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MSC 700™ DC Motor Adjustable Speed Controls
Introducing the industry’s most innovative
DC motor speed controls. MSC 700
controls from A. O. Smith.
The fact is, no other speed control even comes close. Because
no other control offers as much convenience, as much quality or as
much affordability.
Convenience and control all in one compact unit.
Whatever your application, count on our MSC 700 units for all the
control you need.
The way they work is simple. They statically convert single phase
AC power to regulated DC. So you get adjustable, reliable speed
control for either permanent magnet or wound field DC motors.
Our controls have adjustable trimpots for easy access to a wide
range of horsepower settings. You won’t have to stock an assort-
ment of shunt resistors to accommodate various horsepower needs.
You can operate our enclosed, dual-voltage models on either 115V
or 230V AC.
There’s more. You can choose from chassis and enclosed models,
with single or dual voltage operation. And for added versatility,
there’s more than a dozen optional accessories.
A. O. Smith means quality you can count on.
But perhaps the best feature in our control line is the name that’s
behind it. A. O. Smith. Simply put, our more than 90 years of
experience makes us a world leader in motors and motor accessories.
And, we put coast-to-coast service behind everything we sell
with expert assistance, availability and delivery from a network of
Authorized Service Centers throughout the U.S. So whether you’re
producing original equipment or simply replacing an existing drive,
we’ve got the perfect pick. MSC 700 speed controls, only from
A. O. Smith.
Features
• Inexpensive, compact speed control for PMDC and wound
field DC motors (up to 3 HP).
• Three chassis and five enclosed models, single and dual-voltage
units available (115V or 115/230V).
• No plug-in shunts needed for HP calibration.
• Automatic AC input voltage selection-without jumpers or switches
on dual voltage chassis models.
• Inhibit feature for automatic operation by switch, relay, or
programmable control.
• 5K Ohm speed potentiometer included with all controls.
• All chassis units feature quick-connect terminals.
• Interchangeable with many competitive units.
• Wide array of options for optimum design versatility.
• NEMA Code K, full-wave power conversion.
Typical Applications
• Packing equipment
• Textile machinery
• Exercise equipment
• Metal-forming equipment
• Conveyors
• Agricultural equipment
• Material handling
• Machine tools
• Printing and screening machinery
• Feeders
• Food processing equipment
• Positioners
• Pumps and fans
• Door openers
Operating Conditions
Line Voltage
115 VAC <10%
115/230 VAC <10%
Line Frequency
50/60 Hz <2 Hz
Ambient Temp. Range
0°C to 40° C
Altitude
3300 feet maximum
Service Factor
1.0
Duty
Continuous
Environment
Industrial/Commercial
Performance Characteristics
Overload capacity
150% for 1 minute
Speed Range
50:1 armature feedback
(Controlled)
100:1 with tachometer feedback
Speed Regulation
1% of base speed (typical)
Minimum speed trimpot
0 to 40% of full speed
(0 to 30% on W706 & W770)
Maximum speed trimpot
60 to 100% of full speed (50 to
110% on W706 & W770)
Current/Torque Limit
0 to 150% on W755,
(% of full load)
W756, W760, W761
50 TO 150% on W706
0 to 200% on W770
1 to 125% only @ 1.5 HP
(115)/3HP; (230V) on W715
Acceleration/
0.8 to 10 seconds (0.5 to 4
Deceleration Time
on W706, 0.2 to 10 seconds on
W770*)
IR Compensation
0 to 100 % (of rated load)
*Acceleration/Deceleration times are independent on W770
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