
Danfoss has available the Multiple Unit Staging
Efficiency Calculator (MUSEC), a free software program
available on the Danfoss website. By entering pump
and system data, MUSEC provides the programmer
with master drive on and off staging frequencies
at optimal efficiency for each pump: for example,
three motors providing flow at reduced speed rather
than two at full speed. This often results in 10% to
15% additional savings over similar control systems.
For a free download, go to www.danfoss.com
and enter MUSEC in the search box.
Best efficiency is attained when a pressure transmitter
is placed at the farthest significant load in the system.
If this is not practical and the pressure transmitter
is placed close to the discharge of the pumps, or
when pump data and system characteristics are
not accessible, alternative ways of programming
the cascade controller are provided.
Master/Slave Cascade Control Mode
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MG.60.I3.02 - VLT is a registered Danfoss trademark
Installation and Wiring Instructions
■
Installing the cascade controller option card
■
This chapter provides instructions for installing the
cascade controller option card into a VLT adjustable
frequency drive. In Standard cascade control mode,
the option card installs into the VLT controlling up to
four additional motors. In Master/Slave mode, the
option card installs in the Master drive controlling
up to four additional slave drives.
Cascade Controller Option
DANGER
VLT adjustable frequency drive
contains dangerous voltages when
connected to line voltage. After
disconnecting from line, wait at least 14 minutes
before touching any electrical components.
Relay o utput connections vary according to the mode
of operation and configuration of the system. Typical
wiring diagrams are also provided in this chapter.
Adhere to all safety guidelines provided in
the VLT Operating Instructions. See the
VLT Operating Instructions for details and for
instructions on drive operation.
orque tightening requirements
T
Tighten all fittings described in this chapter to 7.1
in-lbs (0.8 Nm), unless specified otherwise.
O
ptional transmitter connections
VLT drive terminals12 and 13 provide a 24 VDC,
200 mA power supply. This supply can be used
to power remote transmitters without need for an
external power supply. See wiring instructions in
Chapter 10, Feedback Transmitter Wiring.
WARNING
Only a competent electrician should
carry out electrical installation.
Improper installation of motor or VLT
can cause equipment failure, serious injury
or death. Follow this manual and National
Electrical Code and local safety codes.
CAUTION
Electronic components of VLT
adjustable frequency drive are
sensitive to electrostatic discharge
(ESD). ESD can reduce performance or destroy
sensitive electronic components. Follow
proper ESD procedures during installation
or servicing to prevent damage.
Installation and
Wiring Instructions
MG.60.I3.02 - VLT is a registered Danfoss trademark
9
Cascade Controller Option
1. Access to Control Card Cassette
■
•
Remove Local Control Panel (LCP) keypad by
g out from top by hand. LCP connector
pullin
on panel back will disconnect.
•
Remove terminal protective cover by gently
prying with screw driver at top notch and lift
cover o
•
Open access cover to internal VLT components.
(Drive configurations vary.)
ut of guide pin fittings.
2. Disconnect VLT Drive Control Wiring
■
Touching electrical parts may be fatal
– even after equipment has been
disconnected from AC line. To be sure
that capacitors have fully discharged, wait 14
minutes after power has been removed before
touching any internal component.
•
Remove control wiring by unplugging
connector terminals.
•
Remove wiring clamp by removing two
screws. Save for reassembly.
•
Loosen two captive screws securing control
board cassette to VLT chassis.
10
MG.60.I3.02 - VLT is a registered Danfoss trademark
Cascade Controller Option
3. Remove VLT Cassette and Ribbon Cables
■
•
Lift control board cassette from bottom.
•
4. Remove LCP Keypad Cradle
■
•
•
nect two ribbon cables from VLT
Discon
control board.
Push tabs at side of LCP cradle to release clips.
Pull out to disengage and lift cradle free.
•
Unhinge cassette at top to remove.
Installation and
Wiring Instructions
MG.60.I3.02 - VLT is a registered Danfoss trademark
11
5. Cascade OptionCard Ribbon Cable Routing
■
Electronic components of VLT and
cascade controller option card are
sensitive to electrostatic discharge
(ESD). Follow proper ESD procedures to
prevent component damage. ESD procedures
to prevent component damage.
Cascade Controller Option
•
•
•
•
6. Secure Option Card
■
•
ribbon cables from cascade controller
Route
option card through slot at side of VLT
control board cassette. Option card mounts
component side down.
with
Feed plastic option card insulation pad through
terminal opening in control board cassette.
rt edge of option card into slot (A)
Inse
in side of cassette.
Align opposite side of card with mounting
s (B) provided.
hole
Secure option card to control board cassette
with 3 self-tapping screws and washers provided.
