Micropump DB-380.B - Manual (Page 5)

5 of 20 MODEL 380 MOTOR INSTALLATION AND OPERATION MANUAL IOM # 7820
REV A
(10/99)
MICROPUMP, INC.
A Unit of IDEX Corporation
PO Box 8975, Vancouver, WA 98668-8975, USA
Phone: (360) 253-2008
Fax: (360) 253-2401
email: [email protected]
Website: www.micropump.com
MICROPUMP LIMITED
A Subsidiary of Micropump, Inc.
Howard Road, Eaton Socon
St. Neots, Cambs. PE19 3ET England
Phone: (44) (0) 1480-356900
Fax: (44) (0) 1480-356920
Website:
www.micropump.com
Restart Temperature**
(After Thermal Shutdown) Min = 76 Avg = 80 Max = 84 ºC
Thermal resistance to
ambient air 3ºC /W
*If the motor is run at less than full load, the motor can be operated in a higher temperature ambient. Please contact your
Micropump distributor if you plan to operate the motor in an ambient temperature above 40ºC.
**The thermal shutdown refers to the temperature of the motor flange at which the internal thermal protection will shut down the
motor. The motor will restart automatically when the flange has cooled to below the listed restart temperature
***To run the motor in two-wire mode, the control (white) wire can be connected to the positive supply (red) wire. The motor will
run at its maximum speed. The speed control will not be damaged if the applied voltage is within +/-30VDC of the common (black)
wire, though maximum speed is achieved at +5VDC or higher, and the motor will stop if 0VDC or lower is applied.
DESCRIPTION
A Model 380 is an outside rotor, Brushless DC Motor. The motor is enclosed in a clear-anodized, aluminum covering. Depending
on the specific model purchased, there may be an attached magnet hub, a pump adapter, and/or a pump. The motors rotate in one
direction and have a 0-5 volt speed control input. There is a tachometer signal with a 0-5 volt square-wave output for speed
feedback. The tachometer output has 2 pulses per revolution, and the output frequency can be multiplied by 30 to obtain RPM. The
main power is 24VDC.
Function
The output shaft drives a magnet hub which drives a magnet in the pump. The driven magnet is connected to the pumping parts and
is sealed in the magnet cup. The magnets align pole-to-pole and rotate at the same speed until the coupling torque is exceeded.
Rotation of the pumping elements produces liquid flow. Magnet hubs are supplied by Micropump, and included with the motor
assembly.
Magnet Decoupling
Magnetic decoupling occurs when the load on the pump exceeds the coupling torque between the magnets. The magnets are forced
out of pole-to-pole alignment and are decoupled. When decoupling occurs, the driving magnet speed increases to motor no-load
speed while the driven magnet and pumping parts remain motionless. To recouple the magnets, the motor must be stopped to allow
the magnets to re-align. The motor can then be restarted. The magnet couplings used with the Model 380 motor will typically be
sized so that the motor stalls before the magnets decouple. However, some dynamic conditions (i.e. sudden changes in load) can
cause the magnets to decouple, despite the limited motor torque.
The motor is not designed to run in a stall condition continually. In
a stall condition, the motor thermal protection may not protect the
internal electronics from overheating. Do not run motor
continuously in a stalled condition.
CAUTION