Compact Soft Starter

AC Supply Voltage: 200 - 600VAC

HP Ratings: 3 - 1200HP

Amp Ratings: 18 - 1250Amps

Overload Rating: 500% for 60sec.


Flexibility of Control
Multiple ramp profiles, Pump-FlexTM Decel and advanced motor protection make the VMX Series soft starter adaptable to a wide variety of AC motor applications... no need for add-on modules or costly auxiliary devices.

Compact packaging has become critical in more and more electrical installations. The VMX Series meets this need without compromising features and ratings. By using a highly engineered packaging design and the latest generation microprocessor, all the control and protection features you need are in the VMX Series. Narrow and shallow dimensions are perfect for integrating the VMX Series into motor control centers (MCCs), pump control panels, and retrofit starter enclosures.

Integral Bypass Contactors are standard on all sizes and provide maximum efficiency of panel space while maintaining the Motortronics reputation for being able to soft start most any load. The VMX Series is the only fully integrated, compact, world-class design offering uncompromised power and control capabilities.

Power Components
6 SCRs in inverse parallel pairs for full phase angle
soft start control
1600V PIV rating on all units
RC snubber for dv/dt protection of each SCR pair

Dry contact closure selects a non-ramping Jog
function at an adjustable torque

Line Voltage Range
200 to 600 VAC, 3 phase +10% -15% on all units,

Kick Start
10 - 100% starting torque for 0.1 - 2 seconds

Current Ratings
18 - 1250A depending on unit selection
Range of each unit is 50-100% of maximum

Pump-Flex™ Deceleration Ramp
Fully adjustable to match field conditions:
Begin Decel setting, 0 - 100% of line voltage
Decel ramp time, 1 - 60 seconds
End Decel setting (Off ), 0 - 1% of Begin setting

AC Supply Voltage
User supplied 120VAC +10% -15% tolerance, 60Hz
Optional 240VAC 50Hz control available

Restart Delay Timer (Sequential Start Delay)
Programmable time delay 1 - 999 seconds after loss
of control power for staggered restarts

Overload Capacity (% of motor FLA)
500% for 60 seconds

RS-485 Serial Communications
Up to 247 starters per link
Modbus RTU protocol built-in
Full programming over the serial link
Programmable remote starter control

Bypass Contactor
Standard on all units
Shunt rated bypass/ Line start rated bypass

Start/Stop Control Choices
2-wire Run-Stop using dry contacts
3-wire Start/Stop with built-in seal in contact
N.C. Interlock input (dry contact) for remote devices

Operator Interface
Tactile feedback keypad
Easy to read LED display
Run and fault
status indicators

Ramp Control Choices (4 built-in)
Voltage Ramp
Voltage Ramp with Current Limit
CLT© Closed Loop Torque Ramp (Current Ramp)
Current Step (current limit only)
Ramp times adjustable 1 - 120 seconds
Current Limit adjustable 200 - 600% of FLA

Electronic Shear Pin Protection
Trip level: 100 - 300% of motor FLA with trip delay

Dual Ramps
Select via dry contact closure between any
combinations of the above

Motor Duty Cycle Protection
Back-spin/coast-down, starts-per-hour or minimum
time between starts lockouts. Restart delay after a
power failure.

Start & Run Protection
Two programmable overload trip curves allow for the
thermal capacity required to start the load while providing
motor overload protection needed during the run time.
Start: Programmable for Class 5 - 30
Run: Programmable for Class 5 - 30, enabled when starter
detects motor is "At-Speed"
Reset: Manual or automatic, selectable via programming.
Remote reset available.

Short Circuit
Trips at 10x unit current rating during run. Checks for
shorted load prior to each start.

Real-Time Thermal Modeling
Continuously calculates motor operating temperature even
when the motor is not running.

Shorted SCR
Locks out on any single shorted SCR (defeatable) or
can provide shunt trip function if multiple SCRs short
or bypass contactor is welded closed.

Retentive Thermal Memory
Remembers the thermal condition of the motor even in the
event of a power brown-out or black-out when power is
restored. Extrapolates motor temperature using a real-time

Monitors phase current, ground current and motor
thermal capacity.

Dynamic Reset Capacity
Overload will not reset until thermal capacity in the motor is
sufficient for a successful restart. Starter learns and retains this
information from previous starts.

Phase Loss
Trips on phase current or voltage loss

Motor Temperature
PTC thermistor input can also be used for E-stop or external
overload relay.

Phase Rotation
Phase rotation trip can be set to A-B-C, A-C-B or disabled.

Equipment Ground Fault
Residual current method with adjustable trip delay.


Phase Current Imbalance/Loss Protection
Trip level: 5 - 30% current imbalance between any two
phases with trip delay