AC Fan & Motor Speed Controls
Control Resources is a leading manufacturer of AC motor speed control products that control motors, fans or pumps for a variety of industry applications with current rating up to 18 amps. Our AC motor speed controls regulate motor speed based on inputs that include temperature, analog (0-20mA, 0-10VDC) signal or remote transducer control. Mounting options include DIN rail, open frame, with and without metal enclosures. Control Resources is an OEM (Original Equipment Manufacturer) supplier of fan and motor speed control and alarm products. Our products are not intended for end-user/after market applications.
When a DC fan or motor is available and DC power is available, nothing beats a DC control for energy savings, cost, size, safety or controllability. When circumstances do not permit the use of a DC fan or motor, CRI offers 3 AC motor speed control technologies to consider; TRIAC (voltage or phase control), VFD (Variable Frequency Drive), or ECM (Electronically Commutated Motor).
Standard SmartFan AC Fan & Motor Speed Control Products
| Model |
Current Rating |
Motor Type |
Control Technology |
Control Options |
Input Voltage Range |
Programming Options |
|
4A @ 40ºC |
1 Phase or 3 Phase Inverter duty |
VFD |
Temperature, analog (0-5V, 0-10V, 4-20mA), transducer, potentiometer, MODBUS, fixed speed |
104 – 253 VAC |
 SmartFan NavigatorProgrammer MODBUS, or Factory set-up |
|
 Nimbus II |
7.0A @ 40ºC |
1 Phase TRIAC controllable induction motor |
TRIAC |
Temperature, analog (up to 10VDC, up to 20mA), transducer, fixed speed |
65 – 277 VAC |
|
 Nimbus |
7.5A @ 40ºC |
1 Phase TRIAC controllable induction motor |
TRIAC |
Temperature, analog (2-10 VDC, 4-20mA), transducer, fixed speed |
95 – 250 VAC |
Dip Switches or |
| Note: Nimbus is not recommended for new designs. Please see the Nimbus II above. | ||||||
 Cirrus-ECM |
N/A |
ECM |
ECM |
Temperature, analog (0-10V, 0-20mA), transducer, fixed speed |
22- 26 VAC |
SmartFan Navigator Programmer or Factory set-up |
 Custom AC MotorSpeed Control |
Control Resources specializes in customizing existing designs as well as providing all new custom controls to meet your specification. For more information visit our Custom SmartFan Controls and Alarms page or talk to one of our engineers. Email: sales@controlres.com or call 978-486-4160. |
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Control Technology Overview: TRIAC, VFD & ECM AC Motor Speed Control
|
TRIAC Control: Nimbus II, Nimbus
If system cost is the number one concern, choosing an induction motor [Permanent Split Capacitor (PSC) or Shaded Pole] and a compatible TRIAC control may be the way to go. TRIAC controls also tend to be more energy efficient at higher speeds than VFDs. Drawbacks of this technology include relatively high minimum speeds and potentially nonlinear control curve (input signal vs. motor speed). Please check out our AC Motor Compatibility page for an explanation of the TRIAC AC motor speed control motor requirements and risks. |
 |
VFD Control: Stratus-II
Not all AC motors are TRIAC controllable. In many of these cases, an inverter duty motor can be successfully controlled with a Variable Frequency Drive (VFD). VFDs tend to be more energy efficient than TRIAC controls at lower speeds and can be run at lower speeds. Drawback to VFDs include, controller cost, size and potential bearing noise. Please check out our AC Motor Compatibility page for an explanation of the Variable Frequency Drive AC motor speed control motor requirements and risks. |
|
ECM Control: Cirrus-ECM
In recent years, the availability of ECM motors has greatly increased. These are basically DC motors with built-in transformers allowing them to be powered from the AC line. As a result, these motors are the most energy efficient and easiest (inexpensive and accurate) to control. But of course there is no such thing as a free lunch. ECM motors can be pricey and are not always available in the size required. |
TRIAC, VFD & ECM AC Motor Speed Control Comparison
| TRIAC / Phase Control | Variable Frequency Drive | ECM Control | |
| Energy Use | Good* | Good* | Best |
| Controller Accuracy | Good | Better | Best |
| Low Speed Capability (<50%) | Good | Better | Best |
| Motor Availability | Better | Best | Low |
| Induced Bearing Noise | Better | Good | Best |
| Controller Size | Small | Large | Small |
| Controller Cost | Low | High | Low |
| Motor Cost | Low | Low | High |
*TRIACs are often more energy efficient at higher speeds, Variable Frequency Drives are more efficient at lower speeds.
Applications – TRIAC, Variable Frequency Drives, & ECM AC Motor Speed Control
 Pump Control SmartFan AC motor speed control products are capable of controlling small AC pumps. |
 Clean Room Pressurization SmartFan AC motor speed control products can be used to help keep positive pressure in clean rooms. |
 Humidity Control SmartFan AC motor speed control products can automatically regulate fan speed when connected to a humidity sensor. |
 Ventilation SmartFan AC motor speed control products can be used with a ceiling fan, attic ventilator or duct fan to remove hot air or noxious fumes. |
