SAF Opal Pro MS6 Series, MS6-30, MS6-80, MS6-125, MS6-250, MS6-50, MS6-420, MS6-500, MS6-600, MS6-800 Installation & Operating Procedures
Specifications and Main Features
Frequently Asked Questions
User Manual
Installation & Operating Procedures
Opal Pro MS6
Series
SOLID STATE REDUCED VOLTAGE STARTER
FOR 3 PHASE INDUCTION MOTORS
Opal Pro MS6 SERIES
SOLID STATE REDUCED VOLTAGE
STARTER
FOR 3 PHASE INDUCTION MOTORS
Revision 1.08 - 01/2011
MS6 REDUCED VOLTAGE STARTER
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MS6 REDUCED VOLTAGE STARTER
FOR YOUR SAFETY
Only qualified personnel should install this equipment, after first reading
and understanding all the information in this manual. All instructions should
be strictly adhered to. The user should consult SAF Drives Inc. or a SAF
OPAL Starters supplier for clarification of the contents of this manual should
any doubt or questions arise.
The installation of this equipment must be conducted in accordance with all
national, regional and local electrical codes.
All drawings and technical representations included in this manual are for
typical installations and should not in any way be considered for specific
applications or modifications. Consult SAF OPAL Starters for supplemental
instructions.
SAF Drives Inc. accepts no liability for any consequences resulting from
inappropriate, negligent or incorrect installation, application or adjustment of
this equipment.
The contents of this manual are believed to be correct at the time of
printing. In following with our commitment to the ongoing development and
improvement of our products SAF OPAL Starters reserves the right to
change the specification of this product and/or the content of this instruction
manual without notice.
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MS6 REDUCED VOLTAGE STARTER
TABLE OF CONTENTS
1 MS6 GENERAL DESCRIPTION................................................................................................. 7
1.1.1 STANDARD FEATURES ...................................................................................................................................7
1.2.3 MOTOR AND LOAD TYPES............................................................................................................................9
1.2.4 STARTING AC MOTORS IN PARALLEL .....................................................................................................9
2.1 POWER RATING.....................................................................................................................................................10
2.2 MAXIMUM RATINGS............................................................................................................ ................................10
2.3 SERVICE CONDITIONS ........................................................................................................................................10
2.5.1 STANDARD UNIT.............................................................................................................................................12
2.5.2 REVERSING UNIT (OR STANDARD UNIT WITH DC INJECTION).....................................................12
5.5.1 BEFORE POWER-UP.......................................................................................................................................18
5.5.2 WITH POWER ON ...........................................................................................................................................18
7.6 SOLID STATE FULL SPEED REVERSING........................................................................................................21
7.7 DC INJECTION BRAKING....................................................................................................................................22
10.1 TWO WIRE CONTROL.......................................................................................................................................29
10.3 THREE WIRE REVERSING...............................................................................................................................31
10.4 THREE WIRE WITH BY-PASS..........................................................................................................................32
10.5 THREE WIRE CONTROL WITH SHORTED SCR DETECTION................................................................33
10.6 DCI FOR 80 AMP UNITS AND BELOW...........................................................................................................34
10.7 DCI FOR 125 AMP UNITS AND ABOVE..........................................................................................................35
The Opal Pro series is a processor controlled line of solid state reduced voltage starters for use
with 3 phase induction motors. This series also includes various communication options,
which can be easily added to connect to standard industrial networks.
A solid state starter provides a step-less, smooth current ramp to the motor. This characteristic
eliminates current surges and mechanical torque transients. Since these units are solid state, we
now eliminate the maintenance of moving contacts, which are involved in almost any other
method of starting an AC induction motor.
1.1.1 STANDARD FEATURES
• 200 – 600 VAC 3 phase universal voltage, 50/60Hz with no adjustment
• Single control card through out Opal Pro range
• Current regulated closed loop
• Dual operation modes to match any application:
Constant Current mode for light loads or limited power supplies
Current Ramp mode for high inertia or heavy loads
• Soft stop
• Jog Speed:
14% of full speed forward
20% of full speed reverse
• Two or three wire control
• 120 VAC control inputs for:
Start
Stop
Jog
Reverse
Reset
Enable
• Keypad and LCD display for starter setup and diagnostics
• Single phase protection
• Phase rotation insensitive
• Instantaneous over-current trip
• Class 10, 15, 20, or 30 electronic motor overload
• Shorted SCR Fault output
• Shear pin Fault
• Dry contact relay outputs for:
Fault
By-pass
Shorted SCR
Running
Reverse
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MS6 REDUCED VOLTAGE STARTER
1.1.2 OPTIONAL FEATURES
• By-Pass Contactor
Once the motor has reached operational speed, the by-pass contactor is closed. This
shorts the SCR’s which eliminates the voltage drop across the SCR’s, in turn being more
efficient and ridding excess heat.