Use a Torx T-10 screw driver.
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MG.60.I3.02 - VLT is a registered Danfoss trademark
7. Connect Option Card Ribbon Cable to
■
VLT Control Board
•
Pull up
cable socket.
•
DO NOT remove blue insulation on end of
option
into corresponding socket (B) on VLT control
board and push collar closed. Be sure not
to cri
•
Repeat procedure for all ribbon cables.
collar (A) of control board ribbon
card ribbon cable. Insert ribbon cable
mp ribbon cables.
Cascade Controller Option
Installation and
Wiring Instructions
MG.60.I3.02 - VLT is a registered Danfoss trademark
13
Cascade Controller Option
8. Chassis Ground Connection
■
•
Location of holes to mount grounding strips in VLT
chassis can vary with drive configuration.
•
When applicable, remove mounting screws
located in chassis using Torx T-20 screw driver
and save for reassembly. Otherwise, grounding
strips attach with screws provided.
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MG.60.I3.02 - VLT is a registered Danfoss trademark
9. Install Chassis Ground Connections
■
•
Align ground strips over corresponding screw
(Strip with fewest contact points mounts
holes.
on right side of chassis.)
•
Replace screws removed and add additional
screws
Torx T-20 screw driver.
10. Replace VLT Control Board Cassette
■
•
Attach LCP keypad craddle to VLT control
board cassette removed in step 4. Ensure not
to crimp option card ribbon cables.
•
Connect two ribbon cables to control board in
corresonding connectors as removed in step 3.
•
Hinge VLT cassette at top of VLT chassis and
reposition into place. Use Torx T-20 screwdriver
to fasten two captive screws. Ensure not to
crimp control board ribbon cables.
provided, as necessary. Use a
Cascade Controller Option
11. Relay Output Connection
■
•
Connect relay output cables to terminal blocks
provided as required by application. (See
wiring diagrams in this chapter.)
•
Insert relay terminal blocks firmly into corresponding
terminal sockets on control board.
•
Secure relay wiring with bottom right wiring
clamp and fasten.
Relay 6-9: A-B make, A-C break
Max. 240 VAC, 2 A
Max. cross-section: 1.5 mm
Torque: 0.22 - 0.25 Nm
2
(28-16 AWG)
Installation and
Wiring Instructions
MG.60.I3.02 - VLT is a registered Danfoss trademark
15
12. Remove Wiring Clamp Mounting Fixture
■
•
Option card insulation pad is designed to use top
most ca
•
Use screw driver to remove top most wiring clamp.
13. Reconnect VLT Control Terminals and
■
Secure Option Card InsulationPad
•
Reconnect VLT control terminals removed in step
2bypressingfirmlyintocorresponding
terminal socket.
•
Crease option card insulation pad flap and insert
into slot in side of control card cassette.
•
Attach insulation pad to top most clamp position
with one screw from removed wiring clamp.
•
Route VLT control terminal wiring through
bottom left wiring clamp and fasten.
ble wiring clamp screw hole for attaching.
Cascade Controller Option
14. Final Reassembly
■
•
Secure access cover to internal VLT components.
•
Replace LCP keypad by positioning guide slots
at bottom of cradle and snaping into place.
•
Attach terminal protective cover by positioning
guide pins at bottom of cover into control card
cassette and snaping into place.
Transmitter wiring
■
Please refer to chapter 10, Feedback
Transmitter Wiring.
16
MG.60.I3.02 - VLT is a registered Danfoss trademark
Standard cascade control wiring diagram
■
The wiring diagram shows an example for a
rd cascade control system with 4 fixed
standa
speed motors, a 4-20 mA pressure transmitter,
and external safety interlock.
Cascade Controller Option
Power terminal connections Control board terminal
connections
Option card terminal connections
Installation and
Wiring Instructions
MG.60.I3.02 - VLT is a registered Danfoss trademark
17
Optional Hand/Off/Auto Switch
■
ptional Hand/Off/Auto Switch
O
dard cascade control mode, an optional
In stan
Hand/Off/Auto switch on the constant speed motor
starter is common. During normal operation, the
switch
automatic start and stop commands to the motor.
The HAND position allows manual operation of the
motor
switch to OFF. For a motor in the OFF position, the
is set to AUTO and the drive will signal
. The motor can be disabled by setting the
Cascade Controller Option
cascade controller will try to start it by triggering
its relay. Since no contribution will occur, the next
pump will be switched on. The relay timer will,
however, assume operation for a disabled motor.
See Chapter 12, Service Parameters.
The diagram below provides wiring instructions
for an optional Hand/Off/Auto switch.
18
MG.60.I3.02 - VLT is a registered Danfoss trademark
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