Master/Slave Configuration
The EC motor control signals are wired in a Master/ Slave configuration. .This configuration allows for the maximum sound and energy reduction as well as the most stable head pressure control. .The control signal is delivered to the master motor (located at the header end of the unit). .The master motor relays the control signal to the adjacent slave motor. .This relay is done until the last motor is reached. .As each slave relays the control signal, it adjusts the signal so the next slave will run slightly slower than the upstream motor. .The end result of this is that when a motor receives a small enough signal, it will turn off. .This provides
Protective Features
The EC motors have many
The EC motors have functions within the motor to protect against:
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•incorrect rotor position detection
With any of these failures, the motor stops electronically and the alarm relay is switched. .With one of these failures, the motor WILL NOT automatically restart. .To reset, the power supply has to be switched off for a minimum 20 seconds once the motor is at standstill..
Locked-rotor protection
As soon as the rotor is blocked, the motor gets switched off electronically and the alarm relay is switched. .After
Under-voltage protection
If power supply voltage falls below ~150VAC/3Ø (for 230V motors) or ~290VAC/3Ø (for 460V motors) for 5 seconds minimum, the motor will be switched off electronically and the alarm relay is switched. .If power supply voltage returns to correct values, the motor WILL restart automatically..
Phase failure
If 1 phase fails for 5 seconds minimum, the motor will be switched off electronically and the alarm relay is switched. .If all 3 phases return to correct values, the motor WILL restart automatically within
EC Motor Wiring
All EC motor wiring is done at the factory. .If any motor wiring needs to be done in the field, the diagram below indicates the terminal pin configurations inside the motor junction box. .Terminals in shaded area are not normally used..
The following diagram shows typical motor wiring for a 1 x 4 EC condenser..
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