Xylem IM255 AQUAVAR Intelligent Pump Controller - Manual (Page 10)

Product Description
Product overview
A frequency converter is an electronic motor controller that converts AC mains input into
DC and then into a variable voltage, variable frequency output waveform. The following is
a list of functions of the frequency converter:
• Regulates the frequency and voltage to control the motor speed or torque.
• Varies the speed of the motor in response to system feedback, such as changing
temperature or pressure for controlling fan, compressor, or pump motors.
• Regulates the motor by responding to remote commands from external controls.
• Monitors the system and motor status.
• Issues warnings or alarms for fault conditions.
• Starts and stops the motor.
• Optimizes energy efficiency.
Operation and monitoring functions are available as status indications to an outside
control system or serial communication network.
Approvals and certifications
The frequency converter complies with UL508C thermal memory retention requirements.
Motor thermal protection
Motor thermal protection can be implemented using various techniques: PTC sensor in
motor windings, mechanical thermal switch, (Klixon type) or Electronic Thermal Relay
(ETR).
Protection against motor overheating comes from 1-90 Motor Thermal Protection. If the
ETR function is desired, set 1-90 Motor Thermal Protection to data value [4] ETR trip
(default value) or data value [3] ETR warning.
NOTICE: The ETR function is initialized at 1.16 x rated motor current and rated motor
frequency. The ETR function provides class 20 motor overload protection in accordance
with the NEC.
Motor thermal protection prevents the motor from overheating. The ETR function is an
electronic feature that simulates a bimetal relay that is based on internal measurements.
The characteristic is shown in the following figure.
Product Description
8 Aquavar ® Intelligent Pump Controller INSTRUCTION MANUAL