Variable Speed Controls
R&M's ControlMaster™ variable frequency drive series offers more versatility, better performance and prolonged equipment life than industry-standard contactor motor controls.
That's why R&M, the industry leader in innovation, uses variable frequency drives as standard for trolley and bridge controls and offers as an option the most comprehensive offering of variable frequency drives for hoisting controls.
Flexibility in speed selection and slower speeds offer precise load positioning and reduced load swing.
- Infinitely variable (stepless - EP) or multi-step (defined speeds - MS) speed control
- Wider range of selectable speed range - very slow speeds can be achieved
About Variable Speed Controls
BETTER PERFORMANCE AND PROLONGED EQUIPMENT LIFE
Dynamic braking, controlled acceleration and deceleration, and motor over-current and over- temperature protection are some of the VFD features that provide better performance and prolong the equipment life.
- Dynamic braking is a technique of electric braking in which the retarding force is supplied by the inverter. As the operator releases the control device (pushbutton), the output frequency of the inverter decreases to nearly zero which brings the motor to almost a complete stop before the brake is engaged.
- Controlled acceleration / deceleration provides smooth starts and stops and lowers starting currents, reducing gear and motor wear and structural stress on mechanical components - leading to longer equipment life.
- Motor over-current and over-temperature protection ensures that the motor is operating at its top performance levels.
Variable Frequency Control Versus Two-speed Contactor Control
Infinitely variable (EP) speed control gives the operator the ability to smoothly accelerate, decelerated and hold any speed between the defined minimum and maximum speed.
Two-speed contactor control does not offer the operator the ability to smoothly accelerate or decelerate between the defined speeds
Open Loop System
ControlMaster Elite and ControlMaster Aspire VFD’s, used in open loop systems, have a built-in motor model which calculates the values of the real motor one thousand times a second. The input data needed for the algorithm is the instantaneous value of the motor voltage and the measured motor current. Motor magnetic flux and shaft torques are calculated in the motor model based on the nameplate data of the motor. The VFD uses the calculated information to change its output in order to control the motor.
CONTROLMASTER™ ELITE VFD
ControlMaster Elite comes with additional software parameters, and is well suited for sophisticated hoisting operations.
ControlMaster Elite is an open loop system as standard. In an open loop system the minimum allowable low frequency setting for the hoist speed is 10 Hertz, which means the speed ratio is about 12:1. The acceleration and deceleration times are usually set at the minimum 1.5 seconds.
ControlMaster Elite can also be used in a closed loop system for enhanced safety and better load handling precision. In a closed loop system, the lower frequency setting for the hoist speed can be less than 10 Hertz, which means the maximum speed ratio could be about 120:1. The acceleration and deceleration times are usually set at the minimum 1.5 seconds.
CONTROLMASTER™ ELITE VFD + A-motor = ASR
The adjustable hoist speed range (ASR) is a standard feature of the CM Elite VFD and our new inverter-duty A-motor with overspeed capability. This combination of VFD and motor is always an open loop vector control system.
- ControlMaster Elite VFD + A-motor = ASR
- Intelligent speed control - the right speed at the right time!
- Extended speed range at light loads (<40%)
- Adjustable speed range at heavier loads (> 40%)
- Rated speed at full load is half the rated speed of equivalent 2-speed hoist
- R&M's most cost-effective open loop vector hoist control system
CONTROLMASTER™ ELITE VFD + S-motor = ESR
The extended hoist speed range (ESR) is a standard feature of the CM Elite VFD and our new inverter-duty S-motor with overspeed capability. This combination of VFD and motor is always a closed loop vector control system.
- ControlMaster Elite VFD + S-motor = ESR
- Extended speed range at light loads (<40%)
- Rated speed at full load equals the rated speed of equivalent 2-speed hoist
- R&M's most cost-effective closed loop vector hoist control system
CONTROLMASTER™ ELITE STANDARD FEATURES
- “Elite” control method - Open loop or closed loop vector control
- 5th slot card available for automation
- Accepts analog controls - joystick, etc.
The ControlMaster Aspire is a variable frequency drive that uses the A-motor inverter technology and is for the A3 and A5 hoist motors.
- Supply voltage: 380 - 480 VAC
- Control voltage: 42 - 240 VAC
- LCD panel with backlight
- 6 display units
- Brake resistor
- Display options (1-3) indicating drive status, control selection and current menu
- Buttons (4-5) with four arrow navigation buttons and buttons for back/reset and confirmation, used in navigating in the menu structure and in adjusting parameter values.
Closed Loop System
ControlMaster Elite VFDs, used in closed loop systems, have a built-in motor model which calculates the values of the real motor one thousand times a second. The input data needed for the algorithm is the instantaneous value of the motor voltage and the measured motor current. (Unlike an open loop system, torque regulation comes directly from speed feedback from the motor through an encoder.) This closed loop system allows the VFD to know what the motor is really doing and can immediately change its output to compensate for any motor operation.
Speed Supervision Unit
ControlMaster Elite VFD controls include a Speed Supervision Unit, (SSU) which is separate from the inverter and not dependent on the software. The Speed Supervision Unit monitors the speed of the motor for additional safety. If a speed difference, over-speed, or stall condition is detected, the Speed Supervision Unit stops the motion immediately. In an open loop system, a sensor bearing in the hoist motor supplies the speed feedback to the Speed Supervision Unit. In a closed loop system, an encoder on the hoist motor supplies the speed feedback.
CONTROLMASTER™ LDR VFD is used for controlling trolley or bridge drives and is programmable with a display.
The CM LDR is easy to use and offers many benefits.
- Display interface with digital inputs
- Standard Klixon thermal protection
- Smooth acceleration and deceleration
- Five models available to accommodate various application
- See ControlMaster LDR service manual for additional information
- Supply Voltage - 380-480 VAC
- Control Voltage - 48-230 VAC
- Current rating - 3.4A; 6.8A; 10.4A; 19.2A; 33.8A
- Motor thermal protection - Klixon type (ES-input)
- Brake relay - Yes
- Display - Yes
- Dip switches - No
CONTROLMASTER™ NXT (CMNXT) The ControlMaster NXT is a new adjustable frequency drive and is used for controlling the trolley motor of the bridge motor. A transformer will be furnished on the main connection side when needed to bring in proper power to the inverter. ControlMaster NXT Manual
- Non-digital interface (dip switches)
- Multi-speed reference or infinitely variable reference