• Solid State Full Speed Reversing
Through the addition of 4 SCR’s and a reversing card, smooth motor reversing is
achieved without having to stop the motor.
• DC Injection Braking
Through the addition of SCR’s and a DC injection card, adjustable electric braking of the
AC motor is performed.
• Various communication options, which will allow connection to standard industrial
networks
• NEMA 4 or NEMA 12 enclosures
1.2 APPLICATION NOTES
1.2.1 OPERATION MODES
With any induction motor the design is such that starting currents and torques are very high.
Across the line starting for a basic NEMA B design motor creates an in-rush current of 600%
or more of the nameplate rating. Often these levels are so high that they cause problems with
mechanical or auxiliary electrical. An example of this is the high starting torques which cause
belt slip and high currents, creating large voltage dips. The basis of choosing the correct
starting mode is determining the problem to be solved.
1.2.2 CHOOSING STARTING MODE
Constant Current Mode
Soft Starting for light loads or reducing starting current are accomplished by using the Constant
Current Mode.
On some applications the starting time is still too fast in the current ramp mode because the
load is too light. In this application it is best to select the constant current mode which will
allow the acceleration torque to be better controlled, actually kept constant.
If the available current is limited and causes significant voltage drops, the constant current
mode will allow flexibility in setting the current draw. Remember that the current level must be
great enough to provide acceleration torque and this level is determined by the load.
For all other applications, or if in doubt, select the Current Ramp Mode.
Current Ramp Mode
Torque Reduction on heavy loads is accomplished by using the Current Ramp Mode.
The idea is to reduce starting current to just above the level, which will produce enough torque
to get the motor to move. This is commonly referred to as "break-away torque". As the current
ramps up from this point, the torque also increases as time passes. If at the initiation of start,
the motor torque is less than the load, the motor will remain stalled until the torque ramps to a
sufficient level for acceleration.
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1.2.3 MOTOR AND LOAD TYPES
Squirrel Cage Motors
Squirrel cage motors, with a single winding and of any NEMA design may be connected to the
Opal Pro starter.
Wound Rotor Motors
Wound Rotor Induction Motors (WRIM) and solid state starters make an excellent combination
for frequent starting, jogging, plug-stopping and reversing applications. These WRIM motors
use multiple steps of resistors to provide various speed torque characteristics. This allows a
high starting torque characteristic while providing low starting current when compared to
NEMA B designs.
One disadvantage has been the high maintenance costs of the resistor and shorting contactor
bank. The use of an Opal Pro allows an improvement to this arrangement by allowing the
current to be limited without use of the multiple steps. Usually the load characteristic is such
that this starting may be accomplished with only one or two starting steps. By eliminating
several contactors a major savings is realized that often pays for the installation cost.
The common method is to add only one step of resistance at 20% (Rotor volts divided by Rotor
Amps times 20%). This resistance value will provide relatively high starting torque and the
Opal Pro will be used to limit the current. As little as 200% of motor full load current can
provide 100% starting torque unlike squirrel cage NEMA B motors which would require 500%
current. The resistor bank may be shorted with a contactor at full speed to reduce the slip and
eliminate the watt losses in the resistors.
Other Types of AC Motors
Opal Pro starters may also be used to start 2-speed motors with multiple windings or
connections. Proper contactor selection and sequencing is required for the specific motor.
Resistive and Inductive Loads
The Opal Pro MS6 is well suited for use as a phase controller or current regulator on resistive
or inductive loads such as heaters. When applied with a Temperature PI controller, the Opal
Pro MS6 will maintain smooth control to avoid the overheating associated with on/off type
controllers. Improved temperature accuracy and longer heater element life can be expected
over standard control methods.
1.2.4 STARTING AC MOTORS IN PARALLEL
Opal Pro MS6 starters can be used to start motors in parallel but they must have individual
overload devices added.
When the paralleled motors are also connected to the same load, mechanically or through the
material, then load sharing must be considered.
When the motors are mechanically tied, the load sharing is determined by how closely the
motor characteristics are to each other. It is important to keep the motors exactly the same.
Even changing the manufacturers of the motors can cause some variations in load sharing. The
Opal Pro size is determined by the total of the motor current ratings.
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2 SPECIFICATIONS
2.1 POWER RATING
Power 3 phase, 200-600 VAC, 50/60Hz
Control 115VAC 50Hz or 120VAC 60Hz
Rating See Section 2.2
All models have 1600V PIV SCR’s
Digital Inputs 120VAC, 2mA
Digital Outputs Relay contacts rated at 0.2A, 120VAC
By-Pass Output Relay contact rated at 5A, 120VAC
Analog Input 0 – 10Vdc
Analog Output 0 – 5Vdc, 5mA max
Protection Short circuit by HRC fuses or circuit breaker (supplied upon request)